/*

Copyright (C) 2004-2012 David Bateman
Copyright (C) 1998-2004 Andy Adler
Copyright (C) 2010 VZLU Prague

This file is part of Octave.

Octave is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation; either version 3 of the License, or (at your
option) any later version.

Octave is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
for more details.

You should have received a copy of the GNU General Public License
along with Octave; see the file COPYING.  If not, see
<http://www.gnu.org/licenses/>.

*/

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <cfloat>

#include <iostream>
#include <vector>

#include "quit.h"
#include "lo-ieee.h"
#include "lo-mappers.h"
#include "f77-fcn.h"
#include "dRowVector.h"
#include "oct-locbuf.h"

#include "dDiagMatrix.h"
#include "CDiagMatrix.h"
#include "CSparse.h"
#include "boolSparse.h"
#include "dSparse.h"
#include "functor.h"
#include "oct-spparms.h"
#include "SparseCmplxLU.h"
#include "oct-sparse.h"
#include "sparse-util.h"
#include "SparseCmplxCHOL.h"
#include "SparseCmplxQR.h"

#include "Sparse-diag-op-defs.h"

#include "Sparse-perm-op-defs.h"
#include "mx-inlines.cc"

// Define whether to use a basic QR solver or one that uses a Dulmange
// Mendelsohn factorization to seperate the problem into under-determined,
// well-determined and over-determined parts and solves them seperately
#ifndef USE_QRSOLVE
#include "sparse-dmsolve.cc"
#endif

// Fortran functions we call.
extern "C"
{
  F77_RET_T
  F77_FUNC (zgbtrf, ZGBTRF) (const octave_idx_type&, const octave_idx_type&,
                             const octave_idx_type&, const octave_idx_type&,
                             Complex*, const octave_idx_type&,
                             octave_idx_type*, octave_idx_type&);

  F77_RET_T
  F77_FUNC (zgbtrs, ZGBTRS) (F77_CONST_CHAR_ARG_DECL,
                             const octave_idx_type&, const octave_idx_type&,
                             const octave_idx_type&, const octave_idx_type&,
                             const Complex*, const octave_idx_type&,
                             const octave_idx_type*, Complex*,
                             const octave_idx_type&, octave_idx_type&
                             F77_CHAR_ARG_LEN_DECL);

  F77_RET_T
  F77_FUNC (zgbcon, ZGBCON) (F77_CONST_CHAR_ARG_DECL,
                             const octave_idx_type&, const octave_idx_type&,
                             const octave_idx_type&, Complex*,
                             const octave_idx_type&, const octave_idx_type*,
                             const double&, double&, Complex*, double*,
                             octave_idx_type&
                             F77_CHAR_ARG_LEN_DECL);

  F77_RET_T
  F77_FUNC (zpbtrf, ZPBTRF) (F77_CONST_CHAR_ARG_DECL,
                             const octave_idx_type&, const octave_idx_type&,
                             Complex*, const octave_idx_type&, octave_idx_type&
                             F77_CHAR_ARG_LEN_DECL);

  F77_RET_T
  F77_FUNC (zpbtrs, ZPBTRS) (F77_CONST_CHAR_ARG_DECL,
                             const octave_idx_type&, const octave_idx_type&,
                             const octave_idx_type&, Complex*,
                             const octave_idx_type&, Complex*,
                             const octave_idx_type&, octave_idx_type&
                             F77_CHAR_ARG_LEN_DECL);

  F77_RET_T
  F77_FUNC (zpbcon, ZPBCON) (F77_CONST_CHAR_ARG_DECL,
                             const octave_idx_type&, const octave_idx_type&,
                             Complex*, const octave_idx_type&, const double&,
                             double&, Complex*, double*, octave_idx_type&
                             F77_CHAR_ARG_LEN_DECL);

  F77_RET_T
  F77_FUNC (zgttrf, ZGTTRF) (const octave_idx_type&, Complex*, Complex*,
                             Complex*, Complex*, octave_idx_type*,
                             octave_idx_type&);

  F77_RET_T
  F77_FUNC (zgttrs, ZGTTRS) (F77_CONST_CHAR_ARG_DECL,
                             const octave_idx_type&, const octave_idx_type&,
                             const Complex*, const Complex*, const Complex*,
                             const Complex*, const octave_idx_type*,
                             Complex *, const octave_idx_type&,
                             octave_idx_type&
                             F77_CHAR_ARG_LEN_DECL);

  F77_RET_T
  F77_FUNC (zptsv, ZPTSV) (const octave_idx_type&, const octave_idx_type&,
                           double*, Complex*, Complex*,
                           const octave_idx_type&, octave_idx_type&);

  F77_RET_T
  F77_FUNC (zgtsv, ZGTSV) (const octave_idx_type&, const octave_idx_type&,
                           Complex*, Complex*, Complex*, Complex*,
                           const octave_idx_type&, octave_idx_type&);
}

SparseComplexMatrix::SparseComplexMatrix (const SparseMatrix& a)
  : MSparse<Complex> (a)
{
}

SparseComplexMatrix::SparseComplexMatrix (const SparseBoolMatrix& a)
  : MSparse<Complex> (a.rows (), a.cols (), a.nnz ())
{
  octave_idx_type nc = cols ();
  octave_idx_type nz = a.nnz ();

  for (octave_idx_type i = 0; i < nc + 1; i++)
    cidx (i) = a.cidx (i);

  for (octave_idx_type i = 0; i < nz; i++)
    {
      data (i) = Complex (a.data (i));
      ridx (i) = a.ridx (i);
    }
}

SparseComplexMatrix::SparseComplexMatrix (const ComplexDiagMatrix& a)
  : MSparse<Complex> (a.rows (), a.cols (), a.length ())
{
  octave_idx_type j = 0, l = a.length ();
  for (octave_idx_type i = 0; i < l; i++)
    {
      cidx (i) = j;
      if (a(i, i) != 0.0)
        {
          data (j) = a(i, i);
          ridx (j) = i;
          j++;
        }
    }
  for (octave_idx_type i = l; i <= a.cols (); i++)
    cidx (i) = j;
}
bool
SparseComplexMatrix::operator == (const SparseComplexMatrix& a) const
{
  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();
  octave_idx_type nz = nnz ();
  octave_idx_type nr_a = a.rows ();
  octave_idx_type nc_a = a.cols ();
  octave_idx_type nz_a = a.nnz ();

  if (nr != nr_a || nc != nc_a || nz != nz_a)
    return false;

  for (octave_idx_type i = 0; i < nc + 1; i++)
    if (cidx (i) != a.cidx (i))
        return false;

  for (octave_idx_type i = 0; i < nz; i++)
    if (data (i) != a.data (i) || ridx (i) != a.ridx (i))
      return false;

  return true;
}

bool
SparseComplexMatrix::operator != (const SparseComplexMatrix& a) const
{
  return !(*this == a);
}

bool
SparseComplexMatrix::is_hermitian (void) const
{
  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();

  if (nr == nc && nr > 0)
    {
      for (octave_idx_type j = 0; j < nc; j++)
        {
          for (octave_idx_type i = cidx (j); i < cidx (j+1); i++)
            {
              octave_idx_type ri = ridx (i);

              if (ri != j)
                {
                  bool found = false;

                  for (octave_idx_type k = cidx (ri); k < cidx (ri+1); k++)
                    {
                      if (ridx (k) == j)
                        {
                          if (data (i) == conj (data (k)))
                            found = true;
                          break;
                        }
                    }

                  if (! found)
                    return false;
                }
            }
        }

      return true;
    }

  return false;
}

static const Complex Complex_NaN_result (octave_NaN, octave_NaN);

SparseComplexMatrix
SparseComplexMatrix::max (int dim) const
{
  Array<octave_idx_type> dummy_idx;
  return max (dummy_idx, dim);
}

SparseComplexMatrix
SparseComplexMatrix::max (Array<octave_idx_type>& idx_arg, int dim) const
{
  SparseComplexMatrix result;
  dim_vector dv = dims ();
  octave_idx_type nr = dv(0);
  octave_idx_type nc = dv(1);


  if (dim >= dv.length ())
    {
      idx_arg.resize (dim_vector (nr, nc), 0);
      return *this;
    }

  if (dim < 0)
    dim = dv.first_non_singleton ();

  if (dim == 0)
    {
      idx_arg.resize (dim_vector (nr == 0 ? 0 : 1, nc), 0);

      if (nr == 0 || nc == 0 || dim >= dv.length ())
        return SparseComplexMatrix (nr == 0 ? 0 : 1, nc);

      octave_idx_type nel = 0;
      for (octave_idx_type j = 0; j < nc; j++)
        {
          Complex tmp_max;
          double abs_max = octave_NaN;
          octave_idx_type idx_j = 0;
          for (octave_idx_type i = cidx (j); i < cidx (j+1); i++)
            {
              if (ridx (i) != idx_j)
                break;
              else
                idx_j++;
            }

          if (idx_j != nr)
            {
              tmp_max = 0.;
              abs_max = 0.;
            }

          for (octave_idx_type i = cidx (j); i < cidx (j+1); i++)
            {
              Complex tmp = data (i);

              if (xisnan (tmp))
                continue;

              double abs_tmp = std::abs (tmp);

              if (xisnan (abs_max) || abs_tmp > abs_max)
                {
                  idx_j = ridx (i);
                  tmp_max = tmp;
                  abs_max = abs_tmp;
                }
            }

          idx_arg.elem (j) = xisnan (tmp_max) ? 0 : idx_j;
          if (abs_max != 0.)
            nel++;
        }

      result = SparseComplexMatrix (1, nc, nel);

      octave_idx_type ii = 0;
      result.xcidx (0) = 0;
      for (octave_idx_type j = 0; j < nc; j++)
        {
          Complex tmp = elem (idx_arg(j), j);
          if (tmp != 0.)
            {
              result.xdata (ii) = tmp;
              result.xridx (ii++) = 0;
            }
          result.xcidx (j+1) = ii;
        }
    }
  else
    {
      idx_arg.resize (dim_vector (nr, nc == 0 ? 0 : 1), 0);

      if (nr == 0 || nc == 0 || dim >= dv.length ())
        return SparseComplexMatrix (nr, nc == 0 ? 0 : 1);

      OCTAVE_LOCAL_BUFFER (octave_idx_type, found, nr);

      for (octave_idx_type i = 0; i < nr; i++)
        found [i] = 0;

      for (octave_idx_type j = 0; j < nc; j++)
        for (octave_idx_type i = cidx(j); i < cidx(j+1); i++)
          if (found [ridx (i)] == -j)
            found [ridx (i)] = -j - 1;
      
      for (octave_idx_type i = 0; i < nr; i++)
        if (found [i] > -nc && found [i] < 0)
          idx_arg.elem (i) = -found [i];

      for (octave_idx_type j = 0; j < nc; j++)
        {
          for (octave_idx_type i = cidx (j); i < cidx (j+1); i++)
            {
              octave_idx_type ir = ridx (i);
              octave_idx_type ix = idx_arg.elem (ir);
              Complex tmp = data (i);

              if (xisnan (tmp))
                continue;
              else if (ix == -1 || std::abs (tmp) > std::abs (elem (ir, ix)))
                idx_arg.elem (ir) = j;
            }
        }

      octave_idx_type nel = 0;
      for (octave_idx_type j = 0; j < nr; j++)
        if (idx_arg.elem (j) == -1 || elem (j, idx_arg.elem (j)) != 0.)
          nel++;

      result = SparseComplexMatrix (nr, 1, nel);

      octave_idx_type ii = 0;
      result.xcidx (0) = 0;
      result.xcidx (1) = nel;
      for (octave_idx_type j = 0; j < nr; j++)
        {
          if (idx_arg(j) == -1)
            {
              idx_arg(j) = 0;
              result.xdata (ii) = Complex_NaN_result;
              result.xridx (ii++) = j;
            }
          else
            {
              Complex tmp = elem (j, idx_arg(j));
              if (tmp != 0.)
                {
                  result.xdata (ii) = tmp;
                  result.xridx (ii++) = j;
                }
            }
        }
    }

  return result;
}

SparseComplexMatrix
SparseComplexMatrix::min (int dim) const
{
  Array<octave_idx_type> dummy_idx;
  return min (dummy_idx, dim);
}

SparseComplexMatrix
SparseComplexMatrix::min (Array<octave_idx_type>& idx_arg, int dim) const
{
  SparseComplexMatrix result;
  dim_vector dv = dims ();
  octave_idx_type nr = dv(0);
  octave_idx_type nc = dv(1);

  if (dim >= dv.length ())
    {
      idx_arg.resize (dim_vector (nr, nc), 0);
      return *this;
    }

  if (dim < 0)
    dim = dv.first_non_singleton ();

  if (dim == 0)
    {
      idx_arg.resize (dim_vector (nr == 0 ? 0 : 1, nc), 0);

      if (nr == 0 || nc == 0 || dim >= dv.length ())
        return SparseComplexMatrix (nr == 0 ? 0 : 1, nc);

      octave_idx_type nel = 0;
      for (octave_idx_type j = 0; j < nc; j++)
        {
          Complex tmp_min;
          double abs_min = octave_NaN;
          octave_idx_type idx_j = 0;
          for (octave_idx_type i = cidx (j); i < cidx (j+1); i++)
            {
              if (ridx (i) != idx_j)
                break;
              else
                idx_j++;
            }

          if (idx_j != nr)
            {
              tmp_min = 0.;
              abs_min = 0.;
            }

          for (octave_idx_type i = cidx (j); i < cidx (j+1); i++)
            {
              Complex tmp = data (i);

              if (xisnan (tmp))
                continue;

              double abs_tmp = std::abs (tmp);

              if (xisnan (abs_min) || abs_tmp < abs_min)
                {
                  idx_j = ridx (i);
                  tmp_min = tmp;
                  abs_min = abs_tmp;
                }
            }

          idx_arg.elem (j) = xisnan (tmp_min) ? 0 : idx_j;
          if (abs_min != 0.)
            nel++;
        }

      result = SparseComplexMatrix (1, nc, nel);

      octave_idx_type ii = 0;
      result.xcidx (0) = 0;
      for (octave_idx_type j = 0; j < nc; j++)
        {
          Complex tmp = elem (idx_arg(j), j);
          if (tmp != 0.)
            {
              result.xdata (ii) = tmp;
              result.xridx (ii++) = 0;
            }
          result.xcidx (j+1) = ii;
        }
    }
  else
    {
      idx_arg.resize (dim_vector (nr, nc == 0 ? 0 : 1), 0);

      if (nr == 0 || nc == 0 || dim >= dv.length ())
        return SparseComplexMatrix (nr, nc == 0 ? 0 : 1);

      OCTAVE_LOCAL_BUFFER (octave_idx_type, found, nr);

      for (octave_idx_type i = 0; i < nr; i++)
        found [i] = 0;

      for (octave_idx_type j = 0; j < nc; j++)
        for (octave_idx_type i = cidx(j); i < cidx(j+1); i++)
          if (found [ridx (i)] == -j)
            found [ridx (i)] = -j - 1;
      
      for (octave_idx_type i = 0; i < nr; i++)
        if (found [i] > -nc && found [i] < 0)
          idx_arg.elem (i) = -found [i];

      for (octave_idx_type j = 0; j < nc; j++)
        {
          for (octave_idx_type i = cidx (j); i < cidx (j+1); i++)
            {
              octave_idx_type ir = ridx (i);
              octave_idx_type ix = idx_arg.elem (ir);
              Complex tmp = data (i);

              if (xisnan (tmp))
                continue;
              else if (ix == -1 || std::abs (tmp) < std::abs (elem (ir, ix)))
                idx_arg.elem (ir) = j;
            }
        }

      octave_idx_type nel = 0;
      for (octave_idx_type j = 0; j < nr; j++)
        if (idx_arg.elem (j) == -1 || elem (j, idx_arg.elem (j)) != 0.)
          nel++;

      result = SparseComplexMatrix (nr, 1, nel);

      octave_idx_type ii = 0;
      result.xcidx (0) = 0;
      result.xcidx (1) = nel;
      for (octave_idx_type j = 0; j < nr; j++)
        {
          if (idx_arg(j) == -1)
            {
              idx_arg(j) = 0;
              result.xdata (ii) = Complex_NaN_result;
              result.xridx (ii++) = j;
            }
          else
            {
              Complex tmp = elem (j, idx_arg(j));
              if (tmp != 0.)
                {
                  result.xdata (ii) = tmp;
                  result.xridx (ii++) = j;
                }
            }
        }
    }

  return result;
}

/*

%!assert (max (max (speye (65536) * 1i)), sparse (1i)) 
%!assert (min (min (speye (65536) * 1i)), sparse (0)) 
%!assert (size (max (sparse (8, 0), [], 1)), [1, 0]) 
%!assert (size (max (sparse (8, 0), [], 2)), [8, 0]) 
%!assert (size (max (sparse (0, 8), [], 1)), [0, 8]) 
%!assert (size (max (sparse (0, 8), [], 2)), [0, 1]) 
%!assert (size (min (sparse (8, 0), [], 1)), [1, 0]) 
%!assert (size (min (sparse (8, 0), [], 2)), [8, 0]) 
%!assert (size (min (sparse (0, 8), [], 1)), [0, 8]) 
%!assert (size (min (sparse (0, 8), [], 2)), [0, 1]) 

*/

ComplexRowVector
SparseComplexMatrix::row (octave_idx_type i) const
{
  octave_idx_type nc = columns ();
  ComplexRowVector retval (nc, 0);

  for (octave_idx_type j = 0; j < nc; j++)
    for (octave_idx_type k = cidx (j); k < cidx (j+1); k++)
      {
        if (ridx (k) == i)
          {
            retval(j) = data (k);
            break;
          }
      }

  return retval;
}

ComplexColumnVector
SparseComplexMatrix::column (octave_idx_type i) const
{
  octave_idx_type nr = rows ();
  ComplexColumnVector retval (nr, 0);

  for (octave_idx_type k = cidx (i); k < cidx (i+1); k++)
    retval(ridx (k)) = data (k);

  return retval;
}

// destructive insert/delete/reorder operations

SparseComplexMatrix&
SparseComplexMatrix::insert (const SparseMatrix& a, octave_idx_type r, octave_idx_type c)
{
  SparseComplexMatrix tmp (a);
  return insert (tmp /*a*/, r, c);
}

SparseComplexMatrix&
SparseComplexMatrix::insert (const SparseComplexMatrix& a, octave_idx_type r, octave_idx_type c)
{
  MSparse<Complex>::insert (a, r, c);
  return *this;
}

SparseComplexMatrix&
SparseComplexMatrix::insert (const SparseMatrix& a, const Array<octave_idx_type>& indx)
{
  SparseComplexMatrix tmp (a);
  return insert (tmp /*a*/, indx);
}

SparseComplexMatrix&
SparseComplexMatrix::insert (const SparseComplexMatrix& a, const Array<octave_idx_type>& indx)
{
  MSparse<Complex>::insert (a, indx);
  return *this;
}

SparseComplexMatrix
SparseComplexMatrix::concat (const SparseComplexMatrix& rb,
                             const Array<octave_idx_type>& ra_idx)
{
  // Don't use numel to avoid all possiblity of an overflow
  if (rb.rows () > 0 && rb.cols () > 0)
    insert (rb, ra_idx(0), ra_idx(1));
  return *this;
}

SparseComplexMatrix
SparseComplexMatrix::concat (const SparseMatrix& rb, const Array<octave_idx_type>& ra_idx)
{
  SparseComplexMatrix tmp (rb);
  if (rb.rows () > 0 && rb.cols () > 0)
    insert (tmp, ra_idx(0), ra_idx(1));
  return *this;
}

ComplexMatrix
SparseComplexMatrix::matrix_value (void) const
{
  return Sparse<Complex>::array_value ();
}

SparseComplexMatrix
SparseComplexMatrix::hermitian (void) const
{
  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();
  octave_idx_type nz = nnz ();
  SparseComplexMatrix retval (nc, nr, nz);

  for (octave_idx_type i = 0; i < nz; i++)
    retval.xcidx (ridx (i) + 1)++;
  // retval.xcidx[1:nr] holds the row degrees for rows 0:(nr-1)
  nz = 0;
  for (octave_idx_type i = 1; i <= nr; i++)
    {
      const octave_idx_type tmp = retval.xcidx (i);
      retval.xcidx (i) = nz;
      nz += tmp;
    }
  // retval.xcidx[1:nr] holds row entry *start* offsets for rows 0:(nr-1)

  for (octave_idx_type j = 0; j < nc; j++)
    for (octave_idx_type k = cidx (j); k < cidx (j+1); k++)
      {
        octave_idx_type q = retval.xcidx (ridx (k) + 1)++;
        retval.xridx (q) = j;
        retval.xdata (q) = conj (data (k));
      }
  assert (nnz () == retval.xcidx (nr));
  // retval.xcidx[1:nr] holds row entry *end* offsets for rows 0:(nr-1)
  // and retval.xcidx[0:(nr-1)] holds their row entry *start* offsets

  return retval;
}

SparseComplexMatrix
conj (const SparseComplexMatrix& a)
{
  octave_idx_type nr = a.rows ();
  octave_idx_type nc = a.cols ();
  octave_idx_type nz = a.nnz ();
  SparseComplexMatrix retval (nc, nr, nz);

  for (octave_idx_type i = 0; i < nc + 1; i++)
    retval.cidx (i) = a.cidx (i);

  for (octave_idx_type i = 0; i < nz; i++)
    {
      retval.data (i) = conj (a.data (i));
      retval.ridx (i) = a.ridx (i);
    }

  return retval;
}

SparseComplexMatrix
SparseComplexMatrix::inverse (void) const
{
  octave_idx_type info;
  double rcond;
  MatrixType mattype (*this);
  return inverse (mattype, info, rcond, 0, 0);
}

SparseComplexMatrix
SparseComplexMatrix::inverse (MatrixType& mattype) const
{
  octave_idx_type info;
  double rcond;
  return inverse (mattype, info, rcond, 0, 0);
}

SparseComplexMatrix
SparseComplexMatrix::inverse (MatrixType& mattype, octave_idx_type& info) const
{
  double rcond;
  return inverse (mattype, info, rcond, 0, 0);
}

SparseComplexMatrix
SparseComplexMatrix::dinverse (MatrixType &mattyp, octave_idx_type& info,
                        double& rcond, const bool,
                        const bool calccond) const
{
  SparseComplexMatrix retval;

  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();
  info = 0;

  if (nr == 0 || nc == 0 || nr != nc)
    (*current_liboctave_error_handler) ("inverse requires square matrix");
  else
    {
      // Print spparms("spumoni") info if requested
      int typ = mattyp.type ();
      mattyp.info ();

      if (typ == MatrixType::Diagonal ||
          typ == MatrixType::Permuted_Diagonal)
        {
          if (typ == MatrixType::Permuted_Diagonal)
            retval = transpose ();
          else
            retval = *this;

          // Force make_unique to be called
          Complex *v = retval.data ();

          if (calccond)
            {
              double dmax = 0., dmin = octave_Inf;
              for (octave_idx_type i = 0; i < nr; i++)
                {
                  double tmp = std::abs (v[i]);
                  if (tmp > dmax)
                    dmax = tmp;
                  if (tmp < dmin)
                    dmin = tmp;
                }
              rcond = dmin / dmax;
            }

          for (octave_idx_type i = 0; i < nr; i++)
            v[i] = 1.0 / v[i];
        }
      else
        (*current_liboctave_error_handler) ("incorrect matrix type");
    }

  return retval;
}

SparseComplexMatrix
SparseComplexMatrix::tinverse (MatrixType &mattyp, octave_idx_type& info,
                               double& rcond, const bool,
                               const bool calccond) const
{
  SparseComplexMatrix retval;

  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();
  info = 0;

  if (nr == 0 || nc == 0 || nr != nc)
    (*current_liboctave_error_handler) ("inverse requires square matrix");
  else
    {
      // Print spparms("spumoni") info if requested
      int typ = mattyp.type ();
      mattyp.info ();

      if (typ == MatrixType::Upper || typ == MatrixType::Permuted_Upper ||
          typ == MatrixType::Lower || typ == MatrixType::Permuted_Lower)
        {
          double anorm = 0.;
          double ainvnorm = 0.;

          if (calccond)
            {
              // Calculate the 1-norm of matrix for rcond calculation
              for (octave_idx_type j = 0; j < nr; j++)
                {
                  double atmp = 0.;
                  for (octave_idx_type i = cidx (j); i < cidx (j+1); i++)
                    atmp += std::abs (data (i));
                  if (atmp > anorm)
                    anorm = atmp;
                }
            }

          if (typ == MatrixType::Upper || typ == MatrixType::Lower)
            {
              octave_idx_type nz = nnz ();
              octave_idx_type cx = 0;
              octave_idx_type nz2 = nz;
              retval = SparseComplexMatrix (nr, nc, nz2);

              for (octave_idx_type i = 0; i < nr; i++)
                {
                  octave_quit ();
                  // place the 1 in the identity position
                  octave_idx_type cx_colstart = cx;

                  if (cx == nz2)
                    {
                      nz2 *= 2;
                      retval.change_capacity (nz2);
                    }

                  retval.xcidx (i) = cx;
                  retval.xridx (cx) = i;
                  retval.xdata (cx) = 1.0;
                  cx++;

                  // iterate accross columns of input matrix
                  for (octave_idx_type j = i+1; j < nr; j++)
                    {
                      Complex v = 0.;
                      // iterate to calculate sum
                      octave_idx_type colXp = retval.xcidx (i);
                      octave_idx_type colUp = cidx (j);
                      octave_idx_type rpX, rpU;

                      if (cidx (j) == cidx (j+1))
                        {
                          (*current_liboctave_error_handler)
                            ("division by zero");
                          goto inverse_singular;
                        }

                      do
                        {
                          octave_quit ();
                          rpX = retval.xridx (colXp);
                          rpU = ridx (colUp);

                          if (rpX < rpU)
                            colXp++;
                          else if (rpX > rpU)
                            colUp++;
                          else
                            {
                              v -= retval.xdata (colXp) * data (colUp);
                              colXp++;
                              colUp++;
                            }
                        } while ((rpX<j) && (rpU<j) &&
                                 (colXp<cx) && (colUp<nz));


                      // get A(m,m)
                      if (typ == MatrixType::Upper)
                        colUp = cidx (j+1) - 1;
                      else
                        colUp = cidx (j);
                      Complex pivot = data (colUp);
                      if (pivot == 0. || ridx (colUp) != j)
                        {
                          (*current_liboctave_error_handler)
                            ("division by zero");
                          goto inverse_singular;
                        }

                      if (v != 0.)
                        {
                          if (cx == nz2)
                            {
                              nz2 *= 2;
                              retval.change_capacity (nz2);
                            }

                          retval.xridx (cx) = j;
                          retval.xdata (cx) = v / pivot;
                          cx++;
                        }
                    }

                  // get A(m,m)
                  octave_idx_type colUp;
                  if (typ == MatrixType::Upper)
                    colUp = cidx (i+1) - 1;
                  else
                    colUp = cidx (i);
                  Complex pivot = data (colUp);
                  if (pivot == 0. || ridx (colUp) != i)
                    {
                      (*current_liboctave_error_handler) ("division by zero");
                      goto inverse_singular;
                    }

                  if (pivot != 1.0)
                    for (octave_idx_type j = cx_colstart; j < cx; j++)
                      retval.xdata (j) /= pivot;
                }
              retval.xcidx (nr) = cx;
              retval.maybe_compress ();
            }
          else
            {
              octave_idx_type nz = nnz ();
              octave_idx_type cx = 0;
              octave_idx_type nz2 = nz;
              retval = SparseComplexMatrix (nr, nc, nz2);

              OCTAVE_LOCAL_BUFFER (Complex, work, nr);
              OCTAVE_LOCAL_BUFFER (octave_idx_type, rperm, nr);

              octave_idx_type *perm = mattyp.triangular_perm ();
              if (typ == MatrixType::Permuted_Upper)
                {
                  for (octave_idx_type i = 0; i < nr; i++)
                    rperm[perm[i]] = i;
                }
              else
                {
                  for (octave_idx_type i = 0; i < nr; i++)
                    rperm[i] = perm[i];
                  for (octave_idx_type i = 0; i < nr; i++)
                    perm[rperm[i]] = i;
                }

              for (octave_idx_type i = 0; i < nr; i++)
                {
                  octave_quit ();
                  octave_idx_type iidx = rperm[i];

                  for (octave_idx_type j = 0; j < nr; j++)
                    work[j] = 0.;

                  // place the 1 in the identity position
                  work[iidx] = 1.0;

                  // iterate accross columns of input matrix
                  for (octave_idx_type j = iidx+1; j < nr; j++)
                    {
                      Complex v = 0.;
                      octave_idx_type jidx = perm[j];
                      // iterate to calculate sum
                      for (octave_idx_type k = cidx (jidx);
                           k < cidx (jidx+1); k++)
                        {
                          octave_quit ();
                          v -= work[ridx (k)] * data (k);
                        }

                      // get A(m,m)
                      Complex pivot;
                      if (typ == MatrixType::Permuted_Upper)
                        pivot = data (cidx (jidx+1) - 1);
                      else
                        pivot = data (cidx (jidx));
                      if (pivot == 0.)
                        {
                          (*current_liboctave_error_handler)
                            ("division by zero");
                          goto inverse_singular;
                        }

                      work[j] = v / pivot;
                    }

                  // get A(m,m)
                  octave_idx_type colUp;
                  if (typ == MatrixType::Permuted_Upper)
                    colUp = cidx (perm[iidx]+1) - 1;
                  else
                    colUp = cidx (perm[iidx]);

                  Complex pivot = data (colUp);
                  if (pivot == 0.)
                    {
                      (*current_liboctave_error_handler)
                        ("division by zero");
                      goto inverse_singular;
                    }

                  octave_idx_type new_cx = cx;
                  for (octave_idx_type j = iidx; j < nr; j++)
                    if (work[j] != 0.0)
                      {
                        new_cx++;
                        if (pivot != 1.0)
                          work[j] /= pivot;
                      }

                  if (cx < new_cx)
                    {
                      nz2 = (2*nz2 < new_cx ? new_cx : 2*nz2);
                      retval.change_capacity (nz2);
                    }

                  retval.xcidx (i) = cx;
                  for (octave_idx_type j = iidx; j < nr; j++)
                    if (work[j] != 0.)
                      {
                        retval.xridx (cx) = j;
                        retval.xdata (cx++) = work[j];
                      }
                }

              retval.xcidx (nr) = cx;
              retval.maybe_compress ();
            }

          if (calccond)
            {
              // Calculate the 1-norm of inverse matrix for rcond calculation
              for (octave_idx_type j = 0; j < nr; j++)
                {
                  double atmp = 0.;
                  for (octave_idx_type i = retval.cidx (j);
                       i < retval.cidx (j+1); i++)
                    atmp += std::abs (retval.data (i));
                  if (atmp > ainvnorm)
                    ainvnorm = atmp;
                }

              rcond = 1. / ainvnorm / anorm;
            }
        }
      else
        (*current_liboctave_error_handler) ("incorrect matrix type");
    }

  return retval;

 inverse_singular:
  return SparseComplexMatrix ();
}

SparseComplexMatrix
SparseComplexMatrix::inverse (MatrixType& mattype, octave_idx_type& info,
                              double& rcond, int, int calc_cond) const
{
  int typ = mattype.type (false);
  SparseComplexMatrix ret;

  if (typ == MatrixType::Unknown)
    typ = mattype.type (*this);

  if (typ == MatrixType::Diagonal || typ == MatrixType::Permuted_Diagonal)
    ret = dinverse (mattype, info, rcond, true, calc_cond);
  else if (typ == MatrixType::Upper || typ == MatrixType::Permuted_Upper)
    ret = tinverse (mattype, info, rcond, true, calc_cond).transpose ();
  else if (typ == MatrixType::Lower || typ == MatrixType::Permuted_Lower)
    {
      MatrixType newtype = mattype.transpose ();
      ret = transpose ().tinverse (newtype, info, rcond, true, calc_cond);
    }
  else
    {
      if (mattype.is_hermitian ())
        {
          MatrixType tmp_typ (MatrixType::Upper);
          SparseComplexCHOL fact (*this, info, false);
          rcond = fact.rcond ();
          if (info == 0)
            {
              double rcond2;
              SparseMatrix Q = fact.Q ();
              SparseComplexMatrix InvL = fact.L ().transpose ().
                tinverse (tmp_typ, info, rcond2, true, false);
              ret = Q * InvL.hermitian () * InvL * Q.transpose ();
            }
          else
            {
              // Matrix is either singular or not positive definite
              mattype.mark_as_unsymmetric ();
              typ = MatrixType::Full;
            }
        }

      if (!mattype.is_hermitian ())
        {
          octave_idx_type n = rows ();
          ColumnVector Qinit(n);
          for (octave_idx_type i = 0; i < n; i++)
            Qinit(i) = i;

          MatrixType tmp_typ (MatrixType::Upper);
          SparseComplexLU fact (*this, Qinit, Matrix (), false, false);
          rcond = fact.rcond ();
          double rcond2;
          SparseComplexMatrix InvL = fact.L ().transpose ().
            tinverse (tmp_typ, info, rcond2, true, false);
          SparseComplexMatrix InvU = fact.U ().
            tinverse (tmp_typ, info, rcond2, true, false).transpose ();
          ret = fact.Pc ().transpose () * InvU * InvL * fact.Pr ();
        }
    }

  return ret;
}

ComplexDET
SparseComplexMatrix::determinant (void) const
{
  octave_idx_type info;
  double rcond;
  return determinant (info, rcond, 0);
}

ComplexDET
SparseComplexMatrix::determinant (octave_idx_type& info) const
{
  double rcond;
  return determinant (info, rcond, 0);
}

ComplexDET
SparseComplexMatrix::determinant (octave_idx_type& err, double& rcond, int) const
{
  ComplexDET retval;
#ifdef HAVE_UMFPACK

  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();

  if (nr == 0 || nc == 0 || nr != nc)
    {
      retval = ComplexDET (1.0);
    }
  else
    {
      err = 0;

      // Setup the control parameters
      Matrix Control (UMFPACK_CONTROL, 1);
      double *control = Control.fortran_vec ();
      UMFPACK_ZNAME (defaults) (control);

      double tmp = octave_sparse_params::get_key ("spumoni");
      if (!xisnan (tmp))
        Control (UMFPACK_PRL) = tmp;

      tmp = octave_sparse_params::get_key ("piv_tol");
      if (!xisnan (tmp))
        {
          Control (UMFPACK_SYM_PIVOT_TOLERANCE) = tmp;
          Control (UMFPACK_PIVOT_TOLERANCE) = tmp;
        }

      // Set whether we are allowed to modify Q or not
      tmp = octave_sparse_params::get_key ("autoamd");
      if (!xisnan (tmp))
        Control (UMFPACK_FIXQ) = tmp;

      // Turn-off UMFPACK scaling for LU
      Control (UMFPACK_SCALE) = UMFPACK_SCALE_NONE;

      UMFPACK_ZNAME (report_control) (control);

      const octave_idx_type *Ap = cidx ();
      const octave_idx_type *Ai = ridx ();
      const Complex *Ax = data ();

      UMFPACK_ZNAME (report_matrix) (nr, nc, Ap, Ai,
                                     reinterpret_cast<const double *> (Ax),
                                     0, 1, control);

      void *Symbolic;
      Matrix Info (1, UMFPACK_INFO);
      double *info = Info.fortran_vec ();
      int status = UMFPACK_ZNAME (qsymbolic)
        (nr, nc, Ap, Ai, reinterpret_cast<const double *> (Ax), 0,
         0, &Symbolic, control, info);

      if (status < 0)
        {
          (*current_liboctave_error_handler)
            ("SparseComplexMatrix::determinant symbolic factorization failed");

          UMFPACK_ZNAME (report_status) (control, status);
          UMFPACK_ZNAME (report_info) (control, info);

          UMFPACK_ZNAME (free_symbolic) (&Symbolic) ;
        }
      else
        {
          UMFPACK_ZNAME (report_symbolic) (Symbolic, control);

          void *Numeric;
          status
            = UMFPACK_ZNAME (numeric) (Ap, Ai,
                                       reinterpret_cast<const double *> (Ax),
                                       0, Symbolic, &Numeric, control, info) ;
          UMFPACK_ZNAME (free_symbolic) (&Symbolic) ;

          rcond = Info (UMFPACK_RCOND);

          if (status < 0)
            {
              (*current_liboctave_error_handler)
                ("SparseComplexMatrix::determinant numeric factorization failed");

              UMFPACK_ZNAME (report_status) (control, status);
              UMFPACK_ZNAME (report_info) (control, info);

              UMFPACK_ZNAME (free_numeric) (&Numeric);
            }
          else
            {
              UMFPACK_ZNAME (report_numeric) (Numeric, control);

              double c10[2], e10;

              status = UMFPACK_ZNAME (get_determinant) (c10, 0, &e10,
                                                        Numeric, info);

              if (status < 0)
                {
                  (*current_liboctave_error_handler)
                    ("SparseComplexMatrix::determinant error calculating determinant");

                  UMFPACK_ZNAME (report_status) (control, status);
                  UMFPACK_ZNAME (report_info) (control, info);
                }
              else
                retval = ComplexDET (Complex (c10[0], c10[1]), e10, 10);

              UMFPACK_ZNAME (free_numeric) (&Numeric);
            }
        }
    }
#else
  (*current_liboctave_error_handler) ("UMFPACK not installed");
#endif

  return retval;
}

ComplexMatrix
SparseComplexMatrix::dsolve (MatrixType &mattype, const Matrix& b,
                             octave_idx_type& err, double& rcond,
                             solve_singularity_handler, bool calc_cond) const
{
  ComplexMatrix retval;

  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();
  octave_idx_type nm = (nc < nr ? nc : nr);
  err = 0;

  if (nr != b.rows ())
    (*current_liboctave_error_handler)
      ("matrix dimension mismatch solution of linear equations");
  else if (nr == 0 || nc == 0 || b.cols () == 0)
    retval = ComplexMatrix (nc, b.cols (), Complex (0.0, 0.0));
  else
    {
      // Print spparms("spumoni") info if requested
      int typ = mattype.type ();
      mattype.info ();

      if (typ == MatrixType::Diagonal ||
          typ == MatrixType::Permuted_Diagonal)
        {
          retval.resize (nc, b.cols (), Complex (0.,0.));
          if (typ == MatrixType::Diagonal)
            for (octave_idx_type j = 0; j < b.cols (); j++)
                for (octave_idx_type i = 0; i < nm; i++)
                  retval(i,j) = b(i,j) / data (i);
          else
            for (octave_idx_type j = 0; j < b.cols (); j++)
              for (octave_idx_type k = 0; k < nc; k++)
                for (octave_idx_type i = cidx (k); i < cidx (k+1); i++)
                  retval(k,j) = b(ridx (i),j) / data (i);

          if (calc_cond)
            {
              double dmax = 0., dmin = octave_Inf;
              for (octave_idx_type i = 0; i < nm; i++)
                {
                  double tmp = std::abs (data (i));
                  if (tmp > dmax)
                    dmax = tmp;
                  if (tmp < dmin)
                    dmin = tmp;
                }
              rcond = dmin / dmax;
            }
          else
            rcond = 1.0;
        }
      else
        (*current_liboctave_error_handler) ("incorrect matrix type");
    }

  return retval;
}

SparseComplexMatrix
SparseComplexMatrix::dsolve (MatrixType &mattype, const SparseMatrix& b,
                             octave_idx_type& err, double& rcond,
                             solve_singularity_handler,
                             bool calc_cond) const
{
  SparseComplexMatrix retval;

  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();
  octave_idx_type nm = (nc < nr ? nc : nr);
  err = 0;

  if (nr != b.rows ())
    (*current_liboctave_error_handler)
      ("matrix dimension mismatch solution of linear equations");
  else if (nr == 0 || nc == 0 || b.cols () == 0)
    retval = SparseComplexMatrix (nc, b.cols ());
  else
    {
      // Print spparms("spumoni") info if requested
      int typ = mattype.type ();
      mattype.info ();

      if (typ == MatrixType::Diagonal ||
          typ == MatrixType::Permuted_Diagonal)
        {
          octave_idx_type b_nc = b.cols ();
          octave_idx_type b_nz = b.nnz ();
          retval = SparseComplexMatrix (nc, b_nc, b_nz);

          retval.xcidx (0) = 0;
          octave_idx_type ii = 0;
          if (typ == MatrixType::Diagonal)
            for (octave_idx_type j = 0; j < b.cols (); j++)
              {
                for (octave_idx_type i = b.cidx (j); i < b.cidx (j+1); i++)
                  {
                    if (b.ridx (i) >= nm)
                      break;
                    retval.xridx (ii) = b.ridx (i);
                    retval.xdata (ii++) = b.data (i) / data (b.ridx (i));
                  }
                retval.xcidx (j+1) = ii;
              }
          else
            for (octave_idx_type j = 0; j < b.cols (); j++)
              {
                for (octave_idx_type l = 0; l < nc; l++)
                  for (octave_idx_type i = cidx (l); i < cidx (l+1); i++)
                    {
                      bool found = false;
                      octave_idx_type k;
                      for (k = b.cidx (j); k < b.cidx (j+1); k++)
                        if (ridx (i) == b.ridx (k))
                          {
                            found = true;
                            break;
                          }
                      if (found)
                        {
                          retval.xridx (ii) = l;
                          retval.xdata (ii++) = b.data (k) / data (i);
                        }
                    }
                retval.xcidx (j+1) = ii;
              }

          if (calc_cond)
            {
              double dmax = 0., dmin = octave_Inf;
              for (octave_idx_type i = 0; i < nm; i++)
                {
                  double tmp = std::abs (data (i));
                  if (tmp > dmax)
                    dmax = tmp;
                  if (tmp < dmin)
                    dmin = tmp;
                }
              rcond = dmin / dmax;
            }
          else
            rcond = 1.0;
        }
      else
        (*current_liboctave_error_handler) ("incorrect matrix type");
    }

  return retval;
}

ComplexMatrix
SparseComplexMatrix::dsolve (MatrixType &mattype, const ComplexMatrix& b,
                             octave_idx_type& err, double& rcond,
                             solve_singularity_handler,
                             bool calc_cond) const
{
  ComplexMatrix retval;

  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();
  octave_idx_type nm = (nc < nr ? nc : nr);
  err = 0;

  if (nr != b.rows ())
    (*current_liboctave_error_handler)
      ("matrix dimension mismatch solution of linear equations");
  else if (nr == 0 || nc == 0 || b.cols () == 0)
    retval = ComplexMatrix (nc, b.cols (), Complex (0.0, 0.0));
  else
    {
      // Print spparms("spumoni") info if requested
      int typ = mattype.type ();
      mattype.info ();

      if (typ == MatrixType::Diagonal ||
          typ == MatrixType::Permuted_Diagonal)
        {
          retval.resize (nc, b.cols (), Complex (0.,0.));
          if (typ == MatrixType::Diagonal)
            for (octave_idx_type j = 0; j < b.cols (); j++)
              for (octave_idx_type i = 0; i < nm; i++)
                retval(i,j) = b(i,j) / data (i);
          else
            for (octave_idx_type j = 0; j < b.cols (); j++)
              for (octave_idx_type k = 0; k < nc; k++)
                for (octave_idx_type i = cidx (k); i < cidx (k+1); i++)
                  retval(k,j) = b(ridx (i),j) / data (i);

          if (calc_cond)
            {
              double dmax = 0., dmin = octave_Inf;
              for (octave_idx_type i = 0; i < nr; i++)
                {
                  double tmp = std::abs (data (i));
                  if (tmp > dmax)
                    dmax = tmp;
                  if (tmp < dmin)
                    dmin = tmp;
                }
              rcond = dmin / dmax;
            }
          else
            rcond = 1.0;
        }
      else
        (*current_liboctave_error_handler) ("incorrect matrix type");
    }

  return retval;
}

SparseComplexMatrix
SparseComplexMatrix::dsolve (MatrixType &mattype, const SparseComplexMatrix& b,
                             octave_idx_type& err, double& rcond,
                             solve_singularity_handler,
                             bool calc_cond) const
{
  SparseComplexMatrix retval;

  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();
  octave_idx_type nm = (nc < nr ? nc : nr);
  err = 0;

  if (nr != b.rows ())
    (*current_liboctave_error_handler)
      ("matrix dimension mismatch solution of linear equations");
  else if (nr == 0 || nc == 0 || b.cols () == 0)
    retval = SparseComplexMatrix (nc, b.cols ());
  else
    {
      // Print spparms("spumoni") info if requested
      int typ = mattype.type ();
      mattype.info ();

      if (typ == MatrixType::Diagonal ||
          typ == MatrixType::Permuted_Diagonal)
        {
          octave_idx_type b_nc = b.cols ();
          octave_idx_type b_nz = b.nnz ();
          retval = SparseComplexMatrix (nc, b_nc, b_nz);

          retval.xcidx (0) = 0;
          octave_idx_type ii = 0;
          if (typ == MatrixType::Diagonal)
            for (octave_idx_type j = 0; j < b.cols (); j++)
              {
                for (octave_idx_type i = b.cidx (j); i < b.cidx (j+1); i++)
                  {
                    if (b.ridx (i) >= nm)
                      break;
                    retval.xridx (ii) = b.ridx (i);
                    retval.xdata (ii++) = b.data (i) / data (b.ridx (i));
                  }
                retval.xcidx (j+1) = ii;
              }
          else
            for (octave_idx_type j = 0; j < b.cols (); j++)
              {
                for (octave_idx_type l = 0; l < nc; l++)
                  for (octave_idx_type i = cidx (l); i < cidx (l+1); i++)
                    {
                      bool found = false;
                      octave_idx_type k;
                      for (k = b.cidx (j); k < b.cidx (j+1); k++)
                        if (ridx (i) == b.ridx (k))
                          {
                            found = true;
                            break;
                          }
                      if (found)
                        {
                          retval.xridx (ii) = l;
                          retval.xdata (ii++) = b.data (k) / data (i);
                        }
                    }
                retval.xcidx (j+1) = ii;
              }

          if (calc_cond)
            {
              double dmax = 0., dmin = octave_Inf;
              for (octave_idx_type i = 0; i < nm; i++)
                {
                  double tmp = std::abs (data (i));
                  if (tmp > dmax)
                    dmax = tmp;
                  if (tmp < dmin)
                    dmin = tmp;
                }
              rcond = dmin / dmax;
            }
          else
            rcond = 1.0;
        }
      else
        (*current_liboctave_error_handler) ("incorrect matrix type");
    }

  return retval;
}

ComplexMatrix
SparseComplexMatrix::utsolve (MatrixType &mattype, const Matrix& b,
                              octave_idx_type& err, double& rcond,
                              solve_singularity_handler sing_handler,
                              bool calc_cond) const
{
  ComplexMatrix retval;

  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();
  octave_idx_type nm = (nc > nr ? nc : nr);
  err = 0;

  if (nr != b.rows ())
    (*current_liboctave_error_handler)
      ("matrix dimension mismatch solution of linear equations");
  else if (nr == 0 || nc == 0 || b.cols () == 0)
    retval = ComplexMatrix (nc, b.cols (), Complex (0.0, 0.0));
  else
    {
      // Print spparms("spumoni") info if requested
      int typ = mattype.type ();
      mattype.info ();

      if (typ == MatrixType::Permuted_Upper ||
          typ == MatrixType::Upper)
        {
          double anorm = 0.;
          double ainvnorm = 0.;
          octave_idx_type b_nc = b.cols ();
          rcond = 1.;

          if (calc_cond)
            {
              // Calculate the 1-norm of matrix for rcond calculation
              for (octave_idx_type j = 0; j < nc; j++)
                {
                  double atmp = 0.;
                  for (octave_idx_type i = cidx (j); i < cidx (j+1); i++)
                    atmp += std::abs (data (i));
                  if (atmp > anorm)
                    anorm = atmp;
                }
            }

          if (typ == MatrixType::Permuted_Upper)
            {
              retval.resize (nc, b_nc);
              octave_idx_type *perm = mattype.triangular_perm ();
              OCTAVE_LOCAL_BUFFER (Complex, work, nm);

              for (octave_idx_type j = 0; j < b_nc; j++)
                {
                  for (octave_idx_type i = 0; i < nr; i++)
                    work[i] = b(i,j);
                  for (octave_idx_type i = nr; i < nc; i++)
                    work[i] = 0.;

                  for (octave_idx_type k = nc-1; k >= 0; k--)
                    {
                      octave_idx_type kidx = perm[k];

                      if (work[k] != 0.)
                        {
                          if (ridx (cidx (kidx+1)-1) != k ||
                              data (cidx (kidx+1)-1) == 0.)
                            {
                              err = -2;
                              goto triangular_error;
                            }

                          Complex tmp = work[k] / data (cidx (kidx+1)-1);
                          work[k] = tmp;
                          for (octave_idx_type i = cidx (kidx);
                               i < cidx (kidx+1)-1; i++)
                            {
                              octave_idx_type iidx = ridx (i);
                              work[iidx] = work[iidx] - tmp * data (i);
                            }
                        }
                    }

                  for (octave_idx_type i = 0; i < nc; i++)
                    retval(perm[i], j) = work[i];
                }

              if (calc_cond)
                {
                  // Calculation of 1-norm of inv(*this)
                  for (octave_idx_type i = 0; i < nm; i++)
                    work[i] = 0.;

                  for (octave_idx_type j = 0; j < nr; j++)
                    {
                      work[j] = 1.;

                      for (octave_idx_type k = j; k >= 0; k--)
                        {
                          octave_idx_type iidx = perm[k];

                          if (work[k] != 0.)
                            {
                              Complex tmp = work[k] / data (cidx (iidx+1)-1);
                              work[k] = tmp;
                              for (octave_idx_type i = cidx (iidx);
                                   i < cidx (iidx+1)-1; i++)
                                {
                                  octave_idx_type idx2 = ridx (i);
                                  work[idx2] = work[idx2] - tmp * data (i);
                                }
                            }
                        }
                      double atmp = 0;
                      for (octave_idx_type i = 0; i < j+1; i++)
                        {
                          atmp += std::abs (work[i]);
                          work[i] = 0.;
                        }
                      if (atmp > ainvnorm)
                        ainvnorm = atmp;
                    }
                  rcond = 1. / ainvnorm / anorm;
                }
            }
          else
            {
              OCTAVE_LOCAL_BUFFER (Complex, work, nm);
              retval.resize (nc, b_nc);

              for (octave_idx_type j = 0; j < b_nc; j++)
                {
                  for (octave_idx_type i = 0; i < nr; i++)
                    work[i] = b(i,j);
                  for (octave_idx_type i = nr; i < nc; i++)
                    work[i] = 0.;

                  for (octave_idx_type k = nc-1; k >= 0; k--)
                    {
                      if (work[k] != 0.)
                        {
                          if (ridx (cidx (k+1)-1) != k ||
                              data (cidx (k+1)-1) == 0.)
                            {
                              err = -2;
                              goto triangular_error;
                            }

                          Complex tmp = work[k] / data (cidx (k+1)-1);
                          work[k] = tmp;
                          for (octave_idx_type i = cidx (k); i < cidx (k+1)-1; i++)
                            {
                              octave_idx_type iidx = ridx (i);
                              work[iidx] = work[iidx] - tmp * data (i);
                            }
                        }
                    }

                  for (octave_idx_type i = 0; i < nc; i++)
                    retval.xelem (i, j) = work[i];
                }

              if (calc_cond)
                {
                  // Calculation of 1-norm of inv(*this)
                  for (octave_idx_type i = 0; i < nm; i++)
                    work[i] = 0.;

                  for (octave_idx_type j = 0; j < nr; j++)
                    {
                      work[j] = 1.;

                      for (octave_idx_type k = j; k >= 0; k--)
                        {
                          if (work[k] != 0.)
                            {
                              Complex tmp = work[k] / data (cidx (k+1)-1);
                              work[k] = tmp;
                              for (octave_idx_type i = cidx (k);
                                   i < cidx (k+1)-1; i++)
                                {
                                  octave_idx_type iidx = ridx (i);
                                  work[iidx] = work[iidx] - tmp * data (i);
                                }
                            }
                        }
                      double atmp = 0;
                      for (octave_idx_type i = 0; i < j+1; i++)
                        {
                          atmp += std::abs (work[i]);
                          work[i] = 0.;
                        }
                      if (atmp > ainvnorm)
                        ainvnorm = atmp;
                    }
                  rcond = 1. / ainvnorm / anorm;
                }
            }

        triangular_error:
          if (err != 0)
            {
              if (sing_handler)
                {
                  sing_handler (rcond);
                  mattype.mark_as_rectangular ();
                }
              else
                (*current_liboctave_error_handler)
                  ("SparseComplexMatrix::solve matrix singular to machine precision, rcond = %g",
                   rcond);
            }

          volatile double rcond_plus_one = rcond + 1.0;

          if (rcond_plus_one == 1.0 || xisnan (rcond))
            {
              err = -2;

              if (sing_handler)
                {
                  sing_handler (rcond);
                  mattype.mark_as_rectangular ();
                }
              else
                (*current_liboctave_error_handler)
                  ("matrix singular to machine precision, rcond = %g",
                   rcond);
            }
        }
      else
        (*current_liboctave_error_handler) ("incorrect matrix type");
    }

  return retval;
}

SparseComplexMatrix
SparseComplexMatrix::utsolve (MatrixType &mattype, const SparseMatrix& b,
                              octave_idx_type& err, double& rcond,
                              solve_singularity_handler sing_handler,
                              bool calc_cond) const
{
  SparseComplexMatrix retval;

  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();
  octave_idx_type nm = (nc > nr ? nc : nr);
  err = 0;

  if (nr != b.rows ())
    (*current_liboctave_error_handler)
      ("matrix dimension mismatch solution of linear equations");
  else if (nr == 0 || nc == 0 || b.cols () == 0)
    retval = SparseComplexMatrix (nc, b.cols ());
  else
    {
      // Print spparms("spumoni") info if requested
      int typ = mattype.type ();
      mattype.info ();

      if (typ == MatrixType::Permuted_Upper ||
          typ == MatrixType::Upper)
        {
          double anorm = 0.;
          double ainvnorm = 0.;
          rcond = 1.;

          if (calc_cond)
            {
              // Calculate the 1-norm of matrix for rcond calculation
              for (octave_idx_type j = 0; j < nc; j++)
                {
                  double atmp = 0.;
                  for (octave_idx_type i = cidx (j); i < cidx (j+1); i++)
                    atmp += std::abs (data (i));
                  if (atmp > anorm)
                    anorm = atmp;
                }
            }

          octave_idx_type b_nc = b.cols ();
          octave_idx_type b_nz = b.nnz ();
          retval = SparseComplexMatrix (nc, b_nc, b_nz);
          retval.xcidx (0) = 0;
          octave_idx_type ii = 0;
          octave_idx_type x_nz = b_nz;

          if (typ == MatrixType::Permuted_Upper)
            {
              octave_idx_type *perm = mattype.triangular_perm ();
              OCTAVE_LOCAL_BUFFER (Complex, work, nm);

              OCTAVE_LOCAL_BUFFER (octave_idx_type, rperm, nc);
              for (octave_idx_type i = 0; i < nc; i++)
                rperm[perm[i]] = i;

              for (octave_idx_type j = 0; j < b_nc; j++)
                {
                  for (octave_idx_type i = 0; i < nm; i++)
                    work[i] = 0.;
                  for (octave_idx_type i = b.cidx (j); i < b.cidx (j+1); i++)
                    work[b.ridx (i)] = b.data (i);

                  for (octave_idx_type k = nc-1; k >= 0; k--)
                    {
                      octave_idx_type kidx = perm[k];

                      if (work[k] != 0.)
                        {
                          if (ridx (cidx (kidx+1)-1) != k ||
                              data (cidx (kidx+1)-1) == 0.)
                            {
                              err = -2;
                              goto triangular_error;
                            }

                          Complex tmp = work[k] / data (cidx (kidx+1)-1);
                          work[k] = tmp;
                          for (octave_idx_type i = cidx (kidx);
                               i < cidx (kidx+1)-1; i++)
                            {
                              octave_idx_type iidx = ridx (i);
                              work[iidx] = work[iidx] - tmp * data (i);
                            }
                        }
                    }

                  // Count non-zeros in work vector and adjust space in
                  // retval if needed
                  octave_idx_type new_nnz = 0;
                  for (octave_idx_type i = 0; i < nc; i++)
                    if (work[i] != 0.)
                      new_nnz++;

                  if (ii + new_nnz > x_nz)
                    {
                      // Resize the sparse matrix
                      octave_idx_type sz = new_nnz * (b_nc - j) + x_nz;
                      retval.change_capacity (sz);
                      x_nz = sz;
                    }

                  for (octave_idx_type i = 0; i < nc; i++)
                    if (work[rperm[i]] != 0.)
                      {
                        retval.xridx (ii) = i;
                        retval.xdata (ii++) = work[rperm[i]];
                      }
                  retval.xcidx (j+1) = ii;
                }

              retval.maybe_compress ();

              if (calc_cond)
                {
                  // Calculation of 1-norm of inv(*this)
                  for (octave_idx_type i = 0; i < nm; i++)
                    work[i] = 0.;

                  for (octave_idx_type j = 0; j < nr; j++)
                    {
                      work[j] = 1.;

                      for (octave_idx_type k = j; k >= 0; k--)
                        {
                          octave_idx_type iidx = perm[k];

                          if (work[k] != 0.)
                            {
                              Complex tmp = work[k] / data (cidx (iidx+1)-1);
                              work[k] = tmp;
                              for (octave_idx_type i = cidx (iidx);
                                   i < cidx (iidx+1)-1; i++)
                                {
                                  octave_idx_type idx2 = ridx (i);
                                  work[idx2] = work[idx2] - tmp * data (i);
                                }
                            }
                        }
                      double atmp = 0;
                      for (octave_idx_type i = 0; i < j+1; i++)
                        {
                          atmp += std::abs (work[i]);
                          work[i] = 0.;
                        }
                      if (atmp > ainvnorm)
                        ainvnorm = atmp;
                    }
                  rcond = 1. / ainvnorm / anorm;
                }
            }
          else
            {
              OCTAVE_LOCAL_BUFFER (Complex, work, nm);

              for (octave_idx_type j = 0; j < b_nc; j++)
                {
                  for (octave_idx_type i = 0; i < nm; i++)
                    work[i] = 0.;
                  for (octave_idx_type i = b.cidx (j); i < b.cidx (j+1); i++)
                    work[b.ridx (i)] = b.data (i);

                  for (octave_idx_type k = nc-1; k >= 0; k--)
                    {
                      if (work[k] != 0.)
                        {
                          if (ridx (cidx (k+1)-1) != k ||
                              data (cidx (k+1)-1) == 0.)
                            {
                              err = -2;
                              goto triangular_error;
                            }

                          Complex tmp = work[k] / data (cidx (k+1)-1);
                          work[k] = tmp;
                          for (octave_idx_type i = cidx (k); i < cidx (k+1)-1; i++)
                            {
                              octave_idx_type iidx = ridx (i);
                              work[iidx] = work[iidx] - tmp * data (i);
                            }
                        }
                    }

                  // Count non-zeros in work vector and adjust space in
                  // retval if needed
                  octave_idx_type new_nnz = 0;
                  for (octave_idx_type i = 0; i < nc; i++)
                    if (work[i] != 0.)
                      new_nnz++;

                  if (ii + new_nnz > x_nz)
                    {
                      // Resize the sparse matrix
                      octave_idx_type sz = new_nnz * (b_nc - j) + x_nz;
                      retval.change_capacity (sz);
                      x_nz = sz;
                    }

                  for (octave_idx_type i = 0; i < nc; i++)
                    if (work[i] != 0.)
                      {
                        retval.xridx (ii) = i;
                        retval.xdata (ii++) = work[i];
                      }
                  retval.xcidx (j+1) = ii;
                }

              retval.maybe_compress ();

              if (calc_cond)
                {
                  // Calculation of 1-norm of inv(*this)
                  for (octave_idx_type i = 0; i < nm; i++)
                    work[i] = 0.;

                  for (octave_idx_type j = 0; j < nr; j++)
                    {
                      work[j] = 1.;

                      for (octave_idx_type k = j; k >= 0; k--)
                        {
                          if (work[k] != 0.)
                            {
                              Complex tmp = work[k] / data (cidx (k+1)-1);
                              work[k] = tmp;
                              for (octave_idx_type i = cidx (k);
                                   i < cidx (k+1)-1; i++)
                                {
                                  octave_idx_type iidx = ridx (i);
                                  work[iidx] = work[iidx] - tmp * data (i);
                                }
                            }
                        }
                      double atmp = 0;
                      for (octave_idx_type i = 0; i < j+1; i++)
                        {
                          atmp += std::abs (work[i]);
                          work[i] = 0.;
                        }
                      if (atmp > ainvnorm)
                        ainvnorm = atmp;
                    }
                  rcond = 1. / ainvnorm / anorm;
                }
            }

        triangular_error:
          if (err != 0)
            {
              if (sing_handler)
                {
                  sing_handler (rcond);
                  mattype.mark_as_rectangular ();
                }
              else
                (*current_liboctave_error_handler)
                  ("SparseComplexMatrix::solve matrix singular to machine precision, rcond = %g",
                   rcond);
            }

          volatile double rcond_plus_one = rcond + 1.0;

          if (rcond_plus_one == 1.0 || xisnan (rcond))
            {
              err = -2;

              if (sing_handler)
                {
                  sing_handler (rcond);
                  mattype.mark_as_rectangular ();
                }
              else
                (*current_liboctave_error_handler)
                  ("matrix singular to machine precision, rcond = %g",
                   rcond);
            }
        }
      else
        (*current_liboctave_error_handler) ("incorrect matrix type");
    }
  return retval;
}

ComplexMatrix
SparseComplexMatrix::utsolve (MatrixType &mattype, const ComplexMatrix& b,
                              octave_idx_type& err, double& rcond,
                              solve_singularity_handler sing_handler,
                              bool calc_cond) const
{
  ComplexMatrix retval;

  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();
  octave_idx_type nm = (nc > nr ? nc : nr);
  err = 0;

  if (nr != b.rows ())
    (*current_liboctave_error_handler)
      ("matrix dimension mismatch solution of linear equations");
  else if (nr == 0 || nc == 0 || b.cols () == 0)
    retval = ComplexMatrix (nc, b.cols (), Complex (0.0, 0.0));
  else
    {
      // Print spparms("spumoni") info if requested
      int typ = mattype.type ();
      mattype.info ();

      if (typ == MatrixType::Permuted_Upper ||
          typ == MatrixType::Upper)
        {
          double anorm = 0.;
          double ainvnorm = 0.;
          octave_idx_type b_nc = b.cols ();
          rcond = 1.;

          if (calc_cond)
            {
              // Calculate the 1-norm of matrix for rcond calculation
              for (octave_idx_type j = 0; j < nc; j++)
                {
                  double atmp = 0.;
                  for (octave_idx_type i = cidx (j); i < cidx (j+1); i++)
                    atmp += std::abs (data (i));
                  if (atmp > anorm)
                    anorm = atmp;
                }
            }

          if (typ == MatrixType::Permuted_Upper)
            {
              retval.resize (nc, b_nc);
              octave_idx_type *perm = mattype.triangular_perm ();
              OCTAVE_LOCAL_BUFFER (Complex, work, nm);

              for (octave_idx_type j = 0; j < b_nc; j++)
                {
                  for (octave_idx_type i = 0; i < nr; i++)
                    work[i] = b(i,j);
                  for (octave_idx_type i = nr; i < nc; i++)
                    work[i] = 0.;

                  for (octave_idx_type k = nc-1; k >= 0; k--)
                    {
                      octave_idx_type kidx = perm[k];

                      if (work[k] != 0.)
                        {
                          if (ridx (cidx (kidx+1)-1) != k ||
                              data (cidx (kidx+1)-1) == 0.)
                            {
                              err = -2;
                              goto triangular_error;
                            }

                          Complex tmp = work[k] / data (cidx (kidx+1)-1);
                          work[k] = tmp;
                          for (octave_idx_type i = cidx (kidx);
                               i < cidx (kidx+1)-1; i++)
                            {
                              octave_idx_type iidx = ridx (i);
                              work[iidx] = work[iidx] - tmp * data (i);
                            }
                        }
                    }

                  for (octave_idx_type i = 0; i < nc; i++)
                    retval(perm[i], j) = work[i];
                }

              if (calc_cond)
                {
                  // Calculation of 1-norm of inv(*this)
                  for (octave_idx_type i = 0; i < nm; i++)
                    work[i] = 0.;

                  for (octave_idx_type j = 0; j < nr; j++)
                    {
                      work[j] = 1.;

                      for (octave_idx_type k = j; k >= 0; k--)
                        {
                          octave_idx_type iidx = perm[k];

                          if (work[k] != 0.)
                            {
                              Complex tmp = work[k] / data (cidx (iidx+1)-1);
                              work[k] = tmp;
                              for (octave_idx_type i = cidx (iidx);
                                   i < cidx (iidx+1)-1; i++)
                                {
                                  octave_idx_type idx2 = ridx (i);
                                  work[idx2] = work[idx2] - tmp * data (i);
                                }
                            }
                        }
                      double atmp = 0;
                      for (octave_idx_type i = 0; i < j+1; i++)
                        {
                          atmp += std::abs (work[i]);
                          work[i] = 0.;
                        }
                      if (atmp > ainvnorm)
                        ainvnorm = atmp;
                    }
                  rcond = 1. / ainvnorm / anorm;
                }
            }
          else
            {
              OCTAVE_LOCAL_BUFFER (Complex, work, nm);
              retval.resize (nc, b_nc);

              for (octave_idx_type j = 0; j < b_nc; j++)
                {
                  for (octave_idx_type i = 0; i < nr; i++)
                    work[i] = b(i,j);
                  for (octave_idx_type i = nr; i < nc; i++)
                    work[i] = 0.;

                  for (octave_idx_type k = nc-1; k >= 0; k--)
                    {
                      if (work[k] != 0.)
                        {
                          if (ridx (cidx (k+1)-1) != k ||
                              data (cidx (k+1)-1) == 0.)
                            {
                              err = -2;
                              goto triangular_error;
                            }

                          Complex tmp = work[k] / data (cidx (k+1)-1);
                          work[k] = tmp;
                          for (octave_idx_type i = cidx (k); i < cidx (k+1)-1; i++)
                            {
                              octave_idx_type iidx = ridx (i);
                              work[iidx] = work[iidx] - tmp * data (i);
                            }
                        }
                    }

                  for (octave_idx_type i = 0; i < nc; i++)
                    retval.xelem (i, j) = work[i];
                }

              if (calc_cond)
                {
                  // Calculation of 1-norm of inv(*this)
                  for (octave_idx_type i = 0; i < nm; i++)
                    work[i] = 0.;

                  for (octave_idx_type j = 0; j < nr; j++)
                    {
                      work[j] = 1.;

                      for (octave_idx_type k = j; k >= 0; k--)
                        {
                          if (work[k] != 0.)
                            {
                              Complex tmp = work[k] / data (cidx (k+1)-1);
                              work[k] = tmp;
                              for (octave_idx_type i = cidx (k);
                                   i < cidx (k+1)-1; i++)
                                {
                                  octave_idx_type iidx = ridx (i);
                                  work[iidx] = work[iidx] - tmp * data (i);
                                }
                            }
                        }
                      double atmp = 0;
                      for (octave_idx_type i = 0; i < j+1; i++)
                        {
                          atmp += std::abs (work[i]);
                          work[i] = 0.;
                        }
                      if (atmp > ainvnorm)
                        ainvnorm = atmp;
                    }
                  rcond = 1. / ainvnorm / anorm;
                }
            }

        triangular_error:
          if (err != 0)
            {
              if (sing_handler)
                {
                  sing_handler (rcond);
                  mattype.mark_as_rectangular ();
                }
              else
                (*current_liboctave_error_handler)
                  ("SparseComplexMatrix::solve matrix singular to machine precision, rcond = %g",
                   rcond);
            }

          volatile double rcond_plus_one = rcond + 1.0;

          if (rcond_plus_one == 1.0 || xisnan (rcond))
            {
              err = -2;

              if (sing_handler)
                {
                  sing_handler (rcond);
                  mattype.mark_as_rectangular ();
                }
              else
                (*current_liboctave_error_handler)
                  ("matrix singular to machine precision, rcond = %g",
                   rcond);
            }
        }
      else
        (*current_liboctave_error_handler) ("incorrect matrix type");
    }

  return retval;
}

SparseComplexMatrix
SparseComplexMatrix::utsolve (MatrixType &mattype, const SparseComplexMatrix& b,
                              octave_idx_type& err, double& rcond,
                              solve_singularity_handler sing_handler,
                              bool calc_cond) const
{
  SparseComplexMatrix retval;

  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();
  octave_idx_type nm = (nc > nr ? nc : nr);
  err = 0;

  if (nr != b.rows ())
    (*current_liboctave_error_handler)
      ("matrix dimension mismatch solution of linear equations");
  else if (nr == 0 || nc == 0 || b.cols () == 0)
    retval = SparseComplexMatrix (nc, b.cols ());
  else
    {
      // Print spparms("spumoni") info if requested
      int typ = mattype.type ();
      mattype.info ();

      if (typ == MatrixType::Permuted_Upper ||
          typ == MatrixType::Upper)
        {
          double anorm = 0.;
          double ainvnorm = 0.;
          rcond = 1.;

          if (calc_cond)
            {
              // Calculate the 1-norm of matrix for rcond calculation
              for (octave_idx_type j = 0; j < nc; j++)
                {
                  double atmp = 0.;
                  for (octave_idx_type i = cidx (j); i < cidx (j+1); i++)
                    atmp += std::abs (data (i));
                  if (atmp > anorm)
                    anorm = atmp;
                }
            }

          octave_idx_type b_nc = b.cols ();
          octave_idx_type b_nz = b.nnz ();
          retval = SparseComplexMatrix (nc, b_nc, b_nz);
          retval.xcidx (0) = 0;
          octave_idx_type ii = 0;
          octave_idx_type x_nz = b_nz;

          if (typ == MatrixType::Permuted_Upper)
            {
              octave_idx_type *perm = mattype.triangular_perm ();
              OCTAVE_LOCAL_BUFFER (Complex, work, nm);

              OCTAVE_LOCAL_BUFFER (octave_idx_type, rperm, nc);
              for (octave_idx_type i = 0; i < nc; i++)
                rperm[perm[i]] = i;

              for (octave_idx_type j = 0; j < b_nc; j++)
                {
                  for (octave_idx_type i = 0; i < nm; i++)
                    work[i] = 0.;
                  for (octave_idx_type i = b.cidx (j); i < b.cidx (j+1); i++)
                    work[b.ridx (i)] = b.data (i);

                  for (octave_idx_type k = nc-1; k >= 0; k--)
                    {
                      octave_idx_type kidx = perm[k];

                      if (work[k] != 0.)
                        {
                          if (ridx (cidx (kidx+1)-1) != k ||
                              data (cidx (kidx+1)-1) == 0.)
                            {
                              err = -2;
                              goto triangular_error;
                            }

                          Complex tmp = work[k] / data (cidx (kidx+1)-1);
                          work[k] = tmp;
                          for (octave_idx_type i = cidx (kidx);
                               i < cidx (kidx+1)-1; i++)
                            {
                              octave_idx_type iidx = ridx (i);
                              work[iidx] = work[iidx] - tmp * data (i);
                            }
                        }
                    }

                  // Count non-zeros in work vector and adjust space in
                  // retval if needed
                  octave_idx_type new_nnz = 0;
                  for (octave_idx_type i = 0; i < nc; i++)
                    if (work[i] != 0.)
                      new_nnz++;

                  if (ii + new_nnz > x_nz)
                    {
                      // Resize the sparse matrix
                      octave_idx_type sz = new_nnz * (b_nc - j) + x_nz;
                      retval.change_capacity (sz);
                      x_nz = sz;
                    }

                  for (octave_idx_type i = 0; i < nc; i++)
                    if (work[rperm[i]] != 0.)
                      {
                        retval.xridx (ii) = i;
                        retval.xdata (ii++) = work[rperm[i]];
                      }
                  retval.xcidx (j+1) = ii;
                }

              retval.maybe_compress ();

              if (calc_cond)
                {
                  // Calculation of 1-norm of inv(*this)
                  for (octave_idx_type i = 0; i < nm; i++)
                    work[i] = 0.;

                  for (octave_idx_type j = 0; j < nr; j++)
                    {
                      work[j] = 1.;

                      for (octave_idx_type k = j; k >= 0; k--)
                        {
                          octave_idx_type iidx = perm[k];

                          if (work[k] != 0.)
                            {
                              Complex tmp = work[k] / data (cidx (iidx+1)-1);
                              work[k] = tmp;
                              for (octave_idx_type i = cidx (iidx);
                                   i < cidx (iidx+1)-1; i++)
                                {
                                  octave_idx_type idx2 = ridx (i);
                                  work[idx2] = work[idx2] - tmp * data (i);
                                }
                            }
                        }
                      double atmp = 0;
                      for (octave_idx_type i = 0; i < j+1; i++)
                        {
                          atmp += std::abs (work[i]);
                          work[i] = 0.;
                        }
                      if (atmp > ainvnorm)
                        ainvnorm = atmp;
                    }
                  rcond = 1. / ainvnorm / anorm;
                }
            }
          else
            {
              OCTAVE_LOCAL_BUFFER (Complex, work, nm);

              for (octave_idx_type j = 0; j < b_nc; j++)
                {
                  for (octave_idx_type i = 0; i < nm; i++)
                    work[i] = 0.;
                  for (octave_idx_type i = b.cidx (j); i < b.cidx (j+1); i++)
                    work[b.ridx (i)] = b.data (i);

                  for (octave_idx_type k = nr-1; k >= 0; k--)
                    {
                      if (work[k] != 0.)
                        {
                          if (ridx (cidx (k+1)-1) != k ||
                              data (cidx (k+1)-1) == 0.)
                            {
                              err = -2;
                              goto triangular_error;
                            }

                          Complex tmp = work[k] / data (cidx (k+1)-1);
                          work[k] = tmp;
                          for (octave_idx_type i = cidx (k); i < cidx (k+1)-1; i++)
                            {
                              octave_idx_type iidx = ridx (i);
                              work[iidx] = work[iidx] - tmp * data (i);
                            }
                        }
                    }

                  // Count non-zeros in work vector and adjust space in
                  // retval if needed
                  octave_idx_type new_nnz = 0;
                  for (octave_idx_type i = 0; i < nc; i++)
                    if (work[i] != 0.)
                      new_nnz++;

                  if (ii + new_nnz > x_nz)
                    {
                      // Resize the sparse matrix
                      octave_idx_type sz = new_nnz * (b_nc - j) + x_nz;
                      retval.change_capacity (sz);
                      x_nz = sz;
                    }

                  for (octave_idx_type i = 0; i < nc; i++)
                    if (work[i] != 0.)
                      {
                        retval.xridx (ii) = i;
                        retval.xdata (ii++) = work[i];
                      }
                  retval.xcidx (j+1) = ii;
                }

              retval.maybe_compress ();

              if (calc_cond)
                {
                  // Calculation of 1-norm of inv(*this)
                  for (octave_idx_type i = 0; i < nm; i++)
                    work[i] = 0.;

                  for (octave_idx_type j = 0; j < nr; j++)
                    {
                      work[j] = 1.;

                      for (octave_idx_type k = j; k >= 0; k--)
                        {
                          if (work[k] != 0.)
                            {
                              Complex tmp = work[k] / data (cidx (k+1)-1);
                              work[k] = tmp;
                              for (octave_idx_type i = cidx (k);
                                   i < cidx (k+1)-1; i++)
                                {
                                  octave_idx_type iidx = ridx (i);
                                  work[iidx] = work[iidx] - tmp * data (i);
                                }
                            }
                        }
                      double atmp = 0;
                      for (octave_idx_type i = 0; i < j+1; i++)
                        {
                          atmp += std::abs (work[i]);
                          work[i] = 0.;
                        }
                      if (atmp > ainvnorm)
                        ainvnorm = atmp;
                    }
                  rcond = 1. / ainvnorm / anorm;
                }
            }

        triangular_error:
          if (err != 0)
            {
              if (sing_handler)
                {
                  sing_handler (rcond);
                  mattype.mark_as_rectangular ();
                }
              else
                (*current_liboctave_error_handler)
                  ("SparseComplexMatrix::solve matrix singular to machine precision, rcond = %g",
                   rcond);
            }

          volatile double rcond_plus_one = rcond + 1.0;

          if (rcond_plus_one == 1.0 || xisnan (rcond))
            {
              err = -2;

              if (sing_handler)
                {
                  sing_handler (rcond);
                  mattype.mark_as_rectangular ();
                }
              else
                (*current_liboctave_error_handler)
                  ("matrix singular to machine precision, rcond = %g",
                   rcond);
            }
        }
      else
        (*current_liboctave_error_handler) ("incorrect matrix type");
    }

  return retval;
}

ComplexMatrix
SparseComplexMatrix::ltsolve (MatrixType &mattype, const Matrix& b,
                              octave_idx_type& err, double& rcond,
                              solve_singularity_handler sing_handler,
                              bool calc_cond) const
{
  ComplexMatrix retval;

  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();
  octave_idx_type nm = (nc > nr ? nc : nr);
  err = 0;

  if (nr != b.rows ())
    (*current_liboctave_error_handler)
      ("matrix dimension mismatch solution of linear equations");
  else if (nr == 0 || nc == 0 || b.cols () == 0)
    retval = ComplexMatrix (nc, b.cols (), Complex (0.0, 0.0));
  else
    {
      // Print spparms("spumoni") info if requested
      int typ = mattype.type ();
      mattype.info ();

      if (typ == MatrixType::Permuted_Lower ||
          typ == MatrixType::Lower)
        {
          double anorm = 0.;
          double ainvnorm = 0.;
          octave_idx_type b_nc = b.cols ();
          rcond = 1.;

          if (calc_cond)
            {
              // Calculate the 1-norm of matrix for rcond calculation
              for (octave_idx_type j = 0; j < nc; j++)
                {
                  double atmp = 0.;
                  for (octave_idx_type i = cidx (j); i < cidx (j+1); i++)
                    atmp += std::abs (data (i));
                  if (atmp > anorm)
                    anorm = atmp;
                }
            }

          if (typ == MatrixType::Permuted_Lower)
            {
              retval.resize (nc, b_nc);
              OCTAVE_LOCAL_BUFFER (Complex, work, nm);
              octave_idx_type *perm = mattype.triangular_perm ();

              for (octave_idx_type j = 0; j < b_nc; j++)
                {
                  for (octave_idx_type i = 0; i < nm; i++)
                    work[i] = 0.;
                  for (octave_idx_type i = 0; i < nr; i++)
                    work[perm[i]] = b(i,j);

                  for (octave_idx_type k = 0; k < nc; k++)
                    {
                      if (work[k] != 0.)
                        {
                          octave_idx_type minr = nr;
                          octave_idx_type mini = 0;

                          for (octave_idx_type i = cidx (k); i < cidx (k+1); i++)
                            if (perm[ridx (i)] < minr)
                              {
                                minr = perm[ridx (i)];
                                mini = i;
                              }

                          if (minr != k || data (mini) == 0.)
                            {
                              err = -2;
                              goto triangular_error;
                            }

                          Complex tmp = work[k] / data (mini);
                          work[k] = tmp;
                          for (octave_idx_type i = cidx (k); i < cidx (k+1); i++)
                            {
                              if (i == mini)
                                continue;

                              octave_idx_type iidx = perm[ridx (i)];
                              work[iidx] = work[iidx] - tmp * data (i);
                            }
                        }
                    }

                  for (octave_idx_type i = 0; i < nc; i++)
                    retval(i, j) = work[i];
                }

              if (calc_cond)
                {
                  // Calculation of 1-norm of inv(*this)
                  for (octave_idx_type i = 0; i < nm; i++)
                    work[i] = 0.;

                  for (octave_idx_type j = 0; j < nr; j++)
                    {
                      work[j] = 1.;

                      for (octave_idx_type k = 0; k < nc; k++)
                        {
                          if (work[k] != 0.)
                            {
                              octave_idx_type minr = nr;
                              octave_idx_type mini = 0;

                              for (octave_idx_type i = cidx (k);
                                   i < cidx (k+1); i++)
                                if (perm[ridx (i)] < minr)
                                  {
                                    minr = perm[ridx (i)];
                                    mini = i;
                                  }

                              Complex tmp = work[k] / data (mini);
                              work[k] = tmp;
                              for (octave_idx_type i = cidx (k);
                                   i < cidx (k+1); i++)
                                {
                                  if (i == mini)
                                    continue;

                                  octave_idx_type iidx = perm[ridx (i)];
                                  work[iidx] = work[iidx] - tmp * data (i);
                                }
                            }
                        }

                      double atmp = 0;
                      for (octave_idx_type i = j; i < nc; i++)
                        {
                          atmp += std::abs (work[i]);
                          work[i] = 0.;
                        }
                      if (atmp > ainvnorm)
                        ainvnorm = atmp;
                    }
                  rcond = 1. / ainvnorm / anorm;
                }
            }
          else
            {
              OCTAVE_LOCAL_BUFFER (Complex, work, nm);
              retval.resize (nc, b_nc, 0.);

              for (octave_idx_type j = 0; j < b_nc; j++)
                {
                  for (octave_idx_type i = 0; i < nr; i++)
                    work[i] = b(i,j);
                  for (octave_idx_type i = nr; i < nc; i++)
                    work[i] = 0.;
                  for (octave_idx_type k = 0; k < nc; k++)
                    {
                      if (work[k] != 0.)
                        {
                          if (ridx (cidx (k)) != k ||
                              data (cidx (k)) == 0.)
                            {
                              err = -2;
                              goto triangular_error;
                            }

                          Complex tmp = work[k] / data (cidx (k));
                          work[k] = tmp;
                          for (octave_idx_type i = cidx (k)+1; i < cidx (k+1); i++)
                            {
                              octave_idx_type iidx = ridx (i);
                              work[iidx] = work[iidx] - tmp * data (i);
                            }
                        }
                    }
                  for (octave_idx_type i = 0; i < nc; i++)
                    retval.xelem (i, j) = work[i];
                }

              if (calc_cond)
                {
                  // Calculation of 1-norm of inv(*this)
                  for (octave_idx_type i = 0; i < nm; i++)
                    work[i] = 0.;

                  for (octave_idx_type j = 0; j < nr; j++)
                    {
                      work[j] = 1.;

                      for (octave_idx_type k = j; k < nc; k++)
                        {

                          if (work[k] != 0.)
                            {
                              Complex tmp = work[k] / data (cidx (k));
                              work[k] = tmp;
                              for (octave_idx_type i = cidx (k)+1;
                                   i < cidx (k+1); i++)
                                {
                                  octave_idx_type iidx = ridx (i);
                                  work[iidx] = work[iidx] - tmp * data (i);
                                }
                            }
                        }
                      double atmp = 0;
                      for (octave_idx_type i = j; i < nc; i++)
                        {
                          atmp += std::abs (work[i]);
                          work[i] = 0.;
                        }
                      if (atmp > ainvnorm)
                        ainvnorm = atmp;
                    }
                  rcond = 1. / ainvnorm / anorm;
                }
            }
        triangular_error:
          if (err != 0)
            {
              if (sing_handler)
                {
                  sing_handler (rcond);
                  mattype.mark_as_rectangular ();
                }
              else
                (*current_liboctave_error_handler)
                  ("SparseComplexMatrix::solve matrix singular to machine precision, rcond = %g",
                   rcond);
            }

          volatile double rcond_plus_one = rcond + 1.0;

          if (rcond_plus_one == 1.0 || xisnan (rcond))
            {
              err = -2;

              if (sing_handler)
                {
                  sing_handler (rcond);
                  mattype.mark_as_rectangular ();
                }
              else
                (*current_liboctave_error_handler)
                  ("matrix singular to machine precision, rcond = %g",
                   rcond);
            }
        }
      else
        (*current_liboctave_error_handler) ("incorrect matrix type");
    }

  return retval;
}

SparseComplexMatrix
SparseComplexMatrix::ltsolve (MatrixType &mattype, const SparseMatrix& b,
                              octave_idx_type& err, double& rcond,
                              solve_singularity_handler sing_handler,
                              bool calc_cond) const
{
  SparseComplexMatrix retval;

  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();
  octave_idx_type nm = (nc > nr ? nc : nr);

  err = 0;

  if (nr != b.rows ())
    (*current_liboctave_error_handler)
      ("matrix dimension mismatch solution of linear equations");
  else if (nr == 0 || nc == 0 || b.cols () == 0)
    retval = SparseComplexMatrix (nc, b.cols ());
  else
    {
      // Print spparms("spumoni") info if requested
      int typ = mattype.type ();
      mattype.info ();

      if (typ == MatrixType::Permuted_Lower ||
          typ == MatrixType::Lower)
        {
          double anorm = 0.;
          double ainvnorm = 0.;
          rcond = 1.;

          if (calc_cond)
            {
              // Calculate the 1-norm of matrix for rcond calculation
              for (octave_idx_type j = 0; j < nc; j++)
                {
                  double atmp = 0.;
                  for (octave_idx_type i = cidx (j); i < cidx (j+1); i++)
                    atmp += std::abs (data (i));
                  if (atmp > anorm)
                    anorm = atmp;
                }
            }

          octave_idx_type b_nc = b.cols ();
          octave_idx_type b_nz = b.nnz ();
          retval = SparseComplexMatrix (nc, b_nc, b_nz);
          retval.xcidx (0) = 0;
          octave_idx_type ii = 0;
          octave_idx_type x_nz = b_nz;

          if (typ == MatrixType::Permuted_Lower)
            {
              OCTAVE_LOCAL_BUFFER (Complex, work, nm);
              octave_idx_type *perm = mattype.triangular_perm ();

              for (octave_idx_type j = 0; j < b_nc; j++)
                {
                  for (octave_idx_type i = 0; i < nm; i++)
                    work[i] = 0.;
                  for (octave_idx_type i = b.cidx (j); i < b.cidx (j+1); i++)
                    work[perm[b.ridx (i)]] = b.data (i);

                  for (octave_idx_type k = 0; k < nc; k++)
                    {
                      if (work[k] != 0.)
                        {
                          octave_idx_type minr = nr;
                          octave_idx_type mini = 0;

                          for (octave_idx_type i = cidx (k); i < cidx (k+1); i++)
                            if (perm[ridx (i)] < minr)
                              {
                                minr = perm[ridx (i)];
                                mini = i;
                              }

                          if (minr != k || data (mini) == 0.)
                            {
                              err = -2;
                              goto triangular_error;
                            }

                          Complex tmp = work[k] / data (mini);
                          work[k] = tmp;
                          for (octave_idx_type i = cidx (k); i < cidx (k+1); i++)
                            {
                              if (i == mini)
                                continue;

                              octave_idx_type iidx = perm[ridx (i)];
                              work[iidx] = work[iidx] - tmp * data (i);
                            }
                        }
                    }

                  // Count non-zeros in work vector and adjust space in
                  // retval if needed
                  octave_idx_type new_nnz = 0;
                  for (octave_idx_type i = 0; i < nc; i++)
                    if (work[i] != 0.)
                      new_nnz++;

                  if (ii + new_nnz > x_nz)
                    {
                      // Resize the sparse matrix
                      octave_idx_type sz = new_nnz * (b_nc - j) + x_nz;
                      retval.change_capacity (sz);
                      x_nz = sz;
                    }

                  for (octave_idx_type i = 0; i < nc; i++)
                    if (work[i] != 0.)
                      {
                        retval.xridx (ii) = i;
                        retval.xdata (ii++) = work[i];
                      }
                  retval.xcidx (j+1) = ii;
                }

              retval.maybe_compress ();

              if (calc_cond)
                {
                  // Calculation of 1-norm of inv(*this)
                  for (octave_idx_type i = 0; i < nm; i++)
                    work[i] = 0.;

                  for (octave_idx_type j = 0; j < nr; j++)
                    {
                      work[j] = 1.;

                      for (octave_idx_type k = 0; k < nc; k++)
                        {
                          if (work[k] != 0.)
                            {
                              octave_idx_type minr = nr;
                              octave_idx_type mini = 0;

                              for (octave_idx_type i = cidx (k);
                                   i < cidx (k+1); i++)
                                if (perm[ridx (i)] < minr)
                                  {
                                    minr = perm[ridx (i)];
                                    mini = i;
                                  }

                              Complex tmp = work[k] / data (mini);
                              work[k] = tmp;
                              for (octave_idx_type i = cidx (k);
                                   i < cidx (k+1); i++)
                                {
                                  if (i == mini)
                                    continue;

                                  octave_idx_type iidx = perm[ridx (i)];
                                  work[iidx] = work[iidx] - tmp * data (i);
                                }
                            }
                        }

                      double atmp = 0;
                      for (octave_idx_type i = j; i < nc; i++)
                        {
                          atmp += std::abs (work[i]);
                          work[i] = 0.;
                        }
                      if (atmp > ainvnorm)
                        ainvnorm = atmp;
                    }
                  rcond = 1. / ainvnorm / anorm;
                }
            }
          else
            {
              OCTAVE_LOCAL_BUFFER (Complex, work, nm);

              for (octave_idx_type j = 0; j < b_nc; j++)
                {
                  for (octave_idx_type i = 0; i < nm; i++)
                    work[i] = 0.;
                  for (octave_idx_type i = b.cidx (j); i < b.cidx (j+1); i++)
                    work[b.ridx (i)] = b.data (i);

                  for (octave_idx_type k = 0; k < nc; k++)
                    {
                      if (work[k] != 0.)
                        {
                          if (ridx (cidx (k)) != k ||
                              data (cidx (k)) == 0.)
                            {
                              err = -2;
                              goto triangular_error;
                            }

                          Complex tmp = work[k] / data (cidx (k));
                          work[k] = tmp;
                          for (octave_idx_type i = cidx (k)+1; i < cidx (k+1); i++)
                            {
                              octave_idx_type iidx = ridx (i);
                              work[iidx] = work[iidx] - tmp * data (i);
                            }
                        }
                    }

                  // Count non-zeros in work vector and adjust space in
                  // retval if needed
                  octave_idx_type new_nnz = 0;
                  for (octave_idx_type i = 0; i < nc; i++)
                    if (work[i] != 0.)
                      new_nnz++;

                  if (ii + new_nnz > x_nz)
                    {
                      // Resize the sparse matrix
                      octave_idx_type sz = new_nnz * (b_nc - j) + x_nz;
                      retval.change_capacity (sz);
                      x_nz = sz;
                    }

                  for (octave_idx_type i = 0; i < nc; i++)
                    if (work[i] != 0.)
                      {
                        retval.xridx (ii) = i;
                        retval.xdata (ii++) = work[i];
                      }
                  retval.xcidx (j+1) = ii;
                }

              retval.maybe_compress ();

              if (calc_cond)
                {
                  // Calculation of 1-norm of inv(*this)
                  for (octave_idx_type i = 0; i < nm; i++)
                    work[i] = 0.;

                  for (octave_idx_type j = 0; j < nr; j++)
                    {
                      work[j] = 1.;

                      for (octave_idx_type k = j; k < nc; k++)
                        {

                          if (work[k] != 0.)
                            {
                              Complex tmp = work[k] / data (cidx (k));
                              work[k] = tmp;
                              for (octave_idx_type i = cidx (k)+1;
                                   i < cidx (k+1); i++)
                                {
                                  octave_idx_type iidx = ridx (i);
                                  work[iidx] = work[iidx] - tmp * data (i);
                                }
                            }
                        }
                      double atmp = 0;
                      for (octave_idx_type i = j; i < nc; i++)
                        {
                          atmp += std::abs (work[i]);
                          work[i] = 0.;
                        }
                      if (atmp > ainvnorm)
                        ainvnorm = atmp;
                    }
                  rcond = 1. / ainvnorm / anorm;
                }
            }

        triangular_error:
          if (err != 0)
            {
              if (sing_handler)
                {
                  sing_handler (rcond);
                  mattype.mark_as_rectangular ();
                }
              else
                (*current_liboctave_error_handler)
                  ("SparseComplexMatrix::solve matrix singular to machine precision, rcond = %g",
                   rcond);
            }

          volatile double rcond_plus_one = rcond + 1.0;

          if (rcond_plus_one == 1.0 || xisnan (rcond))
            {
              err = -2;

              if (sing_handler)
                {
                  sing_handler (rcond);
                  mattype.mark_as_rectangular ();
                }
              else
                (*current_liboctave_error_handler)
                  ("matrix singular to machine precision, rcond = %g",
                   rcond);
            }
        }
      else
        (*current_liboctave_error_handler) ("incorrect matrix type");
    }

  return retval;
}

ComplexMatrix
SparseComplexMatrix::ltsolve (MatrixType &mattype, const ComplexMatrix& b,
                              octave_idx_type& err, double& rcond,
                              solve_singularity_handler sing_handler,
                              bool calc_cond) const
{
  ComplexMatrix retval;

  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();
  octave_idx_type nm = (nc > nr ? nc : nr);
  err = 0;

  if (nr != b.rows ())
    (*current_liboctave_error_handler)
      ("matrix dimension mismatch solution of linear equations");
  else if (nr == 0 || nc == 0 || b.cols () == 0)
    retval = ComplexMatrix (nc, b.cols (), Complex (0.0, 0.0));
  else
    {
      // Print spparms("spumoni") info if requested
      int typ = mattype.type ();
      mattype.info ();

      if (typ == MatrixType::Permuted_Lower ||
          typ == MatrixType::Lower)
        {
          double anorm = 0.;
          double ainvnorm = 0.;
          octave_idx_type b_nc = b.cols ();
          rcond = 1.;

          if (calc_cond)
            {
              // Calculate the 1-norm of matrix for rcond calculation
              for (octave_idx_type j = 0; j < nc; j++)
                {
                  double atmp = 0.;
                  for (octave_idx_type i = cidx (j); i < cidx (j+1); i++)
                    atmp += std::abs (data (i));
                  if (atmp > anorm)
                    anorm = atmp;
                }
            }

          if (typ == MatrixType::Permuted_Lower)
            {
              retval.resize (nc, b_nc);
              OCTAVE_LOCAL_BUFFER (Complex, work, nm);
              octave_idx_type *perm = mattype.triangular_perm ();

              for (octave_idx_type j = 0; j < b_nc; j++)
                {
                  for (octave_idx_type i = 0; i < nm; i++)
                    work[i] = 0.;
                  for (octave_idx_type i = 0; i < nr; i++)
                    work[perm[i]] = b(i,j);

                  for (octave_idx_type k = 0; k < nc; k++)
                    {
                      if (work[k] != 0.)
                        {
                          octave_idx_type minr = nr;
                          octave_idx_type mini = 0;

                          for (octave_idx_type i = cidx (k); i < cidx (k+1); i++)
                            if (perm[ridx (i)] < minr)
                              {
                                minr = perm[ridx (i)];
                                mini = i;
                              }

                          if (minr != k || data (mini) == 0.)
                            {
                              err = -2;
                              goto triangular_error;
                            }

                          Complex tmp = work[k] / data (mini);
                          work[k] = tmp;
                          for (octave_idx_type i = cidx (k); i < cidx (k+1); i++)
                            {
                              if (i == mini)
                                continue;

                              octave_idx_type iidx = perm[ridx (i)];
                              work[iidx] = work[iidx] - tmp * data (i);
                            }
                        }
                    }

                  for (octave_idx_type i = 0; i < nc; i++)
                    retval(i, j) = work[i];
                }

              if (calc_cond)
                {
                  // Calculation of 1-norm of inv(*this)
                  for (octave_idx_type i = 0; i < nm; i++)
                    work[i] = 0.;

                  for (octave_idx_type j = 0; j < nr; j++)
                    {
                      work[j] = 1.;

                      for (octave_idx_type k = 0; k < nc; k++)
                        {
                          if (work[k] != 0.)
                            {
                              octave_idx_type minr = nr;
                              octave_idx_type mini = 0;

                              for (octave_idx_type i = cidx (k);
                                   i < cidx (k+1); i++)
                                if (perm[ridx (i)] < minr)
                                  {
                                    minr = perm[ridx (i)];
                                    mini = i;
                                  }

                              Complex tmp = work[k] / data (mini);
                              work[k] = tmp;
                              for (octave_idx_type i = cidx (k);
                                   i < cidx (k+1); i++)
                                {
                                  if (i == mini)
                                    continue;

                                  octave_idx_type iidx = perm[ridx (i)];
                                  work[iidx] = work[iidx] - tmp * data (i);
                                }
                            }
                        }

                      double atmp = 0;
                      for (octave_idx_type i = j; i < nc; i++)
                        {
                          atmp += std::abs (work[i]);
                          work[i] = 0.;
                        }
                      if (atmp > ainvnorm)
                        ainvnorm = atmp;
                    }
                  rcond = 1. / ainvnorm / anorm;
                }
            }
          else
            {
              OCTAVE_LOCAL_BUFFER (Complex, work, nm);
              retval.resize (nc, b_nc, 0.);


              for (octave_idx_type j = 0; j < b_nc; j++)
                {
                  for (octave_idx_type i = 0; i < nr; i++)
                    work[i] = b(i,j);
                  for (octave_idx_type i = nr; i < nc; i++)
                    work[i] = 0.;

                  for (octave_idx_type k = 0; k < nc; k++)
                    {
                      if (work[k] != 0.)
                        {
                          if (ridx (cidx (k)) != k ||
                              data (cidx (k)) == 0.)
                            {
                              err = -2;
                              goto triangular_error;
                            }

                          Complex tmp = work[k] / data (cidx (k));
                          work[k] = tmp;
                          for (octave_idx_type i = cidx (k)+1; i < cidx (k+1); i++)
                            {
                              octave_idx_type iidx = ridx (i);
                              work[iidx] = work[iidx] - tmp * data (i);
                            }
                        }
                    }

                  for (octave_idx_type i = 0; i < nc; i++)
                    retval.xelem (i, j) = work[i];
                }

              if (calc_cond)
                {
                  // Calculation of 1-norm of inv(*this)
                  for (octave_idx_type i = 0; i < nm; i++)
                    work[i] = 0.;

                  for (octave_idx_type j = 0; j < nr; j++)
                    {
                      work[j] = 1.;

                      for (octave_idx_type k = j; k < nc; k++)
                        {

                          if (work[k] != 0.)
                            {
                              Complex tmp = work[k] / data (cidx (k));
                              work[k] = tmp;
                              for (octave_idx_type i = cidx (k)+1;
                                   i < cidx (k+1); i++)
                                {
                                  octave_idx_type iidx = ridx (i);
                                  work[iidx] = work[iidx] - tmp * data (i);
                                }
                            }
                        }
                      double atmp = 0;
                      for (octave_idx_type i = j; i < nc; i++)
                        {
                          atmp += std::abs (work[i]);
                          work[i] = 0.;
                        }
                      if (atmp > ainvnorm)
                        ainvnorm = atmp;
                    }
                  rcond = 1. / ainvnorm / anorm;
                }
            }

        triangular_error:
          if (err != 0)
            {
              if (sing_handler)
                {
                  sing_handler (rcond);
                  mattype.mark_as_rectangular ();
                }
              else
                (*current_liboctave_error_handler)
                  ("SparseComplexMatrix::solve matrix singular to machine precision, rcond = %g",
                   rcond);
            }

          volatile double rcond_plus_one = rcond + 1.0;

          if (rcond_plus_one == 1.0 || xisnan (rcond))
            {
              err = -2;

              if (sing_handler)
                {
                  sing_handler (rcond);
                  mattype.mark_as_rectangular ();
                }
              else
                (*current_liboctave_error_handler)
                  ("matrix singular to machine precision, rcond = %g",
                   rcond);
            }
        }
      else
        (*current_liboctave_error_handler) ("incorrect matrix type");
    }

  return retval;
}

SparseComplexMatrix
SparseComplexMatrix::ltsolve (MatrixType &mattype, const SparseComplexMatrix& b,
                              octave_idx_type& err, double& rcond,
                              solve_singularity_handler sing_handler,
                              bool calc_cond) const
{
  SparseComplexMatrix retval;

  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();
  octave_idx_type nm = (nc > nr ? nc : nr);
  err = 0;

  if (nr != b.rows ())
    (*current_liboctave_error_handler)
      ("matrix dimension mismatch solution of linear equations");
  else if (nr == 0 || nc == 0 || b.cols () == 0)
    retval = SparseComplexMatrix (nc, b.cols ());
  else
    {
      // Print spparms("spumoni") info if requested
      int typ = mattype.type ();
      mattype.info ();

      if (typ == MatrixType::Permuted_Lower ||
          typ == MatrixType::Lower)
        {
          double anorm = 0.;
          double ainvnorm = 0.;
          rcond = 1.;

          if (calc_cond)
            {
              // Calculate the 1-norm of matrix for rcond calculation
              for (octave_idx_type j = 0; j < nc; j++)
                {
                  double atmp = 0.;
                  for (octave_idx_type i = cidx (j); i < cidx (j+1); i++)
                    atmp += std::abs (data (i));
                  if (atmp > anorm)
                    anorm = atmp;
                }
            }

          octave_idx_type b_nc = b.cols ();
          octave_idx_type b_nz = b.nnz ();
          retval = SparseComplexMatrix (nc, b_nc, b_nz);
          retval.xcidx (0) = 0;
          octave_idx_type ii = 0;
          octave_idx_type x_nz = b_nz;

          if (typ == MatrixType::Permuted_Lower)
            {
              OCTAVE_LOCAL_BUFFER (Complex, work, nm);
              octave_idx_type *perm = mattype.triangular_perm ();

              for (octave_idx_type j = 0; j < b_nc; j++)
                {
                  for (octave_idx_type i = 0; i < nm; i++)
                    work[i] = 0.;
                  for (octave_idx_type i = b.cidx (j); i < b.cidx (j+1); i++)
                    work[perm[b.ridx (i)]] = b.data (i);

                  for (octave_idx_type k = 0; k < nc; k++)
                    {
                      if (work[k] != 0.)
                        {
                          octave_idx_type minr = nr;
                          octave_idx_type mini = 0;

                          for (octave_idx_type i = cidx (k); i < cidx (k+1); i++)
                            if (perm[ridx (i)] < minr)
                              {
                                minr = perm[ridx (i)];
                                mini = i;
                              }

                          if (minr != k || data (mini) == 0.)
                            {
                              err = -2;
                              goto triangular_error;
                            }

                          Complex tmp = work[k] / data (mini);
                          work[k] = tmp;
                          for (octave_idx_type i = cidx (k); i < cidx (k+1); i++)
                            {
                              if (i == mini)
                                continue;

                              octave_idx_type iidx = perm[ridx (i)];
                              work[iidx] = work[iidx] - tmp * data (i);
                            }
                        }
                    }

                  // Count non-zeros in work vector and adjust space in
                  // retval if needed
                  octave_idx_type new_nnz = 0;
                  for (octave_idx_type i = 0; i < nc; i++)
                    if (work[i] != 0.)
                      new_nnz++;

                  if (ii + new_nnz > x_nz)
                    {
                      // Resize the sparse matrix
                      octave_idx_type sz = new_nnz * (b_nc - j) + x_nz;
                      retval.change_capacity (sz);
                      x_nz = sz;
                    }

                  for (octave_idx_type i = 0; i < nc; i++)
                    if (work[i] != 0.)
                      {
                        retval.xridx (ii) = i;
                        retval.xdata (ii++) = work[i];
                      }
                  retval.xcidx (j+1) = ii;
                }

              retval.maybe_compress ();

              if (calc_cond)
                {
                  // Calculation of 1-norm of inv(*this)
                  for (octave_idx_type i = 0; i < nm; i++)
                    work[i] = 0.;

                  for (octave_idx_type j = 0; j < nr; j++)
                    {
                      work[j] = 1.;

                      for (octave_idx_type k = 0; k < nc; k++)
                        {
                          if (work[k] != 0.)
                            {
                              octave_idx_type minr = nr;
                              octave_idx_type mini = 0;

                              for (octave_idx_type i = cidx (k);
                                   i < cidx (k+1); i++)
                                if (perm[ridx (i)] < minr)
                                  {
                                    minr = perm[ridx (i)];
                                    mini = i;
                                  }

                              Complex tmp = work[k] / data (mini);
                              work[k] = tmp;
                              for (octave_idx_type i = cidx (k);
                                   i < cidx (k+1); i++)
                                {
                                  if (i == mini)
                                    continue;

                                  octave_idx_type iidx = perm[ridx (i)];
                                  work[iidx] = work[iidx] - tmp * data (i);
                                }
                            }
                        }

                      double atmp = 0;
                      for (octave_idx_type i = j; i < nc; i++)
                        {
                          atmp += std::abs (work[i]);
                          work[i] = 0.;
                        }
                      if (atmp > ainvnorm)
                        ainvnorm = atmp;
                    }
                  rcond = 1. / ainvnorm / anorm;
                }
            }
          else
            {
              OCTAVE_LOCAL_BUFFER (Complex, work, nm);

              for (octave_idx_type j = 0; j < b_nc; j++)
                {
                  for (octave_idx_type i = 0; i < nm; i++)
                    work[i] = 0.;
                  for (octave_idx_type i = b.cidx (j); i < b.cidx (j+1); i++)
                    work[b.ridx (i)] = b.data (i);

                  for (octave_idx_type k = 0; k < nc; k++)
                    {
                      if (work[k] != 0.)
                        {
                          if (ridx (cidx (k)) != k ||
                              data (cidx (k)) == 0.)
                            {
                              err = -2;
                              goto triangular_error;
                            }

                          Complex tmp = work[k] / data (cidx (k));
                          work[k] = tmp;
                          for (octave_idx_type i = cidx (k)+1; i < cidx (k+1); i++)
                            {
                              octave_idx_type iidx = ridx (i);
                              work[iidx] = work[iidx] - tmp * data (i);
                            }
                        }
                    }

                  // Count non-zeros in work vector and adjust space in
                  // retval if needed
                  octave_idx_type new_nnz = 0;
                  for (octave_idx_type i = 0; i < nc; i++)
                    if (work[i] != 0.)
                      new_nnz++;

                  if (ii + new_nnz > x_nz)
                    {
                      // Resize the sparse matrix
                      octave_idx_type sz = new_nnz * (b_nc - j) + x_nz;
                      retval.change_capacity (sz);
                      x_nz = sz;
                    }

                  for (octave_idx_type i = 0; i < nc; i++)
                    if (work[i] != 0.)
                      {
                        retval.xridx (ii) = i;
                        retval.xdata (ii++) = work[i];
                      }
                  retval.xcidx (j+1) = ii;
                }

              retval.maybe_compress ();

              if (calc_cond)
                {
                  // Calculation of 1-norm of inv(*this)
                  for (octave_idx_type i = 0; i < nm; i++)
                    work[i] = 0.;

                  for (octave_idx_type j = 0; j < nr; j++)
                    {
                      work[j] = 1.;

                      for (octave_idx_type k = j; k < nc; k++)
                        {

                          if (work[k] != 0.)
                            {
                              Complex tmp = work[k] / data (cidx (k));
                              work[k] = tmp;
                              for (octave_idx_type i = cidx (k)+1;
                                   i < cidx (k+1); i++)
                                {
                                  octave_idx_type iidx = ridx (i);
                                  work[iidx] = work[iidx] - tmp * data (i);
                                }
                            }
                        }
                      double atmp = 0;
                      for (octave_idx_type i = j; i < nc; i++)
                        {
                          atmp += std::abs (work[i]);
                          work[i] = 0.;
                        }
                      if (atmp > ainvnorm)
                        ainvnorm = atmp;
                    }
                  rcond = 1. / ainvnorm / anorm;
                }
            }

        triangular_error:
          if (err != 0)
            {
              if (sing_handler)
                {
                  sing_handler (rcond);
                  mattype.mark_as_rectangular ();
                }
              else
                (*current_liboctave_error_handler)
                  ("SparseComplexMatrix::solve matrix singular to machine precision, rcond = %g",
                   rcond);
            }

          volatile double rcond_plus_one = rcond + 1.0;

          if (rcond_plus_one == 1.0 || xisnan (rcond))
            {
              err = -2;

              if (sing_handler)
                {
                  sing_handler (rcond);
                  mattype.mark_as_rectangular ();
                }
              else
                (*current_liboctave_error_handler)
                  ("matrix singular to machine precision, rcond = %g",
                   rcond);
            }
        }
      else
        (*current_liboctave_error_handler) ("incorrect matrix type");
    }

  return retval;
}

ComplexMatrix
SparseComplexMatrix::trisolve (MatrixType &mattype, const Matrix& b,
                               octave_idx_type& err, double& rcond,
                               solve_singularity_handler sing_handler,
                               bool calc_cond) const
{
  ComplexMatrix retval;

  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();
  err = 0;

  if (nr != nc || nr != b.rows ())
    (*current_liboctave_error_handler)
      ("matrix dimension mismatch solution of linear equations");
  else if (nr == 0 || b.cols () == 0)
    retval = ComplexMatrix (nc, b.cols (), Complex (0.0, 0.0));
  else if (calc_cond)
    (*current_liboctave_error_handler)
      ("calculation of condition number not implemented");
  else
    {
      // Print spparms("spumoni") info if requested
      volatile int typ = mattype.type ();
      mattype.info ();

      if (typ == MatrixType::Tridiagonal_Hermitian)
        {
          OCTAVE_LOCAL_BUFFER (double, D, nr);
          OCTAVE_LOCAL_BUFFER (Complex, DL, nr - 1);

          if (mattype.is_dense ())
            {
              octave_idx_type ii = 0;

              for (octave_idx_type j = 0; j < nc-1; j++)
                {
                  D[j] = std::real (data (ii++));
                  DL[j] = data (ii);
                  ii += 2;
                }
              D[nc-1] = std::real (data (ii));
            }
          else
            {
              D[0] = 0.;
              for (octave_idx_type i = 0; i < nr - 1; i++)
                {
                  D[i+1] = 0.;
                  DL[i] = 0.;
                }

              for (octave_idx_type j = 0; j < nc; j++)
                for (octave_idx_type i = cidx (j); i < cidx (j+1); i++)
                  {
                    if (ridx (i) == j)
                      D[j] = std::real (data (i));
                    else if (ridx (i) == j + 1)
                      DL[j] = data (i);
                  }
            }

          octave_idx_type b_nc = b.cols ();
          retval = ComplexMatrix (b);
          Complex *result = retval.fortran_vec ();

          F77_XFCN (zptsv, ZPTSV, (nr, b_nc, D, DL, result,
                                   b.rows (), err));

          if (err != 0)
            {
              err = 0;
              mattype.mark_as_unsymmetric ();
              typ = MatrixType::Tridiagonal;
            }
          else
            rcond = 1.;
        }

      if (typ == MatrixType::Tridiagonal)
        {
          OCTAVE_LOCAL_BUFFER (Complex, DU, nr - 1);
          OCTAVE_LOCAL_BUFFER (Complex, D, nr);
          OCTAVE_LOCAL_BUFFER (Complex, DL, nr - 1);

          if (mattype.is_dense ())
            {
              octave_idx_type ii = 0;

              for (octave_idx_type j = 0; j < nc-1; j++)
                {
                  D[j] = data (ii++);
                  DL[j] = data (ii++);
                  DU[j] = data (ii++);
                }
              D[nc-1] = data (ii);
            }
          else
            {
              D[0] = 0.;
              for (octave_idx_type i = 0; i < nr - 1; i++)
                {
                  D[i+1] = 0.;
                  DL[i] = 0.;
                  DU[i] = 0.;
                }

              for (octave_idx_type j = 0; j < nc; j++)
                for (octave_idx_type i = cidx (j); i < cidx (j+1); i++)
                  {
                    if (ridx (i) == j)
                      D[j] = data (i);
                    else if (ridx (i) == j + 1)
                      DL[j] = data (i);
                    else if (ridx (i) == j - 1)
                      DU[j-1] = data (i);
                  }
            }

          octave_idx_type b_nc = b.cols ();
          retval = ComplexMatrix (b);
          Complex *result = retval.fortran_vec ();

          F77_XFCN (zgtsv, ZGTSV, (nr, b_nc, DL, D, DU, result,
                                   b.rows (), err));

          if (err != 0)
            {
              rcond = 0.;
              err = -2;

              if (sing_handler)
                {
                  sing_handler (rcond);
                  mattype.mark_as_rectangular ();
                }
              else
                (*current_liboctave_error_handler)
                  ("matrix singular to machine precision");

            }
          else
            rcond = 1.;
        }
      else if (typ != MatrixType::Tridiagonal_Hermitian)
               (*current_liboctave_error_handler) ("incorrect matrix type");
    }

  return retval;
}

SparseComplexMatrix
SparseComplexMatrix::trisolve (MatrixType &mattype, const SparseMatrix& b,
                               octave_idx_type& err, double& rcond,
                               solve_singularity_handler sing_handler,
                               bool calc_cond) const
{
  SparseComplexMatrix retval;

  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();
  err = 0;

  if (nr != nc || nr != b.rows ())
    (*current_liboctave_error_handler)
      ("matrix dimension mismatch solution of linear equations");
  else if (nr == 0 || b.cols () == 0)
    retval = SparseComplexMatrix (nc, b.cols ());
  else if (calc_cond)
    (*current_liboctave_error_handler)
      ("calculation of condition number not implemented");
  else
    {
      // Print spparms("spumoni") info if requested
      int typ = mattype.type ();
      mattype.info ();

      // Note can't treat symmetric case as there is no dpttrf function
      if (typ == MatrixType::Tridiagonal ||
          typ == MatrixType::Tridiagonal_Hermitian)
        {
          OCTAVE_LOCAL_BUFFER (Complex, DU2, nr - 2);
          OCTAVE_LOCAL_BUFFER (Complex, DU, nr - 1);
          OCTAVE_LOCAL_BUFFER (Complex, D, nr);
          OCTAVE_LOCAL_BUFFER (Complex, DL, nr - 1);
          Array<octave_idx_type> ipvt (dim_vector (nr, 1));
          octave_idx_type *pipvt = ipvt.fortran_vec ();

          if (mattype.is_dense ())
            {
              octave_idx_type ii = 0;

              for (octave_idx_type j = 0; j < nc-1; j++)
                {
                  D[j] = data (ii++);
                  DL[j] = data (ii++);
                  DU[j] = data (ii++);
                }
              D[nc-1] = data (ii);
            }
          else
            {
              D[0] = 0.;
              for (octave_idx_type i = 0; i < nr - 1; i++)
                {
                  D[i+1] = 0.;
                  DL[i] = 0.;
                  DU[i] = 0.;
                }

              for (octave_idx_type j = 0; j < nc; j++)
                for (octave_idx_type i = cidx (j); i < cidx (j+1); i++)
                  {
                    if (ridx (i) == j)
                      D[j] = data (i);
                    else if (ridx (i) == j + 1)
                      DL[j] = data (i);
                    else if (ridx (i) == j - 1)
                      DU[j-1] = data (i);
                  }
            }

          F77_XFCN (zgttrf, ZGTTRF, (nr, DL, D, DU, DU2, pipvt, err));

          if (err != 0)
            {
              err = -2;
              rcond = 0.0;

              if (sing_handler)
                {
                  sing_handler (rcond);
                  mattype.mark_as_rectangular ();
                }
              else
                (*current_liboctave_error_handler)
                  ("matrix singular to machine precision");

            }
          else
            {
              char job = 'N';
              volatile octave_idx_type x_nz = b.nnz ();
              octave_idx_type b_nc = b.cols ();
              retval = SparseComplexMatrix (nr, b_nc, x_nz);
              retval.xcidx (0) = 0;
              volatile octave_idx_type ii = 0;
              rcond = 1.0;

              OCTAVE_LOCAL_BUFFER (Complex, work, nr);

              for (volatile octave_idx_type j = 0; j < b_nc; j++)
                {
                  for (octave_idx_type i = 0; i < nr; i++)
                    work[i] = 0.;
                  for (octave_idx_type i = b.cidx (j); i < b.cidx (j+1); i++)
                    work[b.ridx (i)] = b.data (i);

                  F77_XFCN (zgttrs, ZGTTRS,
                            (F77_CONST_CHAR_ARG2 (&job, 1),
                             nr, 1, DL, D, DU, DU2, pipvt,
                             work, b.rows (), err
                             F77_CHAR_ARG_LEN (1)));

                  // Count non-zeros in work vector and adjust
                  // space in retval if needed
                  octave_idx_type new_nnz = 0;
                  for (octave_idx_type i = 0; i < nr; i++)
                    if (work[i] != 0.)
                      new_nnz++;

                  if (ii + new_nnz > x_nz)
                    {
                      // Resize the sparse matrix
                      octave_idx_type sz = new_nnz * (b_nc - j) + x_nz;
                      retval.change_capacity (sz);
                      x_nz = sz;
                    }

                  for (octave_idx_type i = 0; i < nr; i++)
                    if (work[i] != 0.)
                      {
                        retval.xridx (ii) = i;
                        retval.xdata (ii++) = work[i];
                      }
                  retval.xcidx (j+1) = ii;
                }

              retval.maybe_compress ();
            }
        }
      else if (typ != MatrixType::Tridiagonal_Hermitian)
        (*current_liboctave_error_handler) ("incorrect matrix type");
    }

  return retval;
}

ComplexMatrix
SparseComplexMatrix::trisolve (MatrixType &mattype, const ComplexMatrix& b,
                               octave_idx_type& err, double& rcond,
                               solve_singularity_handler sing_handler,
                               bool calc_cond) const
{
  ComplexMatrix retval;

  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();
  err = 0;

  if (nr != nc || nr != b.rows ())
    (*current_liboctave_error_handler)
      ("matrix dimension mismatch solution of linear equations");
  else if (nr == 0 || b.cols () == 0)
    retval = ComplexMatrix (nc, b.cols (), Complex (0.0, 0.0));
  else if (calc_cond)
    (*current_liboctave_error_handler)
      ("calculation of condition number not implemented");
  else
    {
      // Print spparms("spumoni") info if requested
      volatile int typ = mattype.type ();
      mattype.info ();

      if (typ == MatrixType::Tridiagonal_Hermitian)
        {
          OCTAVE_LOCAL_BUFFER (double, D, nr);
          OCTAVE_LOCAL_BUFFER (Complex, DL, nr - 1);

          if (mattype.is_dense ())
            {
              octave_idx_type ii = 0;

              for (octave_idx_type j = 0; j < nc-1; j++)
                {
                  D[j] = std::real (data (ii++));
                  DL[j] = data (ii);
                  ii += 2;
                }
              D[nc-1] = std::real (data (ii));
            }
          else
            {
              D[0] = 0.;
              for (octave_idx_type i = 0; i < nr - 1; i++)
                {
                  D[i+1] = 0.;
                  DL[i] = 0.;
                }

              for (octave_idx_type j = 0; j < nc; j++)
                for (octave_idx_type i = cidx (j); i < cidx (j+1); i++)
                  {
                    if (ridx (i) == j)
                      D[j] = std::real (data (i));
                    else if (ridx (i) == j + 1)
                      DL[j] = data (i);
                  }
            }

          octave_idx_type b_nr = b.rows ();
          octave_idx_type b_nc = b.cols ();
          rcond = 1.;

          retval = ComplexMatrix (b);
          Complex *result = retval.fortran_vec ();

          F77_XFCN (zptsv, ZPTSV, (nr, b_nc, D, DL, result,
                                   b_nr, err));

          if (err != 0)
            {
              err = 0;
              mattype.mark_as_unsymmetric ();
              typ = MatrixType::Tridiagonal;
            }
        }

      if (typ == MatrixType::Tridiagonal)
        {
          OCTAVE_LOCAL_BUFFER (Complex, DU, nr - 1);
          OCTAVE_LOCAL_BUFFER (Complex, D, nr);
          OCTAVE_LOCAL_BUFFER (Complex, DL, nr - 1);

          if (mattype.is_dense ())
            {
              octave_idx_type ii = 0;

              for (octave_idx_type j = 0; j < nc-1; j++)
                {
                  D[j] = data (ii++);
                  DL[j] = data (ii++);
                  DU[j] = data (ii++);
                }
              D[nc-1] = data (ii);
            }
          else
            {
              D[0] = 0.;
              for (octave_idx_type i = 0; i < nr - 1; i++)
                {
                  D[i+1] = 0.;
                  DL[i] = 0.;
                  DU[i] = 0.;
                }

              for (octave_idx_type j = 0; j < nc; j++)
                for (octave_idx_type i = cidx (j); i < cidx (j+1); i++)
                  {
                    if (ridx (i) == j)
                      D[j] = data (i);
                    else if (ridx (i) == j + 1)
                      DL[j] = data (i);
                    else if (ridx (i) == j - 1)
                      DU[j-1] = data (i);
                  }
            }

          octave_idx_type b_nr = b.rows ();
          octave_idx_type b_nc = b.cols ();
          rcond = 1.;

          retval = ComplexMatrix (b);
          Complex *result = retval.fortran_vec ();

          F77_XFCN (zgtsv, ZGTSV, (nr, b_nc, DL, D, DU, result,
                                   b_nr, err));

          if (err != 0)
            {
              rcond = 0.;
              err = -2;

              if (sing_handler)
                {
                  sing_handler (rcond);
                  mattype.mark_as_rectangular ();
                }
              else
                (*current_liboctave_error_handler)
                  ("matrix singular to machine precision");
            }
        }
      else if (typ != MatrixType::Tridiagonal_Hermitian)
        (*current_liboctave_error_handler) ("incorrect matrix type");
    }

  return retval;
}

SparseComplexMatrix
SparseComplexMatrix::trisolve (MatrixType &mattype,
                               const SparseComplexMatrix& b,
                               octave_idx_type& err, double& rcond,
                               solve_singularity_handler sing_handler,
                               bool calc_cond) const
{
  SparseComplexMatrix retval;

  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();
  err = 0;

  if (nr != nc || nr != b.rows ())
    (*current_liboctave_error_handler)
      ("matrix dimension mismatch solution of linear equations");
  else if (nr == 0 || b.cols () == 0)
    retval = SparseComplexMatrix (nc, b.cols ());
  else if (calc_cond)
    (*current_liboctave_error_handler)
      ("calculation of condition number not implemented");
  else
    {
      // Print spparms("spumoni") info if requested
      int typ = mattype.type ();
      mattype.info ();

      // Note can't treat symmetric case as there is no dpttrf function
      if (typ == MatrixType::Tridiagonal ||
          typ == MatrixType::Tridiagonal_Hermitian)
        {
          OCTAVE_LOCAL_BUFFER (Complex, DU2, nr - 2);
          OCTAVE_LOCAL_BUFFER (Complex, DU, nr - 1);
          OCTAVE_LOCAL_BUFFER (Complex, D, nr);
          OCTAVE_LOCAL_BUFFER (Complex, DL, nr - 1);
          Array<octave_idx_type> ipvt (dim_vector (nr, 1));
          octave_idx_type *pipvt = ipvt.fortran_vec ();

          if (mattype.is_dense ())
            {
              octave_idx_type ii = 0;

              for (octave_idx_type j = 0; j < nc-1; j++)
                {
                  D[j] = data (ii++);
                  DL[j] = data (ii++);
                  DU[j] = data (ii++);
                }
              D[nc-1] = data (ii);
            }
          else
            {
              D[0] = 0.;
              for (octave_idx_type i = 0; i < nr - 1; i++)
                {
                  D[i+1] = 0.;
                  DL[i] = 0.;
                  DU[i] = 0.;
                }

              for (octave_idx_type j = 0; j < nc; j++)
                for (octave_idx_type i = cidx (j); i < cidx (j+1); i++)
                  {
                    if (ridx (i) == j)
                      D[j] = data (i);
                    else if (ridx (i) == j + 1)
                      DL[j] = data (i);
                    else if (ridx (i) == j - 1)
                      DU[j-1] = data (i);
                  }
            }

          F77_XFCN (zgttrf, ZGTTRF, (nr, DL, D, DU, DU2, pipvt, err));

          if (err != 0)
            {
              rcond = 0.0;
              err = -2;

              if (sing_handler)
                {
                  sing_handler (rcond);
                  mattype.mark_as_rectangular ();
                }
              else
                (*current_liboctave_error_handler)
                  ("matrix singular to machine precision");
            }
          else
            {
              rcond = 1.;
              char job = 'N';
              octave_idx_type b_nr = b.rows ();
              octave_idx_type b_nc = b.cols ();
              OCTAVE_LOCAL_BUFFER (Complex, Bx, b_nr);

              // Take a first guess that the number of non-zero terms
              // will be as many as in b
              volatile octave_idx_type x_nz = b.nnz ();
              volatile octave_idx_type ii = 0;
              retval = SparseComplexMatrix (b_nr, b_nc, x_nz);

              retval.xcidx (0) = 0;
              for (volatile octave_idx_type j = 0; j < b_nc; j++)
                {

                  for (octave_idx_type i = 0; i < b_nr; i++)
                    Bx[i] = b (i,j);

                  F77_XFCN (zgttrs, ZGTTRS,
                            (F77_CONST_CHAR_ARG2 (&job, 1),
                             nr, 1, DL, D, DU, DU2, pipvt,
                             Bx, b_nr, err
                             F77_CHAR_ARG_LEN (1)));

                  if (err != 0)
                    {
                      (*current_liboctave_error_handler)
                        ("SparseComplexMatrix::solve solve failed");

                      err = -1;
                      break;
                    }

                  // Count non-zeros in work vector and adjust
                  // space in retval if needed
                  octave_idx_type new_nnz = 0;
                  for (octave_idx_type i = 0; i < nr; i++)
                    if (Bx[i] != 0.)
                      new_nnz++;

                  if (ii + new_nnz > x_nz)
                    {
                      // Resize the sparse matrix
                      octave_idx_type sz = new_nnz * (b_nc - j) + x_nz;
                      retval.change_capacity (sz);
                      x_nz = sz;
                    }

                  for (octave_idx_type i = 0; i < nr; i++)
                    if (Bx[i] != 0.)
                      {
                        retval.xridx (ii) = i;
                        retval.xdata (ii++) = Bx[i];
                      }

                  retval.xcidx (j+1) = ii;
                }

              retval.maybe_compress ();
            }
        }
      else if (typ != MatrixType::Tridiagonal_Hermitian)
        (*current_liboctave_error_handler) ("incorrect matrix type");
    }

  return retval;
}

ComplexMatrix
SparseComplexMatrix::bsolve (MatrixType &mattype, const Matrix& b,
                             octave_idx_type& err, double& rcond,
                             solve_singularity_handler sing_handler,
                             bool calc_cond) const
{
  ComplexMatrix retval;

  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();
  err = 0;

  if (nr != nc || nr != b.rows ())
    (*current_liboctave_error_handler)
      ("matrix dimension mismatch solution of linear equations");
  else if (nr == 0 || b.cols () == 0)
    retval = ComplexMatrix (nc, b.cols (), Complex (0.0, 0.0));
  else
    {
      // Print spparms("spumoni") info if requested
      volatile int typ = mattype.type ();
      mattype.info ();

      if (typ == MatrixType::Banded_Hermitian)
        {
          octave_idx_type n_lower = mattype.nlower ();
          octave_idx_type ldm = n_lower + 1;
          ComplexMatrix m_band (ldm, nc);
          Complex *tmp_data = m_band.fortran_vec ();

          if (! mattype.is_dense ())
            {
              octave_idx_type ii = 0;

              for (octave_idx_type j = 0; j < ldm; j++)
                for (octave_idx_type i = 0; i < nc; i++)
                  tmp_data[ii++] = 0.;
            }

          for (octave_idx_type j = 0; j < nc; j++)
            for (octave_idx_type i = cidx (j); i < cidx (j+1); i++)
              {
                octave_idx_type ri = ridx (i);
                if (ri >= j)
                  m_band(ri - j, j) = data (i);
              }

          // Calculate the norm of the matrix, for later use.
          double anorm;
          if (calc_cond)
            anorm = m_band.abs ().sum ().row (0).max ();

          char job = 'L';
          F77_XFCN (zpbtrf, ZPBTRF, (F77_CONST_CHAR_ARG2 (&job, 1),
                                     nr, n_lower, tmp_data, ldm, err
                                     F77_CHAR_ARG_LEN (1)));

          if (err != 0)
            {
              rcond = 0.0;
              // Matrix is not positive definite!! Fall through to
              // unsymmetric banded solver.
              mattype.mark_as_unsymmetric ();
              typ = MatrixType::Banded;
              err = 0;
            }
          else
            {
              if (calc_cond)
                {
                  Array<Complex> z (dim_vector (2 * nr, 1));
                  Complex *pz = z.fortran_vec ();
                  Array<double> iz (dim_vector (nr, 1));
                  double *piz = iz.fortran_vec ();

                  F77_XFCN (zpbcon, ZPBCON,
                    (F77_CONST_CHAR_ARG2 (&job, 1),
                     nr, n_lower, tmp_data, ldm,
                     anorm, rcond, pz, piz, err
                     F77_CHAR_ARG_LEN (1)));

                  if (err != 0)
                    err = -2;

                  volatile double rcond_plus_one = rcond + 1.0;

                  if (rcond_plus_one == 1.0 || xisnan (rcond))
                    {
                      err = -2;

                      if (sing_handler)
                        {
                          sing_handler (rcond);
                          mattype.mark_as_rectangular ();
                        }
                      else
                        (*current_liboctave_error_handler)
                          ("matrix singular to machine precision, rcond = %g",
                           rcond);
                    }
                }
              else
                rcond = 1.0;

              if (err == 0)
                {
                  retval = ComplexMatrix (b);
                  Complex *result = retval.fortran_vec ();

                  octave_idx_type b_nc = b.cols ();

                  F77_XFCN (zpbtrs, ZPBTRS,
                            (F77_CONST_CHAR_ARG2 (&job, 1),
                             nr, n_lower, b_nc, tmp_data,
                             ldm, result, b.rows (), err
                             F77_CHAR_ARG_LEN (1)));

                  if (err != 0)
                    {
                      (*current_liboctave_error_handler)
                        ("SparseMatrix::solve solve failed");
                      err = -1;
                    }
                }
            }
        }

      if (typ == MatrixType::Banded)
        {
          // Create the storage for the banded form of the sparse matrix
          octave_idx_type n_upper = mattype.nupper ();
          octave_idx_type n_lower = mattype.nlower ();
          octave_idx_type ldm = n_upper + 2 * n_lower + 1;

          ComplexMatrix m_band (ldm, nc);
          Complex *tmp_data = m_band.fortran_vec ();

          if (! mattype.is_dense ())
            {
              octave_idx_type ii = 0;

              for (octave_idx_type j = 0; j < ldm; j++)
                for (octave_idx_type i = 0; i < nc; i++)
                  tmp_data[ii++] = 0.;
            }

          for (octave_idx_type j = 0; j < nc; j++)
            for (octave_idx_type i = cidx (j); i < cidx (j+1); i++)
              m_band(ridx (i) - j + n_lower + n_upper, j) = data (i);

          // Calculate the norm of the matrix, for later use.
          double anorm;
          if (calc_cond)
            {
              for (octave_idx_type j = 0; j < nr; j++)
                {
                  double atmp = 0.;
                  for (octave_idx_type i = cidx (j); i < cidx (j+1); i++)
                    atmp += std::abs (data (i));
                  if (atmp > anorm)
                    anorm = atmp;
                }
            }

          Array<octave_idx_type> ipvt (dim_vector (nr, 1));
          octave_idx_type *pipvt = ipvt.fortran_vec ();

          F77_XFCN (zgbtrf, ZGBTRF, (nr, nc, n_lower, n_upper, tmp_data,
                                     ldm, pipvt, err));

          // Throw-away extra info LAPACK gives so as to not
          // change output.
          if (err != 0)
            {
              rcond = 0.0;
              err = -2;

              if (sing_handler)
                {
                  sing_handler (rcond);
                  mattype.mark_as_rectangular ();
                }
              else
                (*current_liboctave_error_handler)
                  ("matrix singular to machine precision");
            }
          else
            {
              if (calc_cond)
                {
                  char job = '1';
                  Array<Complex> z (dim_vector (2 * nr, 1));
                  Complex *pz = z.fortran_vec ();
                  Array<double> iz (dim_vector (nr, 1));
                  double *piz = iz.fortran_vec ();

                  F77_XFCN (zgbcon, ZGBCON,
                    (F77_CONST_CHAR_ARG2 (&job, 1),
                     nc, n_lower, n_upper, tmp_data, ldm, pipvt,
                     anorm, rcond, pz, piz, err
                     F77_CHAR_ARG_LEN (1)));

                   if (err != 0)
                    err = -2;

                  volatile double rcond_plus_one = rcond + 1.0;

                  if (rcond_plus_one == 1.0 || xisnan (rcond))
                    {
                      err = -2;

                      if (sing_handler)
                        {
                          sing_handler (rcond);
                          mattype.mark_as_rectangular ();
                        }
                      else
                        (*current_liboctave_error_handler)
                          ("matrix singular to machine precision, rcond = %g",
                           rcond);
                    }
                }
              else
                rcond = 1.;

              if (err == 0)
                {
                  retval = ComplexMatrix (b);
                  Complex *result = retval.fortran_vec ();

                  octave_idx_type b_nc = b.cols ();

                  char job = 'N';
                  F77_XFCN (zgbtrs, ZGBTRS,
                            (F77_CONST_CHAR_ARG2 (&job, 1),
                             nr, n_lower, n_upper, b_nc, tmp_data,
                             ldm, pipvt, result, b.rows (), err
                             F77_CHAR_ARG_LEN (1)));
                }
            }
        }
      else if (typ != MatrixType::Banded_Hermitian)
        (*current_liboctave_error_handler) ("incorrect matrix type");
    }

  return retval;
}

SparseComplexMatrix
SparseComplexMatrix::bsolve (MatrixType &mattype, const SparseMatrix& b,
                             octave_idx_type& err, double& rcond,
                             solve_singularity_handler sing_handler,
                             bool calc_cond) const
{
  SparseComplexMatrix retval;

  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();
  err = 0;

  if (nr != nc || nr != b.rows ())
    (*current_liboctave_error_handler)
      ("matrix dimension mismatch solution of linear equations");
  else if (nr == 0 || b.cols () == 0)
    retval = SparseComplexMatrix (nc, b.cols ());
  else
    {
      // Print spparms("spumoni") info if requested
      volatile int typ = mattype.type ();
      mattype.info ();

      if (typ == MatrixType::Banded_Hermitian)
        {
          octave_idx_type n_lower = mattype.nlower ();
          octave_idx_type ldm = n_lower + 1;

          ComplexMatrix m_band (ldm, nc);
          Complex *tmp_data = m_band.fortran_vec ();

          if (! mattype.is_dense ())
            {
              octave_idx_type ii = 0;

              for (octave_idx_type j = 0; j < ldm; j++)
                for (octave_idx_type i = 0; i < nc; i++)
                  tmp_data[ii++] = 0.;
            }

          for (octave_idx_type j = 0; j < nc; j++)
            for (octave_idx_type i = cidx (j); i < cidx (j+1); i++)
              {
                octave_idx_type ri = ridx (i);
                if (ri >= j)
                  m_band(ri - j, j) = data (i);
              }

          // Calculate the norm of the matrix, for later use.
          double anorm;
          if (calc_cond)
            anorm = m_band.abs ().sum ().row (0).max ();

          char job = 'L';
          F77_XFCN (zpbtrf, ZPBTRF, (F77_CONST_CHAR_ARG2 (&job, 1),
                                     nr, n_lower, tmp_data, ldm, err
                                     F77_CHAR_ARG_LEN (1)));

          if (err != 0)
            {
              rcond = 0.0;
              mattype.mark_as_unsymmetric ();
              typ = MatrixType::Banded;
              err = 0;
            }
          else
            {
              if (calc_cond)
                {
                  Array<Complex> z (dim_vector (2 * nr, 1));
                  Complex *pz = z.fortran_vec ();
                  Array<double> iz (dim_vector (nr, 1));
                  double *piz = iz.fortran_vec ();

                  F77_XFCN (zpbcon, ZPBCON,
                    (F77_CONST_CHAR_ARG2 (&job, 1),
                     nr, n_lower, tmp_data, ldm,
                     anorm, rcond, pz, piz, err
                     F77_CHAR_ARG_LEN (1)));

                  if (err != 0)
                    err = -2;

                  volatile double rcond_plus_one = rcond + 1.0;

                  if (rcond_plus_one == 1.0 || xisnan (rcond))
                    {
                      err = -2;

                      if (sing_handler)
                        {
                          sing_handler (rcond);
                          mattype.mark_as_rectangular ();
                        }
                      else
                        (*current_liboctave_error_handler)
                          ("matrix singular to machine precision, rcond = %g",
                           rcond);
                    }
                }
              else
                rcond = 1.0;

              if (err == 0)
                {
                  octave_idx_type b_nr = b.rows ();
                  octave_idx_type b_nc = b.cols ();
                  OCTAVE_LOCAL_BUFFER (Complex, Bx, b_nr);

                  // Take a first guess that the number of non-zero terms
                  // will be as many as in b
                  volatile octave_idx_type x_nz = b.nnz ();
                  volatile octave_idx_type ii = 0;
                  retval = SparseComplexMatrix (b_nr, b_nc, x_nz);

                  retval.xcidx (0) = 0;
                  for (volatile octave_idx_type j = 0; j < b_nc; j++)
                    {
                      for (octave_idx_type i = 0; i < b_nr; i++)
                        Bx[i] = b.elem (i, j);

                      F77_XFCN (zpbtrs, ZPBTRS,
                                (F77_CONST_CHAR_ARG2 (&job, 1),
                                 nr, n_lower, 1, tmp_data,
                                 ldm, Bx, b_nr, err
                                 F77_CHAR_ARG_LEN (1)));

                      if (err != 0)
                        {
                          (*current_liboctave_error_handler)
                            ("SparseComplexMatrix::solve solve failed");
                          err = -1;
                          break;
                        }

                      for (octave_idx_type i = 0; i < b_nr; i++)
                        {
                          Complex tmp = Bx[i];
                          if (tmp != 0.0)
                            {
                              if (ii == x_nz)
                                {
                                  // Resize the sparse matrix
                                  octave_idx_type sz = x_nz *
                                    (b_nc - j) / b_nc;
                                  sz = (sz > 10 ? sz : 10) + x_nz;
                                  retval.change_capacity (sz);
                                  x_nz = sz;
                                }
                              retval.xdata (ii) = tmp;
                              retval.xridx (ii++) = i;
                            }
                        }
                      retval.xcidx (j+1) = ii;
                    }

                  retval.maybe_compress ();
                }
            }
        }

      if (typ == MatrixType::Banded)
        {
          // Create the storage for the banded form of the sparse matrix
          octave_idx_type n_upper = mattype.nupper ();
          octave_idx_type n_lower = mattype.nlower ();
          octave_idx_type ldm = n_upper + 2 * n_lower + 1;

          ComplexMatrix m_band (ldm, nc);
          Complex *tmp_data = m_band.fortran_vec ();

          if (! mattype.is_dense ())
            {
              octave_idx_type ii = 0;

              for (octave_idx_type j = 0; j < ldm; j++)
                for (octave_idx_type i = 0; i < nc; i++)
                  tmp_data[ii++] = 0.;
            }

          for (octave_idx_type j = 0; j < nc; j++)
            for (octave_idx_type i = cidx (j); i < cidx (j+1); i++)
              m_band(ridx (i) - j + n_lower + n_upper, j) = data (i);

          // Calculate the norm of the matrix, for later use.
          double anorm;
          if (calc_cond)
            {
              for (octave_idx_type j = 0; j < nr; j++)
                {
                  double atmp = 0.;
                  for (octave_idx_type i = cidx (j); i < cidx (j+1); i++)
                    atmp += std::abs (data (i));
                  if (atmp > anorm)
                    anorm = atmp;
                }
            }

          Array<octave_idx_type> ipvt (dim_vector (nr, 1));
          octave_idx_type *pipvt = ipvt.fortran_vec ();

          F77_XFCN (zgbtrf, ZGBTRF, (nr, nr, n_lower, n_upper, tmp_data,
                                     ldm, pipvt, err));

          if (err != 0)
            {
              rcond = 0.0;
              err = -2;

              if (sing_handler)
                {
                sing_handler (rcond);
                mattype.mark_as_rectangular ();
                }
              else
                (*current_liboctave_error_handler)
                  ("matrix singular to machine precision");

            }
          else
            {
              if (calc_cond)
                {
                  char job = '1';
                  Array<Complex> z (dim_vector (2 * nr, 1));
                  Complex *pz = z.fortran_vec ();
                  Array<double> iz (dim_vector (nr, 1));
                  double *piz = iz.fortran_vec ();

                  F77_XFCN (zgbcon, ZGBCON,
                    (F77_CONST_CHAR_ARG2 (&job, 1),
                     nc, n_lower, n_upper, tmp_data, ldm, pipvt,
                     anorm, rcond, pz, piz, err
                     F77_CHAR_ARG_LEN (1)));

                   if (err != 0)
                    err = -2;

                  volatile double rcond_plus_one = rcond + 1.0;

                  if (rcond_plus_one == 1.0 || xisnan (rcond))
                    {
                      err = -2;

                      if (sing_handler)
                        {
                          sing_handler (rcond);
                          mattype.mark_as_rectangular ();
                        }
                      else
                        (*current_liboctave_error_handler)
                          ("matrix singular to machine precision, rcond = %g",
                           rcond);
                    }
                }
              else
                rcond = 1.;

              if (err == 0)
                {
                  char job = 'N';
                  volatile octave_idx_type x_nz = b.nnz ();
                  octave_idx_type b_nc = b.cols ();
                  retval = SparseComplexMatrix (nr, b_nc, x_nz);
                  retval.xcidx (0) = 0;
                  volatile octave_idx_type ii = 0;

                  OCTAVE_LOCAL_BUFFER (Complex, work, nr);

                  for (volatile octave_idx_type j = 0; j < b_nc; j++)
                    {
                      for (octave_idx_type i = 0; i < nr; i++)
                        work[i] = 0.;
                      for (octave_idx_type i = b.cidx (j);
                           i < b.cidx (j+1); i++)
                        work[b.ridx (i)] = b.data (i);

                      F77_XFCN (zgbtrs, ZGBTRS,
                                (F77_CONST_CHAR_ARG2 (&job, 1),
                                 nr, n_lower, n_upper, 1, tmp_data,
                                 ldm, pipvt, work, b.rows (), err
                                 F77_CHAR_ARG_LEN (1)));

                      // Count non-zeros in work vector and adjust
                      // space in retval if needed
                      octave_idx_type new_nnz = 0;
                      for (octave_idx_type i = 0; i < nr; i++)
                        if (work[i] != 0.)
                          new_nnz++;

                      if (ii + new_nnz > x_nz)
                        {
                          // Resize the sparse matrix
                          octave_idx_type sz = new_nnz * (b_nc - j) + x_nz;
                          retval.change_capacity (sz);
                          x_nz = sz;
                        }

                      for (octave_idx_type i = 0; i < nr; i++)
                        if (work[i] != 0.)
                          {
                            retval.xridx (ii) = i;
                            retval.xdata (ii++) = work[i];
                          }
                      retval.xcidx (j+1) = ii;
                    }

                  retval.maybe_compress ();
                }
            }
        }
      else if (typ != MatrixType::Banded_Hermitian)
        (*current_liboctave_error_handler) ("incorrect matrix type");
    }

  return retval;
}

ComplexMatrix
SparseComplexMatrix::bsolve (MatrixType &mattype, const ComplexMatrix& b,
                             octave_idx_type& err, double& rcond,
                             solve_singularity_handler sing_handler,
                             bool calc_cond) const
{
  ComplexMatrix retval;

  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();
  err = 0;

  if (nr != nc || nr != b.rows ())
    (*current_liboctave_error_handler)
      ("matrix dimension mismatch solution of linear equations");
  else if (nr == 0 || b.cols () == 0)
    retval = ComplexMatrix (nc, b.cols (), Complex (0.0, 0.0));
  else
    {
      // Print spparms("spumoni") info if requested
      volatile int typ = mattype.type ();
      mattype.info ();

      if (typ == MatrixType::Banded_Hermitian)
        {
          octave_idx_type n_lower = mattype.nlower ();
          octave_idx_type ldm = n_lower + 1;

          ComplexMatrix m_band (ldm, nc);
          Complex *tmp_data = m_band.fortran_vec ();

          if (! mattype.is_dense ())
            {
              octave_idx_type ii = 0;

              for (octave_idx_type j = 0; j < ldm; j++)
                for (octave_idx_type i = 0; i < nc; i++)
                  tmp_data[ii++] = 0.;
            }

          for (octave_idx_type j = 0; j < nc; j++)
            for (octave_idx_type i = cidx (j); i < cidx (j+1); i++)
              {
                octave_idx_type ri = ridx (i);
                if (ri >= j)
                  m_band(ri - j, j) = data (i);
              }

          // Calculate the norm of the matrix, for later use.
          double anorm;
          if (calc_cond)
            anorm = m_band.abs ().sum ().row (0).max ();

          char job = 'L';
          F77_XFCN (zpbtrf, ZPBTRF, (F77_CONST_CHAR_ARG2 (&job, 1),
                                     nr, n_lower, tmp_data, ldm, err
                                     F77_CHAR_ARG_LEN (1)));

          if (err != 0)
            {
              // Matrix is not positive definite!! Fall through to
              // unsymmetric banded solver.
              rcond = 0.0;
              mattype.mark_as_unsymmetric ();
              typ = MatrixType::Banded;
              err = 0;
            }
          else
            {
              if (calc_cond)
                {
                  Array<Complex> z (dim_vector (2 * nr, 1));
                  Complex *pz = z.fortran_vec ();
                  Array<double> iz (dim_vector (nr, 1));
                  double *piz = iz.fortran_vec ();

                  F77_XFCN (zpbcon, ZPBCON,
                    (F77_CONST_CHAR_ARG2 (&job, 1),
                     nr, n_lower, tmp_data, ldm,
                     anorm, rcond, pz, piz, err
                     F77_CHAR_ARG_LEN (1)));

                  if (err != 0)
                    err = -2;

                  volatile double rcond_plus_one = rcond + 1.0;

                  if (rcond_plus_one == 1.0 || xisnan (rcond))
                    {
                      err = -2;

                      if (sing_handler)
                        {
                          sing_handler (rcond);
                          mattype.mark_as_rectangular ();
                        }
                      else
                        (*current_liboctave_error_handler)
                          ("matrix singular to machine precision, rcond = %g",
                           rcond);
                    }
                }
              else
                rcond = 1.0;

              if (err == 0)
                {
                  octave_idx_type b_nr = b.rows ();
                  octave_idx_type b_nc = b.cols ();
                  retval = ComplexMatrix (b);
                  Complex *result = retval.fortran_vec ();

                  F77_XFCN (zpbtrs, ZPBTRS,
                            (F77_CONST_CHAR_ARG2 (&job, 1),
                             nr, n_lower, b_nc, tmp_data,
                             ldm, result, b_nr, err
                             F77_CHAR_ARG_LEN (1)));

                  if (err != 0)
                    {
                      (*current_liboctave_error_handler)
                        ("SparseComplexMatrix::solve solve failed");
                      err = -1;
                    }
                }
            }
        }

      if (typ == MatrixType::Banded)
        {
          // Create the storage for the banded form of the sparse matrix
          octave_idx_type n_upper = mattype.nupper ();
          octave_idx_type n_lower = mattype.nlower ();
          octave_idx_type ldm = n_upper + 2 * n_lower + 1;

          ComplexMatrix m_band (ldm, nc);
          Complex *tmp_data = m_band.fortran_vec ();

          if (! mattype.is_dense ())
            {
              octave_idx_type ii = 0;

              for (octave_idx_type j = 0; j < ldm; j++)
                for (octave_idx_type i = 0; i < nc; i++)
                  tmp_data[ii++] = 0.;
            }

          for (octave_idx_type j = 0; j < nc; j++)
            for (octave_idx_type i = cidx (j); i < cidx (j+1); i++)
              m_band(ridx (i) - j + n_lower + n_upper, j) = data (i);

          // Calculate the norm of the matrix, for later use.
          double anorm;
          if (calc_cond)
            {
              for (octave_idx_type j = 0; j < nr; j++)
                {
                  double atmp = 0.;
                  for (octave_idx_type i = cidx (j); i < cidx (j+1); i++)
                    atmp += std::abs (data (i));
                  if (atmp > anorm)
                    anorm = atmp;
                }
            }

          Array<octave_idx_type> ipvt (dim_vector (nr, 1));
          octave_idx_type *pipvt = ipvt.fortran_vec ();

          F77_XFCN (zgbtrf, ZGBTRF, (nr, nr, n_lower, n_upper, tmp_data,
                                     ldm, pipvt, err));

          if (err != 0)
            {
              err = -2;
              rcond = 0.0;

              if (sing_handler)
                {
                  sing_handler (rcond);
                  mattype.mark_as_rectangular ();
                }
              else
                (*current_liboctave_error_handler)
                  ("matrix singular to machine precision");
            }
          else
            {
              if (calc_cond)
                {
                  char job = '1';
                  Array<Complex> z (dim_vector (2 * nr, 1));
                  Complex *pz = z.fortran_vec ();
                  Array<double> iz (dim_vector (nr, 1));
                  double *piz = iz.fortran_vec ();

                  F77_XFCN (zgbcon, ZGBCON,
                    (F77_CONST_CHAR_ARG2 (&job, 1),
                     nc, n_lower, n_upper, tmp_data, ldm, pipvt,
                     anorm, rcond, pz, piz, err
                     F77_CHAR_ARG_LEN (1)));

                   if (err != 0)
                    err = -2;

                  volatile double rcond_plus_one = rcond + 1.0;

                  if (rcond_plus_one == 1.0 || xisnan (rcond))
                    {
                      err = -2;

                      if (sing_handler)
                        {
                          sing_handler (rcond);
                          mattype.mark_as_rectangular ();
                        }
                      else
                        (*current_liboctave_error_handler)
                          ("matrix singular to machine precision, rcond = %g",
                           rcond);
                    }
                }
              else
                rcond = 1.;

              if (err == 0)
                {
                  char job = 'N';
                  octave_idx_type b_nc = b.cols ();
                  retval = ComplexMatrix (b);
                  Complex *result = retval.fortran_vec ();

                  F77_XFCN (zgbtrs, ZGBTRS,
                            (F77_CONST_CHAR_ARG2 (&job, 1),
                             nr, n_lower, n_upper, b_nc, tmp_data,
                             ldm, pipvt, result, b.rows (), err
                             F77_CHAR_ARG_LEN (1)));
                }
            }
        }
      else if (typ != MatrixType::Banded_Hermitian)
        (*current_liboctave_error_handler) ("incorrect matrix type");
    }

  return retval;
}

SparseComplexMatrix
SparseComplexMatrix::bsolve (MatrixType &mattype, const SparseComplexMatrix& b,
                             octave_idx_type& err, double& rcond,
                             solve_singularity_handler sing_handler,
                             bool calc_cond) const
{
  SparseComplexMatrix retval;

  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();
  err = 0;

  if (nr != nc || nr != b.rows ())
    (*current_liboctave_error_handler)
      ("matrix dimension mismatch solution of linear equations");
  else if (nr == 0 || b.cols () == 0)
    retval = SparseComplexMatrix (nc, b.cols ());
  else
    {
      // Print spparms("spumoni") info if requested
      volatile int typ = mattype.type ();
      mattype.info ();

      if (typ == MatrixType::Banded_Hermitian)
        {
          octave_idx_type n_lower = mattype.nlower ();
          octave_idx_type ldm = n_lower + 1;

          ComplexMatrix m_band (ldm, nc);
          Complex *tmp_data = m_band.fortran_vec ();

          if (! mattype.is_dense ())
            {
              octave_idx_type ii = 0;

              for (octave_idx_type j = 0; j < ldm; j++)
                for (octave_idx_type i = 0; i < nc; i++)
                  tmp_data[ii++] = 0.;
            }

          for (octave_idx_type j = 0; j < nc; j++)
            for (octave_idx_type i = cidx (j); i < cidx (j+1); i++)
              {
                octave_idx_type ri = ridx (i);
                if (ri >= j)
                  m_band(ri - j, j) = data (i);
              }

          // Calculate the norm of the matrix, for later use.
          double anorm;
          if (calc_cond)
            anorm = m_band.abs ().sum ().row (0).max ();

          char job = 'L';
          F77_XFCN (zpbtrf, ZPBTRF, (F77_CONST_CHAR_ARG2 (&job, 1),
                                     nr, n_lower, tmp_data, ldm, err
                                     F77_CHAR_ARG_LEN (1)));

          if (err != 0)
            {
              // Matrix is not positive definite!! Fall through to
              // unsymmetric banded solver.
              mattype.mark_as_unsymmetric ();
              typ = MatrixType::Banded;

              rcond = 0.0;
              err = 0;
            }
          else
            {
              if (calc_cond)
                {
                  Array<Complex> z (dim_vector (2 * nr, 1));
                  Complex *pz = z.fortran_vec ();
                  Array<double> iz (dim_vector (nr, 1));
                  double *piz = iz.fortran_vec ();

                  F77_XFCN (zpbcon, ZPBCON,
                    (F77_CONST_CHAR_ARG2 (&job, 1),
                     nr, n_lower, tmp_data, ldm,
                     anorm, rcond, pz, piz, err
                     F77_CHAR_ARG_LEN (1)));

                  if (err != 0)
                    err = -2;

                  volatile double rcond_plus_one = rcond + 1.0;

                  if (rcond_plus_one == 1.0 || xisnan (rcond))
                    {
                      err = -2;

                      if (sing_handler)
                        {
                          sing_handler (rcond);
                          mattype.mark_as_rectangular ();
                        }
                      else
                        (*current_liboctave_error_handler)
                          ("matrix singular to machine precision, rcond = %g",
                           rcond);
                    }
                }
              else
                rcond = 1.0;

              if (err == 0)
                {
                  octave_idx_type b_nr = b.rows ();
                  octave_idx_type b_nc = b.cols ();
                  OCTAVE_LOCAL_BUFFER (Complex, Bx, b_nr);

                  // Take a first guess that the number of non-zero terms
                  // will be as many as in b
                  volatile octave_idx_type x_nz = b.nnz ();
                  volatile octave_idx_type ii = 0;
                  retval = SparseComplexMatrix (b_nr, b_nc, x_nz);

                  retval.xcidx (0) = 0;
                  for (volatile octave_idx_type j = 0; j < b_nc; j++)
                    {

                      for (octave_idx_type i = 0; i < b_nr; i++)
                        Bx[i] = b (i,j);

                      F77_XFCN (zpbtrs, ZPBTRS,
                                (F77_CONST_CHAR_ARG2 (&job, 1),
                                 nr, n_lower, 1, tmp_data,
                                 ldm, Bx, b_nr, err
                                 F77_CHAR_ARG_LEN (1)));

                      if (err != 0)
                        {
                          (*current_liboctave_error_handler)
                            ("SparseMatrix::solve solve failed");
                          err = -1;
                          break;
                        }

                      // Count non-zeros in work vector and adjust
                      // space in retval if needed
                      octave_idx_type new_nnz = 0;
                      for (octave_idx_type i = 0; i < nr; i++)
                        if (Bx[i] != 0.)
                          new_nnz++;

                      if (ii + new_nnz > x_nz)
                        {
                          // Resize the sparse matrix
                          octave_idx_type sz = new_nnz * (b_nc - j) + x_nz;
                          retval.change_capacity (sz);
                          x_nz = sz;
                        }

                      for (octave_idx_type i = 0; i < nr; i++)
                        if (Bx[i] != 0.)
                          {
                            retval.xridx (ii) = i;
                            retval.xdata (ii++) = Bx[i];
                          }

                      retval.xcidx (j+1) = ii;
                    }

                  retval.maybe_compress ();
                }
            }
        }

      if (typ == MatrixType::Banded)
        {
          // Create the storage for the banded form of the sparse matrix
          octave_idx_type n_upper = mattype.nupper ();
          octave_idx_type n_lower = mattype.nlower ();
          octave_idx_type ldm = n_upper + 2 * n_lower + 1;

          ComplexMatrix m_band (ldm, nc);
          Complex *tmp_data = m_band.fortran_vec ();

          if (! mattype.is_dense ())
            {
              octave_idx_type ii = 0;

              for (octave_idx_type j = 0; j < ldm; j++)
                for (octave_idx_type i = 0; i < nc; i++)
                  tmp_data[ii++] = 0.;
            }

          for (octave_idx_type j = 0; j < nc; j++)
            for (octave_idx_type i = cidx (j); i < cidx (j+1); i++)
              m_band(ridx (i) - j + n_lower + n_upper, j) = data (i);

          // Calculate the norm of the matrix, for later use.
          double anorm;
          if (calc_cond)
            {
              for (octave_idx_type j = 0; j < nr; j++)
                {
                  double atmp = 0.;
                  for (octave_idx_type i = cidx (j); i < cidx (j+1); i++)
                    atmp += std::abs (data (i));
                  if (atmp > anorm)
                    anorm = atmp;
                }
            }

          Array<octave_idx_type> ipvt (dim_vector (nr, 1));
          octave_idx_type *pipvt = ipvt.fortran_vec ();

          F77_XFCN (zgbtrf, ZGBTRF, (nr, nr, n_lower, n_upper, tmp_data,
                                     ldm, pipvt, err));

          if (err != 0)
            {
              err = -2;
              rcond = 0.0;

              if (sing_handler)
                {
                  sing_handler (rcond);
                  mattype.mark_as_rectangular ();
                }
              else
                (*current_liboctave_error_handler)
                  ("matrix singular to machine precision");

            }
          else
            {
              if (calc_cond)
                {
                  char job = '1';
                  Array<Complex> z (dim_vector (2 * nr, 1));
                  Complex *pz = z.fortran_vec ();
                  Array<double> iz (dim_vector (nr, 1));
                  double *piz = iz.fortran_vec ();

                  F77_XFCN (zgbcon, ZGBCON,
                    (F77_CONST_CHAR_ARG2 (&job, 1),
                     nc, n_lower, n_upper, tmp_data, ldm, pipvt,
                     anorm, rcond, pz, piz, err
                     F77_CHAR_ARG_LEN (1)));

                   if (err != 0)
                    err = -2;

                  volatile double rcond_plus_one = rcond + 1.0;

                  if (rcond_plus_one == 1.0 || xisnan (rcond))
                    {
                      err = -2;

                      if (sing_handler)
                        {
                          sing_handler (rcond);
                          mattype.mark_as_rectangular ();
                        }
                      else
                        (*current_liboctave_error_handler)
                          ("matrix singular to machine precision, rcond = %g",
                           rcond);
                    }
                }
              else
                rcond = 1.;

              if (err == 0)
                {
                  char job = 'N';
                  volatile octave_idx_type x_nz = b.nnz ();
                  octave_idx_type b_nc = b.cols ();
                  retval = SparseComplexMatrix (nr, b_nc, x_nz);
                  retval.xcidx (0) = 0;
                  volatile octave_idx_type ii = 0;

                  OCTAVE_LOCAL_BUFFER (Complex, Bx, nr);

                  for (volatile octave_idx_type j = 0; j < b_nc; j++)
                    {
                      for (octave_idx_type i = 0; i < nr; i++)
                        Bx[i] = 0.;

                      for (octave_idx_type i = b.cidx (j);
                           i < b.cidx (j+1); i++)
                        Bx[b.ridx (i)] = b.data (i);

                      F77_XFCN (zgbtrs, ZGBTRS,
                                (F77_CONST_CHAR_ARG2 (&job, 1),
                                 nr, n_lower, n_upper, 1, tmp_data,
                                 ldm, pipvt, Bx, b.rows (), err
                                 F77_CHAR_ARG_LEN (1)));

                      // Count non-zeros in work vector and adjust
                      // space in retval if needed
                      octave_idx_type new_nnz = 0;
                      for (octave_idx_type i = 0; i < nr; i++)
                        if (Bx[i] != 0.)
                          new_nnz++;

                      if (ii + new_nnz > x_nz)
                        {
                          // Resize the sparse matrix
                          octave_idx_type sz = new_nnz * (b_nc - j) + x_nz;
                          retval.change_capacity (sz);
                          x_nz = sz;
                        }

                      for (octave_idx_type i = 0; i < nr; i++)
                        if (Bx[i] != 0.)
                          {
                            retval.xridx (ii) = i;
                            retval.xdata (ii++) = Bx[i];
                          }
                      retval.xcidx (j+1) = ii;
                    }

                  retval.maybe_compress ();
                }
            }
        }
      else if (typ != MatrixType::Banded_Hermitian)
        (*current_liboctave_error_handler) ("incorrect matrix type");
    }

  return retval;
}

void *
SparseComplexMatrix::factorize (octave_idx_type& err, double &rcond,
                                Matrix &Control, Matrix &Info,
                                solve_singularity_handler sing_handler,
                                bool calc_cond) const
{
  // The return values
  void *Numeric = 0;
  err = 0;

#ifdef HAVE_UMFPACK
  // Setup the control parameters
  Control = Matrix (UMFPACK_CONTROL, 1);
  double *control = Control.fortran_vec ();
  UMFPACK_ZNAME (defaults) (control);

  double tmp = octave_sparse_params::get_key ("spumoni");
  if (!xisnan (tmp))
    Control (UMFPACK_PRL) = tmp;
  tmp = octave_sparse_params::get_key ("piv_tol");
  if (!xisnan (tmp))
    {
      Control (UMFPACK_SYM_PIVOT_TOLERANCE) = tmp;
      Control (UMFPACK_PIVOT_TOLERANCE) = tmp;
    }

  // Set whether we are allowed to modify Q or not
  tmp = octave_sparse_params::get_key ("autoamd");
  if (!xisnan (tmp))
    Control (UMFPACK_FIXQ) = tmp;

  UMFPACK_ZNAME (report_control) (control);

  const octave_idx_type *Ap = cidx ();
  const octave_idx_type *Ai = ridx ();
  const Complex *Ax = data ();
  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();

  UMFPACK_ZNAME (report_matrix) (nr, nc, Ap, Ai,
                                 reinterpret_cast<const double *> (Ax),
                                 0, 1, control);

  void *Symbolic;
  Info = Matrix (1, UMFPACK_INFO);
  double *info = Info.fortran_vec ();
  int status = UMFPACK_ZNAME (qsymbolic) (nr, nc, Ap, Ai,
                                     reinterpret_cast<const double *> (Ax),
                                     0, 0, &Symbolic, control, info);

  if (status < 0)
    {
      (*current_liboctave_error_handler)
        ("SparseComplexMatrix::solve symbolic factorization failed");
      err = -1;

      UMFPACK_ZNAME (report_status) (control, status);
      UMFPACK_ZNAME (report_info) (control, info);

      UMFPACK_ZNAME (free_symbolic) (&Symbolic) ;
    }
  else
    {
      UMFPACK_ZNAME (report_symbolic) (Symbolic, control);

      status = UMFPACK_ZNAME (numeric) (Ap, Ai,
                                   reinterpret_cast<const double *> (Ax), 0,
                                   Symbolic, &Numeric, control, info) ;
      UMFPACK_ZNAME (free_symbolic) (&Symbolic) ;

      if (calc_cond)
        rcond = Info (UMFPACK_RCOND);
      else
        rcond = 1.;
      volatile double rcond_plus_one = rcond + 1.0;

      if (status == UMFPACK_WARNING_singular_matrix ||
          rcond_plus_one == 1.0 || xisnan (rcond))
        {
          UMFPACK_ZNAME (report_numeric) (Numeric, control);

          err = -2;

          if (sing_handler)
            sing_handler (rcond);
          else
            (*current_liboctave_error_handler)
              ("SparseComplexMatrix::solve matrix singular to machine precision, rcond = %g",
               rcond);

        }
      else if (status < 0)
          {
            (*current_liboctave_error_handler)
              ("SparseComplexMatrix::solve numeric factorization failed");

            UMFPACK_ZNAME (report_status) (control, status);
            UMFPACK_ZNAME (report_info) (control, info);

            err = -1;
          }
        else
          {
            UMFPACK_ZNAME (report_numeric) (Numeric, control);
          }
    }

  if (err != 0)
    UMFPACK_ZNAME (free_numeric) (&Numeric);
#else
  (*current_liboctave_error_handler) ("UMFPACK not installed");
#endif

  return Numeric;
}

ComplexMatrix
SparseComplexMatrix::fsolve (MatrixType &mattype, const Matrix& b,
                             octave_idx_type& err, double& rcond,
                             solve_singularity_handler sing_handler,
                             bool calc_cond) const
{
  ComplexMatrix retval;

  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();
  err = 0;

  if (nr != nc || nr != b.rows ())
    (*current_liboctave_error_handler)
      ("matrix dimension mismatch solution of linear equations");
  else if (nr == 0 || b.cols () == 0)
    retval = ComplexMatrix (nc, b.cols (), Complex (0.0, 0.0));
  else
    {
      // Print spparms("spumoni") info if requested
      volatile int typ = mattype.type ();
      mattype.info ();

      if (typ == MatrixType::Hermitian)
        {
#ifdef HAVE_CHOLMOD
          cholmod_common Common;
          cholmod_common *cm = &Common;

          // Setup initial parameters
          CHOLMOD_NAME(start) (cm);
          cm->prefer_zomplex = false;

          double spu = octave_sparse_params::get_key ("spumoni");
          if (spu == 0.)
            {
              cm->print = -1;
              cm->print_function = 0;
            }
          else
            {
              cm->print = static_cast<int> (spu) + 2;
              cm->print_function =&SparseCholPrint;
            }

          cm->error_handler = &SparseCholError;
          cm->complex_divide = CHOLMOD_NAME(divcomplex);
          cm->hypotenuse = CHOLMOD_NAME(hypot);

          cm->final_ll = true;

          cholmod_sparse Astore;
          cholmod_sparse *A = &Astore;
          double dummy;
          A->nrow = nr;
          A->ncol = nc;

          A->p = cidx ();
          A->i = ridx ();
          A->nzmax = nnz ();
          A->packed = true;
          A->sorted = true;
          A->nz = 0;
#ifdef USE_64_BIT_IDX_T
          A->itype = CHOLMOD_LONG;
#else
          A->itype = CHOLMOD_INT;
#endif
          A->dtype = CHOLMOD_DOUBLE;
          A->stype = 1;
          A->xtype = CHOLMOD_COMPLEX;

          if (nr < 1)
            A->x = &dummy;
          else
            A->x = data ();

          cholmod_dense Bstore;
          cholmod_dense *B = &Bstore;
          B->nrow = b.rows ();
          B->ncol = b.cols ();
          B->d = B->nrow;
          B->nzmax = B->nrow * B->ncol;
          B->dtype = CHOLMOD_DOUBLE;
          B->xtype = CHOLMOD_REAL;
          if (nc < 1 || b.cols () < 1)
            B->x = &dummy;
          else
            // We won't alter it, honest :-)
            B->x = const_cast<double *>(b.fortran_vec ());

          cholmod_factor *L;
          BEGIN_INTERRUPT_IMMEDIATELY_IN_FOREIGN_CODE;
          L = CHOLMOD_NAME(analyze) (A, cm);
          CHOLMOD_NAME(factorize) (A, L, cm);
          if (calc_cond)
            rcond = CHOLMOD_NAME(rcond)(L, cm);
          else
            rcond = 1.;
          END_INTERRUPT_IMMEDIATELY_IN_FOREIGN_CODE;

          if (rcond == 0.0)
            {
              // Either its indefinite or singular. Try UMFPACK
              mattype.mark_as_unsymmetric ();
              typ = MatrixType::Full;
            }
          else
            {
              volatile double rcond_plus_one = rcond + 1.0;

              if (rcond_plus_one == 1.0 || xisnan (rcond))
                {
                  err = -2;

                  if (sing_handler)
                    {
                      sing_handler (rcond);
                      mattype.mark_as_rectangular ();
                    }
                  else
                    (*current_liboctave_error_handler)
                      ("SparseMatrix::solve matrix singular to machine precision, rcond = %g",
                       rcond);

                  return retval;
                }

              cholmod_dense *X;
              BEGIN_INTERRUPT_IMMEDIATELY_IN_FOREIGN_CODE;
              X = CHOLMOD_NAME(solve) (CHOLMOD_A, L, B, cm);
              END_INTERRUPT_IMMEDIATELY_IN_FOREIGN_CODE;

              retval.resize (b.rows (), b.cols ());
              for (octave_idx_type j = 0; j < b.cols (); j++)
                {
                  octave_idx_type jr = j * b.rows ();
                  for (octave_idx_type i = 0; i < b.rows (); i++)
                    retval.xelem (i,j) = static_cast<Complex *>(X->x)[jr + i];
                }

              BEGIN_INTERRUPT_IMMEDIATELY_IN_FOREIGN_CODE;
              CHOLMOD_NAME(free_dense) (&X, cm);
              CHOLMOD_NAME(free_factor) (&L, cm);
              CHOLMOD_NAME(finish) (cm);
              static char tmp[] = " ";
              CHOLMOD_NAME(print_common) (tmp, cm);
              END_INTERRUPT_IMMEDIATELY_IN_FOREIGN_CODE;
            }
#else
          (*current_liboctave_warning_handler)
            ("CHOLMOD not installed");

          mattype.mark_as_unsymmetric ();
          typ = MatrixType::Full;
#endif
        }

      if (typ == MatrixType::Full)
        {
#ifdef HAVE_UMFPACK
          Matrix Control, Info;
          void *Numeric = factorize (err, rcond, Control, Info,
                                     sing_handler, calc_cond);

          if (err == 0)
            {
              octave_idx_type b_nr = b.rows ();
              octave_idx_type b_nc = b.cols ();
              int status = 0;
              double *control = Control.fortran_vec ();
              double *info = Info.fortran_vec ();
              const octave_idx_type *Ap = cidx ();
              const octave_idx_type *Ai = ridx ();
              const Complex *Ax = data ();
#ifdef UMFPACK_SEPARATE_SPLIT
              const double *Bx = b.fortran_vec ();
              OCTAVE_LOCAL_BUFFER (double, Bz, b_nr);
              for (octave_idx_type i = 0; i < b_nr; i++)
                Bz[i] = 0.;
#else
              OCTAVE_LOCAL_BUFFER (Complex, Bz, b_nr);
#endif
              retval.resize (b_nr, b_nc);
              Complex *Xx = retval.fortran_vec ();

              for (octave_idx_type j = 0, iidx = 0; j < b_nc; j++, iidx += b_nr)
                {
#ifdef UMFPACK_SEPARATE_SPLIT
                  status = UMFPACK_ZNAME (solve) (UMFPACK_A, Ap,
                                             Ai,
                                             reinterpret_cast<const double *> (Ax),
                                             0,
                                             reinterpret_cast<double *> (&Xx[iidx]),
                                             0,
                                             &Bx[iidx], Bz, Numeric,
                                             control, info);
#else
                  for (octave_idx_type i = 0; i < b_nr; i++)
                    Bz[i] = b.elem (i, j);

                  status = UMFPACK_ZNAME (solve) (UMFPACK_A, Ap,
                                             Ai,
                                             reinterpret_cast<const double *> (Ax),
                                             0,
                                             reinterpret_cast<double *> (&Xx[iidx]),
                                             0,
                                             reinterpret_cast<const double *> (Bz),
                                             0, Numeric,
                                             control, info);
#endif

                  if (status < 0)
                    {
                      (*current_liboctave_error_handler)
                        ("SparseComplexMatrix::solve solve failed");

                      UMFPACK_ZNAME (report_status) (control, status);

                      err = -1;

                      break;
                    }
                }

              UMFPACK_ZNAME (report_info) (control, info);

              UMFPACK_ZNAME (free_numeric) (&Numeric);
            }
          else
            mattype.mark_as_rectangular ();

#else
          (*current_liboctave_error_handler) ("UMFPACK not installed");
#endif
        }
      else if (typ != MatrixType::Hermitian)
        (*current_liboctave_error_handler) ("incorrect matrix type");
    }

  return retval;
}

SparseComplexMatrix
SparseComplexMatrix::fsolve (MatrixType &mattype, const SparseMatrix& b,
                             octave_idx_type& err, double& rcond,
                             solve_singularity_handler sing_handler,
                             bool calc_cond) const
{
  SparseComplexMatrix retval;

  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();
  err = 0;

  if (nr != nc || nr != b.rows ())
    (*current_liboctave_error_handler)
      ("matrix dimension mismatch solution of linear equations");
  else if (nr == 0 || b.cols () == 0)
    retval = SparseComplexMatrix (nc, b.cols ());
  else
    {
      // Print spparms("spumoni") info if requested
      volatile int typ = mattype.type ();
      mattype.info ();

      if (typ == MatrixType::Hermitian)
        {
#ifdef HAVE_CHOLMOD
          cholmod_common Common;
          cholmod_common *cm = &Common;

          // Setup initial parameters
          CHOLMOD_NAME(start) (cm);
          cm->prefer_zomplex = false;

          double spu = octave_sparse_params::get_key ("spumoni");
          if (spu == 0.)
            {
              cm->print = -1;
              cm->print_function = 0;
            }
          else
            {
              cm->print = static_cast<int> (spu) + 2;
              cm->print_function =&SparseCholPrint;
            }

          cm->error_handler = &SparseCholError;
          cm->complex_divide = CHOLMOD_NAME(divcomplex);
          cm->hypotenuse = CHOLMOD_NAME(hypot);

          cm->final_ll = true;

          cholmod_sparse Astore;
          cholmod_sparse *A = &Astore;
          double dummy;
          A->nrow = nr;
          A->ncol = nc;

          A->p = cidx ();
          A->i = ridx ();
          A->nzmax = nnz ();
          A->packed = true;
          A->sorted = true;
          A->nz = 0;
#ifdef USE_64_BIT_IDX_T
          A->itype = CHOLMOD_LONG;
#else
          A->itype = CHOLMOD_INT;
#endif
          A->dtype = CHOLMOD_DOUBLE;
          A->stype = 1;
          A->xtype = CHOLMOD_COMPLEX;

          if (nr < 1)
            A->x = &dummy;
          else
            A->x = data ();

          cholmod_sparse Bstore;
          cholmod_sparse *B = &Bstore;
          B->nrow = b.rows ();
          B->ncol = b.cols ();
          B->p = b.cidx ();
          B->i = b.ridx ();
          B->nzmax = b.nnz ();
          B->packed = true;
          B->sorted = true;
          B->nz = 0;
#ifdef USE_64_BIT_IDX_T
          B->itype = CHOLMOD_LONG;
#else
          B->itype = CHOLMOD_INT;
#endif
          B->dtype = CHOLMOD_DOUBLE;
          B->stype = 0;
          B->xtype = CHOLMOD_REAL;

          if (b.rows () < 1 || b.cols () < 1)
            B->x = &dummy;
          else
            B->x = b.data ();

          cholmod_factor *L;
          BEGIN_INTERRUPT_IMMEDIATELY_IN_FOREIGN_CODE;
          L = CHOLMOD_NAME(analyze) (A, cm);
          CHOLMOD_NAME(factorize) (A, L, cm);
          if (calc_cond)
            rcond = CHOLMOD_NAME(rcond)(L, cm);
          else
            rcond = 1.;
          END_INTERRUPT_IMMEDIATELY_IN_FOREIGN_CODE;

          if (rcond == 0.0)
            {
              // Either its indefinite or singular. Try UMFPACK
              mattype.mark_as_unsymmetric ();
              typ = MatrixType::Full;
            }
          else
            {
              volatile double rcond_plus_one = rcond + 1.0;

              if (rcond_plus_one == 1.0 || xisnan (rcond))
                {
                  err = -2;

                  if (sing_handler)
                    {
                      sing_handler (rcond);
                      mattype.mark_as_rectangular ();
                    }
                  else
                    (*current_liboctave_error_handler)
                      ("SparseMatrix::solve matrix singular to machine precision, rcond = %g",
                       rcond);

                  return retval;
                }

              cholmod_sparse *X;
              BEGIN_INTERRUPT_IMMEDIATELY_IN_FOREIGN_CODE;
              X = CHOLMOD_NAME(spsolve) (CHOLMOD_A, L, B, cm);
              END_INTERRUPT_IMMEDIATELY_IN_FOREIGN_CODE;

              retval = SparseComplexMatrix
                (static_cast<octave_idx_type>(X->nrow),
                 static_cast<octave_idx_type>(X->ncol),
                 static_cast<octave_idx_type>(X->nzmax));
              for (octave_idx_type j = 0;
                   j <= static_cast<octave_idx_type>(X->ncol); j++)
                retval.xcidx (j) = static_cast<octave_idx_type *>(X->p)[j];
              for (octave_idx_type j = 0;
                   j < static_cast<octave_idx_type>(X->nzmax); j++)
                {
                  retval.xridx (j) = static_cast<octave_idx_type *>(X->i)[j];
                  retval.xdata (j) = static_cast<Complex *>(X->x)[j];
                }

              BEGIN_INTERRUPT_IMMEDIATELY_IN_FOREIGN_CODE;
              CHOLMOD_NAME(free_sparse) (&X, cm);
              CHOLMOD_NAME(free_factor) (&L, cm);
              CHOLMOD_NAME(finish) (cm);
              static char tmp[] = " ";
              CHOLMOD_NAME(print_common) (tmp, cm);
              END_INTERRUPT_IMMEDIATELY_IN_FOREIGN_CODE;
            }
#else
          (*current_liboctave_warning_handler)
            ("CHOLMOD not installed");

          mattype.mark_as_unsymmetric ();
          typ = MatrixType::Full;
#endif
        }

      if (typ == MatrixType::Full)
        {
#ifdef HAVE_UMFPACK
          Matrix Control, Info;
          void *Numeric = factorize (err, rcond, Control, Info,
                                     sing_handler, calc_cond);

          if (err == 0)
            {
              octave_idx_type b_nr = b.rows ();
              octave_idx_type b_nc = b.cols ();
              int status = 0;
              double *control = Control.fortran_vec ();
              double *info = Info.fortran_vec ();
              const octave_idx_type *Ap = cidx ();
              const octave_idx_type *Ai = ridx ();
              const Complex *Ax = data ();

#ifdef UMFPACK_SEPARATE_SPLIT
              OCTAVE_LOCAL_BUFFER (double, Bx, b_nr);
              OCTAVE_LOCAL_BUFFER (double, Bz, b_nr);
              for (octave_idx_type i = 0; i < b_nr; i++)
                Bz[i] = 0.;
#else
              OCTAVE_LOCAL_BUFFER (Complex, Bz, b_nr);
#endif

              // Take a first guess that the number of non-zero terms
              // will be as many as in b
              octave_idx_type x_nz = b.nnz ();
              octave_idx_type ii = 0;
              retval = SparseComplexMatrix (b_nr, b_nc, x_nz);

              OCTAVE_LOCAL_BUFFER (Complex, Xx, b_nr);

              retval.xcidx (0) = 0;
              for (octave_idx_type j = 0; j < b_nc; j++)
                {

#ifdef UMFPACK_SEPARATE_SPLIT
                  for (octave_idx_type i = 0; i < b_nr; i++)
                    Bx[i] = b.elem (i, j);

                  status = UMFPACK_ZNAME (solve) (UMFPACK_A, Ap,
                                             Ai,
                                             reinterpret_cast<const double *> (Ax),
                                             0,
                                             reinterpret_cast<double *> (Xx),
                                             0,
                                             Bx, Bz, Numeric, control,
                                             info);
#else
                  for (octave_idx_type i = 0; i < b_nr; i++)
                    Bz[i] = b.elem (i, j);

                  status = UMFPACK_ZNAME (solve) (UMFPACK_A, Ap, Ai,
                                             reinterpret_cast<const double *> (Ax),
                                             0,
                                             reinterpret_cast<double *> (Xx),
                                             0,
                                             reinterpret_cast<double *> (Bz),
                                             0,
                                             Numeric, control,
                                             info);
#endif
                  if (status < 0)
                    {
                      (*current_liboctave_error_handler)
                        ("SparseComplexMatrix::solve solve failed");

                      UMFPACK_ZNAME (report_status) (control, status);

                      err = -1;

                      break;
                    }

                  for (octave_idx_type i = 0; i < b_nr; i++)
                    {
                      Complex tmp = Xx[i];
                      if (tmp != 0.0)
                        {
                          if (ii == x_nz)
                            {
                              // Resize the sparse matrix
                              octave_idx_type sz = x_nz * (b_nc - j) / b_nc;
                              sz = (sz > 10 ? sz : 10) + x_nz;
                              retval.change_capacity (sz);
                              x_nz = sz;
                            }
                          retval.xdata (ii) = tmp;
                          retval.xridx (ii++) = i;
                        }
                    }
                  retval.xcidx (j+1) = ii;
                }

              retval.maybe_compress ();

              UMFPACK_ZNAME (report_info) (control, info);

              UMFPACK_ZNAME (free_numeric) (&Numeric);
            }
          else
            mattype.mark_as_rectangular ();

#else
          (*current_liboctave_error_handler) ("UMFPACK not installed");
#endif
        }
      else if (typ != MatrixType::Hermitian)
        (*current_liboctave_error_handler) ("incorrect matrix type");
    }

  return retval;
}

ComplexMatrix
SparseComplexMatrix::fsolve (MatrixType &mattype, const ComplexMatrix& b,
                             octave_idx_type& err, double& rcond,
                             solve_singularity_handler sing_handler,
                             bool calc_cond) const
{
  ComplexMatrix retval;

  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();
  err = 0;

  if (nr != nc || nr != b.rows ())
    (*current_liboctave_error_handler)
      ("matrix dimension mismatch solution of linear equations");
  else if (nr == 0 || b.cols () == 0)
    retval = ComplexMatrix (nc, b.cols (), Complex (0.0, 0.0));
  else
    {
      // Print spparms("spumoni") info if requested
      volatile int typ = mattype.type ();
      mattype.info ();

      if (typ == MatrixType::Hermitian)
        {
#ifdef HAVE_CHOLMOD
          cholmod_common Common;
          cholmod_common *cm = &Common;

          // Setup initial parameters
          CHOLMOD_NAME(start) (cm);
          cm->prefer_zomplex = false;

          double spu = octave_sparse_params::get_key ("spumoni");
          if (spu == 0.)
            {
              cm->print = -1;
              cm->print_function = 0;
            }
          else
            {
              cm->print = static_cast<int> (spu) + 2;
              cm->print_function =&SparseCholPrint;
            }

          cm->error_handler = &SparseCholError;
          cm->complex_divide = CHOLMOD_NAME(divcomplex);
          cm->hypotenuse = CHOLMOD_NAME(hypot);

          cm->final_ll = true;

          cholmod_sparse Astore;
          cholmod_sparse *A = &Astore;
          double dummy;
          A->nrow = nr;
          A->ncol = nc;

          A->p = cidx ();
          A->i = ridx ();
          A->nzmax = nnz ();
          A->packed = true;
          A->sorted = true;
          A->nz = 0;
#ifdef USE_64_BIT_IDX_T
          A->itype = CHOLMOD_LONG;
#else
          A->itype = CHOLMOD_INT;
#endif
          A->dtype = CHOLMOD_DOUBLE;
          A->stype = 1;
          A->xtype = CHOLMOD_COMPLEX;

          if (nr < 1)
            A->x = &dummy;
          else
            A->x = data ();

          cholmod_dense Bstore;
          cholmod_dense *B = &Bstore;
          B->nrow = b.rows ();
          B->ncol = b.cols ();
          B->d = B->nrow;
          B->nzmax = B->nrow * B->ncol;
          B->dtype = CHOLMOD_DOUBLE;
          B->xtype = CHOLMOD_COMPLEX;
          if (nc < 1 || b.cols () < 1)
            B->x = &dummy;
          else
            // We won't alter it, honest :-)
            B->x = const_cast<Complex *>(b.fortran_vec ());

          cholmod_factor *L;
          BEGIN_INTERRUPT_IMMEDIATELY_IN_FOREIGN_CODE;
          L = CHOLMOD_NAME(analyze) (A, cm);
          CHOLMOD_NAME(factorize) (A, L, cm);
          if (calc_cond)
            rcond = CHOLMOD_NAME(rcond)(L, cm);
          else
            rcond = 1.;
          END_INTERRUPT_IMMEDIATELY_IN_FOREIGN_CODE;

          if (rcond == 0.0)
            {
              // Either its indefinite or singular. Try UMFPACK
              mattype.mark_as_unsymmetric ();
              typ = MatrixType::Full;
            }
          else
            {
              volatile double rcond_plus_one = rcond + 1.0;

              if (rcond_plus_one == 1.0 || xisnan (rcond))
                {
                  err = -2;

                  if (sing_handler)
                    {
                      sing_handler (rcond);
                      mattype.mark_as_rectangular ();
                    }
                  else
                    (*current_liboctave_error_handler)
                      ("SparseMatrix::solve matrix singular to machine precision, rcond = %g",
                       rcond);

                  return retval;
                }

              cholmod_dense *X;
              BEGIN_INTERRUPT_IMMEDIATELY_IN_FOREIGN_CODE;
              X = CHOLMOD_NAME(solve) (CHOLMOD_A, L, B, cm);
              END_INTERRUPT_IMMEDIATELY_IN_FOREIGN_CODE;

              retval.resize (b.rows (), b.cols ());
              for (octave_idx_type j = 0; j < b.cols (); j++)
                {
                  octave_idx_type jr = j * b.rows ();
                  for (octave_idx_type i = 0; i < b.rows (); i++)
                    retval.xelem (i,j) = static_cast<Complex *>(X->x)[jr + i];
                }

              BEGIN_INTERRUPT_IMMEDIATELY_IN_FOREIGN_CODE;
              CHOLMOD_NAME(free_dense) (&X, cm);
              CHOLMOD_NAME(free_factor) (&L, cm);
              CHOLMOD_NAME(finish) (cm);
              static char tmp[] = " ";
              CHOLMOD_NAME(print_common) (tmp, cm);
              END_INTERRUPT_IMMEDIATELY_IN_FOREIGN_CODE;
            }
#else
          (*current_liboctave_warning_handler)
            ("CHOLMOD not installed");

          mattype.mark_as_unsymmetric ();
          typ = MatrixType::Full;
#endif
        }

      if (typ == MatrixType::Full)
        {
#ifdef HAVE_UMFPACK
          Matrix Control, Info;
          void *Numeric = factorize (err, rcond, Control, Info,
                                     sing_handler, calc_cond);

          if (err == 0)
            {
              octave_idx_type b_nr = b.rows ();
              octave_idx_type b_nc = b.cols ();
              int status = 0;
              double *control = Control.fortran_vec ();
              double *info = Info.fortran_vec ();
              const octave_idx_type *Ap = cidx ();
              const octave_idx_type *Ai = ridx ();
              const Complex *Ax = data ();
              const Complex *Bx = b.fortran_vec ();

              retval.resize (b_nr, b_nc);
              Complex *Xx = retval.fortran_vec ();

              for (octave_idx_type j = 0, iidx = 0; j < b_nc; j++, iidx += b_nr)
                {
                  status =
                    UMFPACK_ZNAME (solve) (UMFPACK_A, Ap, Ai,
                                      reinterpret_cast<const double *> (Ax),
                                      0,
                                      reinterpret_cast<double *> (&Xx[iidx]),
                                      0,
                                      reinterpret_cast<const double *> (&Bx[iidx]),
                                      0, Numeric, control, info);

                  if (status < 0)
                    {
                      (*current_liboctave_error_handler)
                        ("SparseComplexMatrix::solve solve failed");

                      UMFPACK_ZNAME (report_status) (control, status);

                      err = -1;

                      break;
                    }
                }

              UMFPACK_ZNAME (report_info) (control, info);

              UMFPACK_ZNAME (free_numeric) (&Numeric);
            }
          else
            mattype.mark_as_rectangular ();

#else
          (*current_liboctave_error_handler) ("UMFPACK not installed");
#endif
        }
      else if (typ != MatrixType::Hermitian)
        (*current_liboctave_error_handler) ("incorrect matrix type");
    }

  return retval;
}

SparseComplexMatrix
SparseComplexMatrix::fsolve (MatrixType &mattype, const SparseComplexMatrix& b,
                             octave_idx_type& err, double& rcond,
                             solve_singularity_handler sing_handler,
                             bool calc_cond) const
{
  SparseComplexMatrix retval;

  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();
  err = 0;

  if (nr != nc || nr != b.rows ())
    (*current_liboctave_error_handler)
      ("matrix dimension mismatch solution of linear equations");
  else if (nr == 0 || b.cols () == 0)
    retval = SparseComplexMatrix (nc, b.cols ());
  else
    {
      // Print spparms("spumoni") info if requested
      volatile int typ = mattype.type ();
      mattype.info ();

      if (typ == MatrixType::Hermitian)
        {
#ifdef HAVE_CHOLMOD
          cholmod_common Common;
          cholmod_common *cm = &Common;

          // Setup initial parameters
          CHOLMOD_NAME(start) (cm);
          cm->prefer_zomplex = false;

          double spu = octave_sparse_params::get_key ("spumoni");
          if (spu == 0.)
            {
              cm->print = -1;
              cm->print_function = 0;
            }
          else
            {
              cm->print = static_cast<int> (spu) + 2;
              cm->print_function =&SparseCholPrint;
            }

          cm->error_handler = &SparseCholError;
          cm->complex_divide = CHOLMOD_NAME(divcomplex);
          cm->hypotenuse = CHOLMOD_NAME(hypot);

          cm->final_ll = true;

          cholmod_sparse Astore;
          cholmod_sparse *A = &Astore;
          double dummy;
          A->nrow = nr;
          A->ncol = nc;

          A->p = cidx ();
          A->i = ridx ();
          A->nzmax = nnz ();
          A->packed = true;
          A->sorted = true;
          A->nz = 0;
#ifdef USE_64_BIT_IDX_T
          A->itype = CHOLMOD_LONG;
#else
          A->itype = CHOLMOD_INT;
#endif
          A->dtype = CHOLMOD_DOUBLE;
          A->stype = 1;
          A->xtype = CHOLMOD_COMPLEX;

          if (nr < 1)
            A->x = &dummy;
          else
            A->x = data ();

          cholmod_sparse Bstore;
          cholmod_sparse *B = &Bstore;
          B->nrow = b.rows ();
          B->ncol = b.cols ();
          B->p = b.cidx ();
          B->i = b.ridx ();
          B->nzmax = b.nnz ();
          B->packed = true;
          B->sorted = true;
          B->nz = 0;
#ifdef USE_64_BIT_IDX_T
          B->itype = CHOLMOD_LONG;
#else
          B->itype = CHOLMOD_INT;
#endif
          B->dtype = CHOLMOD_DOUBLE;
          B->stype = 0;
          B->xtype = CHOLMOD_COMPLEX;

          if (b.rows () < 1 || b.cols () < 1)
            B->x = &dummy;
          else
            B->x = b.data ();

          cholmod_factor *L;
          BEGIN_INTERRUPT_IMMEDIATELY_IN_FOREIGN_CODE;
          L = CHOLMOD_NAME(analyze) (A, cm);
          CHOLMOD_NAME(factorize) (A, L, cm);
          if (calc_cond)
            rcond = CHOLMOD_NAME(rcond)(L, cm);
          else
            rcond = 1.;
          END_INTERRUPT_IMMEDIATELY_IN_FOREIGN_CODE;

          if (rcond == 0.0)
            {
              // Either its indefinite or singular. Try UMFPACK
              mattype.mark_as_unsymmetric ();
              typ = MatrixType::Full;
            }
          else
            {
              volatile double rcond_plus_one = rcond + 1.0;

              if (rcond_plus_one == 1.0 || xisnan (rcond))
                {
                  err = -2;

                  if (sing_handler)
                    {
                      sing_handler (rcond);
                      mattype.mark_as_rectangular ();
                    }
                  else
                    (*current_liboctave_error_handler)
                      ("SparseMatrix::solve matrix singular to machine precision, rcond = %g",
                       rcond);

                  return retval;
                }

              cholmod_sparse *X;
              BEGIN_INTERRUPT_IMMEDIATELY_IN_FOREIGN_CODE;
              X = CHOLMOD_NAME(spsolve) (CHOLMOD_A, L, B, cm);
              END_INTERRUPT_IMMEDIATELY_IN_FOREIGN_CODE;

              retval = SparseComplexMatrix
                (static_cast<octave_idx_type>(X->nrow),
                 static_cast<octave_idx_type>(X->ncol),
                 static_cast<octave_idx_type>(X->nzmax));
              for (octave_idx_type j = 0;
                   j <= static_cast<octave_idx_type>(X->ncol); j++)
                retval.xcidx (j) = static_cast<octave_idx_type *>(X->p)[j];
              for (octave_idx_type j = 0;
                   j < static_cast<octave_idx_type>(X->nzmax); j++)
                {
                  retval.xridx (j) = static_cast<octave_idx_type *>(X->i)[j];
                  retval.xdata (j) = static_cast<Complex *>(X->x)[j];
                }

              BEGIN_INTERRUPT_IMMEDIATELY_IN_FOREIGN_CODE;
              CHOLMOD_NAME(free_sparse) (&X, cm);
              CHOLMOD_NAME(free_factor) (&L, cm);
              CHOLMOD_NAME(finish) (cm);
              static char tmp[] = " ";
              CHOLMOD_NAME(print_common) (tmp, cm);
              END_INTERRUPT_IMMEDIATELY_IN_FOREIGN_CODE;
            }
#else
          (*current_liboctave_warning_handler)
            ("CHOLMOD not installed");

          mattype.mark_as_unsymmetric ();
          typ = MatrixType::Full;
#endif
        }

      if (typ == MatrixType::Full)
        {
#ifdef HAVE_UMFPACK
          Matrix Control, Info;
          void *Numeric = factorize (err, rcond, Control, Info,
                                     sing_handler, calc_cond);

          if (err == 0)
            {
              octave_idx_type b_nr = b.rows ();
              octave_idx_type b_nc = b.cols ();
              int status = 0;
              double *control = Control.fortran_vec ();
              double *info = Info.fortran_vec ();
              const octave_idx_type *Ap = cidx ();
              const octave_idx_type *Ai = ridx ();
              const Complex *Ax = data ();

              OCTAVE_LOCAL_BUFFER (Complex, Bx, b_nr);

              // Take a first guess that the number of non-zero terms
              // will be as many as in b
              octave_idx_type x_nz = b.nnz ();
              octave_idx_type ii = 0;
              retval = SparseComplexMatrix (b_nr, b_nc, x_nz);

              OCTAVE_LOCAL_BUFFER (Complex, Xx, b_nr);

              retval.xcidx (0) = 0;
              for (octave_idx_type j = 0; j < b_nc; j++)
                {
                  for (octave_idx_type i = 0; i < b_nr; i++)
                    Bx[i] = b (i,j);

                  status = UMFPACK_ZNAME (solve) (UMFPACK_A, Ap,
                                             Ai,
                                             reinterpret_cast<const double *> (Ax),
                                             0,
                                             reinterpret_cast<double *> (Xx),
                                             0,
                                             reinterpret_cast<double *> (Bx),
                                             0, Numeric, control, info);

                  if (status < 0)
                    {
                      (*current_liboctave_error_handler)
                        ("SparseComplexMatrix::solve solve failed");

                      UMFPACK_ZNAME (report_status) (control, status);

                      err = -1;

                      break;
                    }

                  for (octave_idx_type i = 0; i < b_nr; i++)
                    {
                      Complex tmp = Xx[i];
                      if (tmp != 0.0)
                        {
                          if (ii == x_nz)
                            {
                              // Resize the sparse matrix
                              octave_idx_type sz = x_nz * (b_nc - j) / b_nc;
                              sz = (sz > 10 ? sz : 10) + x_nz;
                              retval.change_capacity (sz);
                              x_nz = sz;
                            }
                          retval.xdata (ii) = tmp;
                          retval.xridx (ii++) = i;
                        }
                    }
                  retval.xcidx (j+1) = ii;
                }

              retval.maybe_compress ();

              rcond = Info (UMFPACK_RCOND);
              volatile double rcond_plus_one = rcond + 1.0;

              if (status == UMFPACK_WARNING_singular_matrix ||
                  rcond_plus_one == 1.0 || xisnan (rcond))
                {
                  err = -2;

                  if (sing_handler)
                    sing_handler (rcond);
                  else
                    (*current_liboctave_error_handler)
                      ("SparseComplexMatrix::solve matrix singular to machine precision, rcond = %g",
                       rcond);

                }

              UMFPACK_ZNAME (report_info) (control, info);

              UMFPACK_ZNAME (free_numeric) (&Numeric);
            }
          else
            mattype.mark_as_rectangular ();

#else
          (*current_liboctave_error_handler) ("UMFPACK not installed");
#endif
        }
      else if (typ != MatrixType::Hermitian)
        (*current_liboctave_error_handler) ("incorrect matrix type");
    }

  return retval;
}

ComplexMatrix
SparseComplexMatrix::solve (MatrixType &mattype, const Matrix& b) const
{
  octave_idx_type info;
  double rcond;
  return solve (mattype, b, info, rcond, 0);
}

ComplexMatrix
SparseComplexMatrix::solve (MatrixType &mattype, const Matrix& b,
                            octave_idx_type& info) const
{
  double rcond;
  return solve (mattype, b, info, rcond, 0);
}

ComplexMatrix
SparseComplexMatrix::solve (MatrixType &mattype, const Matrix& b,
                            octave_idx_type& info, double& rcond) const
{
  return solve (mattype, b, info, rcond, 0);
}

ComplexMatrix
SparseComplexMatrix::solve (MatrixType &mattype, const Matrix& b,
                            octave_idx_type& err, double& rcond,
                            solve_singularity_handler sing_handler,
                            bool singular_fallback) const
{
  ComplexMatrix retval;
  int typ = mattype.type (false);

  if (typ == MatrixType::Unknown)
    typ = mattype.type (*this);

  if (typ == MatrixType::Diagonal || typ == MatrixType::Permuted_Diagonal)
    retval = dsolve (mattype, b, err, rcond, sing_handler, false);
  else if (typ == MatrixType::Upper || typ == MatrixType::Permuted_Upper)
    retval = utsolve (mattype, b, err, rcond, sing_handler, false);
  else if (typ == MatrixType::Lower || typ == MatrixType::Permuted_Lower)
    retval = ltsolve (mattype, b, err, rcond, sing_handler, false);
  else if (typ == MatrixType::Banded || typ == MatrixType::Banded_Hermitian)
    retval = bsolve (mattype, b, err, rcond, sing_handler, false);
  else if (typ == MatrixType::Tridiagonal ||
           typ == MatrixType::Tridiagonal_Hermitian)
    retval = trisolve (mattype, b, err, rcond, sing_handler, false);
  else if (typ == MatrixType::Full || typ == MatrixType::Hermitian)
    retval = fsolve (mattype, b, err, rcond, sing_handler, true);
  else if (typ != MatrixType::Rectangular)
    {
      (*current_liboctave_error_handler) ("unknown matrix type");
      return ComplexMatrix ();
    }

  if (singular_fallback && mattype.type (false) == MatrixType::Rectangular)
    {
      rcond = 1.;
#ifdef USE_QRSOLVE
      retval = qrsolve (*this, b, err);
#else
      retval = dmsolve<ComplexMatrix, SparseComplexMatrix,
        Matrix> (*this, b, err);
#endif
    }

  return retval;
}

SparseComplexMatrix
SparseComplexMatrix::solve (MatrixType &mattype, const SparseMatrix& b) const
{
  octave_idx_type info;
  double rcond;
  return solve (mattype, b, info, rcond, 0);
}

SparseComplexMatrix
SparseComplexMatrix::solve (MatrixType &mattype, const SparseMatrix& b,
                     octave_idx_type& info) const
{
  double rcond;
  return solve (mattype, b, info, rcond, 0);
}

SparseComplexMatrix
SparseComplexMatrix::solve (MatrixType &mattype, const SparseMatrix& b,
                     octave_idx_type& info, double& rcond) const
{
  return solve (mattype, b, info, rcond, 0);
}

SparseComplexMatrix
SparseComplexMatrix::solve (MatrixType &mattype, const SparseMatrix& b,
                            octave_idx_type& err, double& rcond,
                            solve_singularity_handler sing_handler,
                            bool singular_fallback) const
{
  SparseComplexMatrix retval;
  int typ = mattype.type (false);

  if (typ == MatrixType::Unknown)
    typ = mattype.type (*this);

  if (typ == MatrixType::Diagonal || typ == MatrixType::Permuted_Diagonal)
    retval = dsolve (mattype, b, err, rcond, sing_handler, false);
  else if (typ == MatrixType::Upper || typ == MatrixType::Permuted_Upper)
    retval = utsolve (mattype, b, err, rcond, sing_handler, false);
  else if (typ == MatrixType::Lower || typ == MatrixType::Permuted_Lower)
    retval = ltsolve (mattype, b, err, rcond, sing_handler, false);
  else if (typ == MatrixType::Banded || typ == MatrixType::Banded_Hermitian)
    retval = bsolve (mattype, b, err, rcond, sing_handler, false);
  else if (typ == MatrixType::Tridiagonal ||
           typ == MatrixType::Tridiagonal_Hermitian)
    retval = trisolve (mattype, b, err, rcond, sing_handler, false);
  else if (typ == MatrixType::Full || typ == MatrixType::Hermitian)
    retval = fsolve (mattype, b, err, rcond, sing_handler, true);
  else if (typ != MatrixType::Rectangular)
    {
      (*current_liboctave_error_handler) ("unknown matrix type");
      return SparseComplexMatrix ();
    }

  if (singular_fallback && mattype.type (false) == MatrixType::Rectangular)
    {
      rcond = 1.;
#ifdef USE_QRSOLVE
      retval = qrsolve (*this, b, err);
#else
      retval = dmsolve<SparseComplexMatrix, SparseComplexMatrix,
        SparseMatrix> (*this, b, err);
#endif
    }

  return retval;
}

ComplexMatrix
SparseComplexMatrix::solve (MatrixType &mattype, const ComplexMatrix& b) const
{
  octave_idx_type info;
  double rcond;
  return solve (mattype, b, info, rcond, 0);
}

ComplexMatrix
SparseComplexMatrix::solve (MatrixType &mattype, const ComplexMatrix& b,
                            octave_idx_type& info) const
{
  double rcond;
  return solve (mattype, b, info, rcond, 0);
}

ComplexMatrix
SparseComplexMatrix::solve (MatrixType &mattype, const ComplexMatrix& b,
                            octave_idx_type& info, double& rcond) const
{
  return solve (mattype, b, info, rcond, 0);
}

ComplexMatrix
SparseComplexMatrix::solve (MatrixType &mattype, const ComplexMatrix& b,
                            octave_idx_type& err, double& rcond,
                            solve_singularity_handler sing_handler,
                            bool singular_fallback) const
{
  ComplexMatrix retval;
  int typ = mattype.type (false);

  if (typ == MatrixType::Unknown)
    typ = mattype.type (*this);

  if (typ == MatrixType::Diagonal || typ == MatrixType::Permuted_Diagonal)
    retval = dsolve (mattype, b, err, rcond, sing_handler, false);
  else if (typ == MatrixType::Upper || typ == MatrixType::Permuted_Upper)
    retval = utsolve (mattype, b, err, rcond, sing_handler, false);
  else if (typ == MatrixType::Lower || typ == MatrixType::Permuted_Lower)
    retval = ltsolve (mattype, b, err, rcond, sing_handler, false);
  else if (typ == MatrixType::Banded || typ == MatrixType::Banded_Hermitian)
    retval = bsolve (mattype, b, err, rcond, sing_handler, false);
  else if (typ == MatrixType::Tridiagonal ||
           typ == MatrixType::Tridiagonal_Hermitian)
    retval = trisolve (mattype, b, err, rcond, sing_handler, false);
  else if (typ == MatrixType::Full || typ == MatrixType::Hermitian)
    retval = fsolve (mattype, b, err, rcond, sing_handler, true);
  else if (typ != MatrixType::Rectangular)
    {
      (*current_liboctave_error_handler) ("unknown matrix type");
      return ComplexMatrix ();
    }

  if (singular_fallback && mattype.type (false) == MatrixType::Rectangular)
    {
      rcond = 1.;
#ifdef USE_QRSOLVE
      retval = qrsolve (*this, b, err);
#else
      retval = dmsolve<ComplexMatrix, SparseComplexMatrix,
        ComplexMatrix> (*this, b, err);
#endif
    }

  return retval;
}

SparseComplexMatrix
SparseComplexMatrix::solve (MatrixType &mattype,
                            const SparseComplexMatrix& b) const
{
  octave_idx_type info;
  double rcond;
  return solve (mattype, b, info, rcond, 0);
}

SparseComplexMatrix
SparseComplexMatrix::solve (MatrixType &mattype, const SparseComplexMatrix& b,
                            octave_idx_type& info) const
{
  double rcond;
  return solve (mattype, b, info, rcond, 0);
}

SparseComplexMatrix
SparseComplexMatrix::solve (MatrixType &mattype, const SparseComplexMatrix& b,
                            octave_idx_type& info, double& rcond) const
{
  return solve (mattype, b, info, rcond, 0);
}

SparseComplexMatrix
SparseComplexMatrix::solve (MatrixType &mattype, const SparseComplexMatrix& b,
                            octave_idx_type& err, double& rcond,
                            solve_singularity_handler sing_handler,
                            bool singular_fallback) const
{
  SparseComplexMatrix retval;
  int typ = mattype.type (false);

  if (typ == MatrixType::Unknown)
    typ = mattype.type (*this);

  if (typ == MatrixType::Diagonal || typ == MatrixType::Permuted_Diagonal)
    retval = dsolve (mattype, b, err, rcond, sing_handler, false);
  else if (typ == MatrixType::Upper || typ == MatrixType::Permuted_Upper)
    retval = utsolve (mattype, b, err, rcond, sing_handler, false);
  else if (typ == MatrixType::Lower || typ == MatrixType::Permuted_Lower)
    retval = ltsolve (mattype, b, err, rcond, sing_handler, false);
  else if (typ == MatrixType::Banded || typ == MatrixType::Banded_Hermitian)
    retval = bsolve (mattype, b, err, rcond, sing_handler, false);
  else if (typ == MatrixType::Tridiagonal ||
           typ == MatrixType::Tridiagonal_Hermitian)
    retval = trisolve (mattype, b, err, rcond, sing_handler, false);
  else if (typ == MatrixType::Full || typ == MatrixType::Hermitian)
    retval = fsolve (mattype, b, err, rcond, sing_handler, true);
  else if (typ != MatrixType::Rectangular)
    {
      (*current_liboctave_error_handler) ("unknown matrix type");
      return SparseComplexMatrix ();
    }

  if (singular_fallback && mattype.type (false) == MatrixType::Rectangular)
    {
      rcond = 1.;
#ifdef USE_QRSOLVE
      retval = qrsolve (*this, b, err);
#else
      retval = dmsolve<SparseComplexMatrix, SparseComplexMatrix,
        SparseComplexMatrix> (*this, b, err);
#endif
    }

  return retval;
}

ComplexColumnVector
SparseComplexMatrix::solve (MatrixType &mattype, const ColumnVector& b) const
{
  octave_idx_type info; double rcond;
  return solve (mattype, b, info, rcond);
}

ComplexColumnVector
SparseComplexMatrix::solve (MatrixType &mattype, const ColumnVector& b,
                            octave_idx_type& info) const
{
  double rcond;
  return solve (mattype, b, info, rcond);
}

ComplexColumnVector
SparseComplexMatrix::solve (MatrixType &mattype, const ColumnVector& b,
                            octave_idx_type& info, double& rcond) const
{
  return solve (mattype, b, info, rcond, 0);
}

ComplexColumnVector
SparseComplexMatrix::solve (MatrixType &mattype, const ColumnVector& b,
                            octave_idx_type& info, double& rcond,
                            solve_singularity_handler sing_handler) const
{
  Matrix tmp (b);
  return solve (mattype, tmp, info, rcond, sing_handler).column (static_cast<octave_idx_type> (0));
}

ComplexColumnVector
SparseComplexMatrix::solve (MatrixType &mattype,
                            const ComplexColumnVector& b) const
{
  octave_idx_type info;
  double rcond;
  return solve (mattype, b, info, rcond, 0);
}

ComplexColumnVector
SparseComplexMatrix::solve (MatrixType &mattype, const ComplexColumnVector& b,
                            octave_idx_type& info) const
{
  double rcond;
  return solve (mattype, b, info, rcond, 0);
}

ComplexColumnVector
SparseComplexMatrix::solve (MatrixType &mattype, const ComplexColumnVector& b,
                            octave_idx_type& info, double& rcond) const
{
  return solve (mattype, b, info, rcond, 0);
}

ComplexColumnVector
SparseComplexMatrix::solve (MatrixType &mattype, const ComplexColumnVector& b,
                            octave_idx_type& info, double& rcond,
                            solve_singularity_handler sing_handler) const
{
  ComplexMatrix tmp (b);
  return solve (mattype, tmp, info, rcond, sing_handler).column (static_cast<octave_idx_type> (0));
}

ComplexMatrix
SparseComplexMatrix::solve (const Matrix& b) const
{
  octave_idx_type info;
  double rcond;
  return solve (b, info, rcond, 0);
}

ComplexMatrix
SparseComplexMatrix::solve (const Matrix& b, octave_idx_type& info) const
{
  double rcond;
  return solve (b, info, rcond, 0);
}

ComplexMatrix
SparseComplexMatrix::solve (const Matrix& b, octave_idx_type& info,
                     double& rcond) const
{
  return solve (b, info, rcond, 0);
}

ComplexMatrix
SparseComplexMatrix::solve (const Matrix& b, octave_idx_type& err,
                            double& rcond,
                            solve_singularity_handler sing_handler) const
{
  MatrixType mattype (*this);
  return solve (mattype, b, err, rcond, sing_handler);
}

SparseComplexMatrix
SparseComplexMatrix::solve (const SparseMatrix& b) const
{
  octave_idx_type info;
  double rcond;
  return solve (b, info, rcond, 0);
}

SparseComplexMatrix
SparseComplexMatrix::solve (const SparseMatrix& b,
                     octave_idx_type& info) const
{
  double rcond;
  return solve (b, info, rcond, 0);
}

SparseComplexMatrix
SparseComplexMatrix::solve (const SparseMatrix& b,
                     octave_idx_type& info, double& rcond) const
{
  return solve (b, info, rcond, 0);
}

SparseComplexMatrix
SparseComplexMatrix::solve (const SparseMatrix& b,
                     octave_idx_type& err, double& rcond,
                     solve_singularity_handler sing_handler) const
{
  MatrixType mattype (*this);
  return solve (mattype, b, err, rcond, sing_handler);
}

ComplexMatrix
SparseComplexMatrix::solve (const ComplexMatrix& b,
                            octave_idx_type& info) const
{
  double rcond;
  return solve (b, info, rcond, 0);
}

ComplexMatrix
SparseComplexMatrix::solve (const ComplexMatrix& b,
                     octave_idx_type& info, double& rcond) const
{
  return solve (b, info, rcond, 0);
}

ComplexMatrix
SparseComplexMatrix::solve (const ComplexMatrix& b,
                     octave_idx_type& err, double& rcond,
                     solve_singularity_handler sing_handler) const
{
  MatrixType mattype (*this);
  return solve (mattype, b, err, rcond, sing_handler);
}

SparseComplexMatrix
SparseComplexMatrix::solve (const SparseComplexMatrix& b) const
{
  octave_idx_type info;
  double rcond;
  return solve (b, info, rcond, 0);
}

SparseComplexMatrix
SparseComplexMatrix::solve (const SparseComplexMatrix& b,
                     octave_idx_type& info) const
{
  double rcond;
  return solve (b, info, rcond, 0);
}

SparseComplexMatrix
SparseComplexMatrix::solve (const SparseComplexMatrix& b,
                     octave_idx_type& info, double& rcond) const
{
  return solve (b, info, rcond, 0);
}

SparseComplexMatrix
SparseComplexMatrix::solve (const SparseComplexMatrix& b,
                     octave_idx_type& err, double& rcond,
                     solve_singularity_handler sing_handler) const
{
  MatrixType mattype (*this);
  return solve (mattype, b, err, rcond, sing_handler);
}

ComplexColumnVector
SparseComplexMatrix::solve (const ColumnVector& b) const
{
  octave_idx_type info; double rcond;
  return solve (b, info, rcond);
}

ComplexColumnVector
SparseComplexMatrix::solve (const ColumnVector& b, octave_idx_type& info) const
{
  double rcond;
  return solve (b, info, rcond);
}

ComplexColumnVector
SparseComplexMatrix::solve (const ColumnVector& b, octave_idx_type& info,
                            double& rcond) const
{
  return solve (b, info, rcond, 0);
}

ComplexColumnVector
SparseComplexMatrix::solve (const ColumnVector& b, octave_idx_type& info, double& rcond,
                            solve_singularity_handler sing_handler) const
{
  Matrix tmp (b);
  return solve (tmp, info, rcond, sing_handler).column (static_cast<octave_idx_type> (0));
}

ComplexColumnVector
SparseComplexMatrix::solve (const ComplexColumnVector& b) const
{
  octave_idx_type info;
  double rcond;
  return solve (b, info, rcond, 0);
}

ComplexColumnVector
SparseComplexMatrix::solve (const ComplexColumnVector& b, octave_idx_type& info) const
{
  double rcond;
  return solve (b, info, rcond, 0);
}

ComplexColumnVector
SparseComplexMatrix::solve (const ComplexColumnVector& b, octave_idx_type& info,
                     double& rcond) const
{
  return solve (b, info, rcond, 0);
}

ComplexColumnVector
SparseComplexMatrix::solve (const ComplexColumnVector& b, octave_idx_type& info,
                            double& rcond,
                            solve_singularity_handler sing_handler) const
{
  ComplexMatrix tmp (b);
  return solve (tmp, info, rcond, sing_handler).column (static_cast<octave_idx_type> (0));
}

// unary operations
SparseBoolMatrix
SparseComplexMatrix::operator ! (void) const
{
  if (any_element_is_nan ())
    gripe_nan_to_logical_conversion ();

  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();
  octave_idx_type nz1 = nnz ();
  octave_idx_type nz2 = nr*nc - nz1;

  SparseBoolMatrix r (nr, nc, nz2);

  octave_idx_type ii = 0;
  octave_idx_type jj = 0;
  r.cidx (0) = 0;
  for (octave_idx_type i = 0; i < nc; i++)
    {
      for (octave_idx_type j = 0; j < nr; j++)
        {
          if (jj < cidx (i+1) && ridx (jj) == j)
            jj++;
          else
            {
              r.data (ii) = true;
              r.ridx (ii++) = j;
            }
        }
      r.cidx (i+1) = ii;
    }

  return r;
}

SparseComplexMatrix
SparseComplexMatrix::squeeze (void) const
{
  return MSparse<Complex>::squeeze ();
}

SparseComplexMatrix
SparseComplexMatrix::reshape (const dim_vector& new_dims) const
{
  return MSparse<Complex>::reshape (new_dims);
}

SparseComplexMatrix
SparseComplexMatrix::permute (const Array<octave_idx_type>& vec, bool inv) const
{
  return MSparse<Complex>::permute (vec, inv);
}

SparseComplexMatrix
SparseComplexMatrix::ipermute (const Array<octave_idx_type>& vec) const
{
  return MSparse<Complex>::ipermute (vec);
}

// other operations

bool
SparseComplexMatrix::any_element_is_nan (void) const
{
  octave_idx_type nel = nnz ();

  for (octave_idx_type i = 0; i < nel; i++)
    {
      Complex val = data (i);
      if (xisnan (val))
        return true;
    }

  return false;
}

bool
SparseComplexMatrix::any_element_is_inf_or_nan (void) const
{
  octave_idx_type nel = nnz ();

  for (octave_idx_type i = 0; i < nel; i++)
    {
      Complex val = data (i);
      if (xisinf (val) || xisnan (val))
        return true;
    }

  return false;
}

// Return true if no elements have imaginary components.

bool
SparseComplexMatrix::all_elements_are_real (void) const
{
  return mx_inline_all_real (nnz (), data ());
}

// Return nonzero if any element of CM has a non-integer real or
// imaginary part.  Also extract the largest and smallest (real or
// imaginary) values and return them in MAX_VAL and MIN_VAL.

bool
SparseComplexMatrix::all_integers (double& max_val, double& min_val) const
{
  octave_idx_type nel = nnz ();

  if (nel == 0)
    return false;

  max_val = std::real (data (0));
  min_val = std::real (data (0));

  for (octave_idx_type i = 0; i < nel; i++)
    {
        Complex val = data (i);

        double r_val = std::real (val);
        double i_val = std::imag (val);

        if (r_val > max_val)
          max_val = r_val;

        if (i_val > max_val)
          max_val = i_val;

        if (r_val < min_val)
          min_val = r_val;

        if (i_val < min_val)
          min_val = i_val;

        if (D_NINT (r_val) != r_val || D_NINT (i_val) != i_val)
          return false;
    }

  return true;
}

bool
SparseComplexMatrix::too_large_for_float (void) const
{
  return test_any (xtoo_large_for_float);
}

// FIXME Do these really belong here?  Maybe they should be
// in a base class?

SparseBoolMatrix
SparseComplexMatrix::all (int dim) const
{
  SPARSE_ALL_OP (dim);
}

SparseBoolMatrix
SparseComplexMatrix::any (int dim) const
{
  SPARSE_ANY_OP (dim);
}

SparseComplexMatrix
SparseComplexMatrix::cumprod (int dim) const
{
  SPARSE_CUMPROD (SparseComplexMatrix, Complex, cumprod);
}

SparseComplexMatrix
SparseComplexMatrix::cumsum (int dim) const
{
  SPARSE_CUMSUM (SparseComplexMatrix, Complex, cumsum);
}

SparseComplexMatrix
SparseComplexMatrix::prod (int dim) const
{
  if ((rows () == 1 && dim == -1) || dim == 1)
    return transpose (). prod (0). transpose ();
  else
    {
      SPARSE_REDUCTION_OP (SparseComplexMatrix, Complex, *=,
                           (cidx (j+1) - cidx (j) < nr ? 0.0 : 1.0), 1.0);
    }
}

SparseComplexMatrix
SparseComplexMatrix::sum (int dim) const
{
  SPARSE_REDUCTION_OP (SparseComplexMatrix, Complex, +=, 0.0, 0.0);
}

SparseComplexMatrix
SparseComplexMatrix::sumsq (int dim) const
{
#define ROW_EXPR \
  Complex d = data (i); \
  tmp[ridx (i)] += d * conj (d)

#define COL_EXPR \
  Complex d = data (i); \
  tmp[j] += d * conj (d)

  SPARSE_BASE_REDUCTION_OP (SparseComplexMatrix, Complex, ROW_EXPR,
                            COL_EXPR, 0.0, 0.0);

#undef ROW_EXPR
#undef COL_EXPR
}

SparseMatrix SparseComplexMatrix::abs (void) const
{
  octave_idx_type nz = nnz ();
  octave_idx_type nc = cols ();

  SparseMatrix retval (rows (), nc, nz);

  for (octave_idx_type i = 0; i < nc + 1; i++)
    retval.cidx (i) = cidx (i);

  for (octave_idx_type i = 0; i < nz; i++)
    {
      retval.data (i) = std::abs (data (i));
      retval.ridx (i) = ridx (i);
    }

  return retval;
}

SparseComplexMatrix
SparseComplexMatrix::diag (octave_idx_type k) const
{
  return MSparse<Complex>::diag (k);
}

std::ostream&
operator << (std::ostream& os, const SparseComplexMatrix& a)
{
  octave_idx_type nc = a.cols ();

   // add one to the printed indices to go from
   //  zero-based to one-based arrays
   for (octave_idx_type j = 0; j < nc; j++)
     {
       octave_quit ();
       for (octave_idx_type i = a.cidx (j); i < a.cidx (j+1); i++)
         {
           os << a.ridx (i) + 1 << " "  << j + 1 << " ";
           octave_write_complex (os, a.data (i));
           os << "\n";
         }
     }

  return os;
}

std::istream&
operator >> (std::istream& is, SparseComplexMatrix& a)
{
  typedef SparseComplexMatrix::element_type elt_type;

  return read_sparse_matrix<elt_type> (is, a, octave_read_value<Complex>);
}

SparseComplexMatrix
operator * (const SparseComplexMatrix& m, const SparseMatrix& a)
{
  SPARSE_SPARSE_MUL (SparseComplexMatrix, Complex, double);
}

SparseComplexMatrix
operator * (const SparseMatrix& m, const SparseComplexMatrix& a)
{
  SPARSE_SPARSE_MUL (SparseComplexMatrix, Complex, Complex);
}

SparseComplexMatrix
operator * (const SparseComplexMatrix& m, const SparseComplexMatrix& a)
{
  SPARSE_SPARSE_MUL (SparseComplexMatrix, Complex, Complex);
}

ComplexMatrix
operator * (const ComplexMatrix& m, const SparseMatrix& a)
{
  FULL_SPARSE_MUL (ComplexMatrix, double, Complex (0.,0.));
}

ComplexMatrix
operator * (const Matrix& m, const SparseComplexMatrix& a)
{
  FULL_SPARSE_MUL (ComplexMatrix, Complex, Complex (0.,0.));
}

ComplexMatrix
operator * (const ComplexMatrix& m, const SparseComplexMatrix& a)
{
  FULL_SPARSE_MUL (ComplexMatrix, Complex, Complex (0.,0.));
}

ComplexMatrix
mul_trans (const ComplexMatrix& m, const SparseComplexMatrix& a)
{
  FULL_SPARSE_MUL_TRANS (ComplexMatrix, Complex, Complex (0.,0.), );
}

ComplexMatrix
mul_herm (const ComplexMatrix& m, const SparseComplexMatrix& a)
{
  FULL_SPARSE_MUL_TRANS (ComplexMatrix, Complex, Complex (0.,0.), conj);
}

ComplexMatrix
operator * (const SparseComplexMatrix& m, const Matrix& a)
{
  SPARSE_FULL_MUL (ComplexMatrix, double, Complex (0.,0.));
}

ComplexMatrix
operator * (const SparseMatrix& m, const ComplexMatrix& a)
{
  SPARSE_FULL_MUL (ComplexMatrix, Complex, Complex (0.,0.));
}

ComplexMatrix
operator * (const SparseComplexMatrix& m, const ComplexMatrix& a)
{
  SPARSE_FULL_MUL (ComplexMatrix, Complex, Complex (0.,0.));
}

ComplexMatrix
trans_mul (const SparseComplexMatrix& m, const ComplexMatrix& a)
{
  SPARSE_FULL_TRANS_MUL (ComplexMatrix, Complex, Complex (0.,0.), );
}

ComplexMatrix
herm_mul (const SparseComplexMatrix& m, const ComplexMatrix& a)
{
  SPARSE_FULL_TRANS_MUL (ComplexMatrix, Complex, Complex (0.,0.), conj);
}

// diag * sparse and sparse * diag
SparseComplexMatrix
operator * (const DiagMatrix& d, const SparseComplexMatrix& a)
{
  return do_mul_dm_sm<SparseComplexMatrix> (d, a);
}
SparseComplexMatrix
operator * (const SparseComplexMatrix& a, const DiagMatrix& d)
{
  return do_mul_sm_dm<SparseComplexMatrix> (a, d);
}

SparseComplexMatrix
operator * (const ComplexDiagMatrix& d, const SparseMatrix& a)
{
  return do_mul_dm_sm<SparseComplexMatrix> (d, a);
}
SparseComplexMatrix
operator * (const SparseMatrix& a, const ComplexDiagMatrix& d)
{
  return do_mul_sm_dm<SparseComplexMatrix> (a, d);
}

SparseComplexMatrix
operator * (const ComplexDiagMatrix& d, const SparseComplexMatrix& a)
{
  return do_mul_dm_sm<SparseComplexMatrix> (d, a);
}
SparseComplexMatrix
operator * (const SparseComplexMatrix& a, const ComplexDiagMatrix& d)
{
  return do_mul_sm_dm<SparseComplexMatrix> (a, d);
}

SparseComplexMatrix
operator + (const ComplexDiagMatrix& d, const SparseMatrix& a)
{
  return do_add_dm_sm<SparseComplexMatrix> (d, a);
}
SparseComplexMatrix
operator + (const DiagMatrix& d, const SparseComplexMatrix& a)
{
  return do_add_dm_sm<SparseComplexMatrix> (d, a);
}
SparseComplexMatrix
operator + (const ComplexDiagMatrix& d, const SparseComplexMatrix& a)
{
  return do_add_dm_sm<SparseComplexMatrix> (d, a);
}
SparseComplexMatrix
operator + (const SparseMatrix& a, const ComplexDiagMatrix& d)
{
  return do_add_sm_dm<SparseComplexMatrix> (a, d);
}
SparseComplexMatrix
operator + (const SparseComplexMatrix& a, const DiagMatrix& d)
{
  return do_add_sm_dm<SparseComplexMatrix> (a, d);
}
SparseComplexMatrix
operator + (const SparseComplexMatrix&a, const ComplexDiagMatrix& d)
{
  return do_add_sm_dm<SparseComplexMatrix> (a, d);
}

SparseComplexMatrix
operator - (const ComplexDiagMatrix& d, const SparseMatrix& a)
{
  return do_sub_dm_sm<SparseComplexMatrix> (d, a);
}
SparseComplexMatrix
operator - (const DiagMatrix& d, const SparseComplexMatrix& a)
{
  return do_sub_dm_sm<SparseComplexMatrix> (d, a);
}
SparseComplexMatrix
operator - (const ComplexDiagMatrix& d, const SparseComplexMatrix& a)
{
  return do_sub_dm_sm<SparseComplexMatrix> (d, a);
}
SparseComplexMatrix
operator - (const SparseMatrix& a, const ComplexDiagMatrix& d)
{
  return do_sub_sm_dm<SparseComplexMatrix> (a, d);
}
SparseComplexMatrix
operator - (const SparseComplexMatrix& a, const DiagMatrix& d)
{
  return do_sub_sm_dm<SparseComplexMatrix> (a, d);
}
SparseComplexMatrix
operator - (const SparseComplexMatrix&a, const ComplexDiagMatrix& d)
{
  return do_sub_sm_dm<SparseComplexMatrix> (a, d);
}

// perm * sparse and sparse * perm

SparseComplexMatrix
operator * (const PermMatrix& p, const SparseComplexMatrix& a)
{
  return octinternal_do_mul_pm_sm (p, a);
}

SparseComplexMatrix
operator * (const SparseComplexMatrix& a, const PermMatrix& p)
{
  return octinternal_do_mul_sm_pm (a, p);
}

// FIXME -- it would be nice to share code among the min/max
// functions below.

#define EMPTY_RETURN_CHECK(T) \
  if (nr == 0 || nc == 0) \
    return T (nr, nc);

SparseComplexMatrix
min (const Complex& c, const SparseComplexMatrix& m)
{
  SparseComplexMatrix result;

  octave_idx_type nr = m.rows ();
  octave_idx_type nc = m.columns ();

  EMPTY_RETURN_CHECK (SparseComplexMatrix);

  if (abs (c) == 0.)
    return SparseComplexMatrix (nr, nc);
  else
    {
      result = SparseComplexMatrix (m);

      for (octave_idx_type j = 0; j < nc; j++)
        for (octave_idx_type i = m.cidx (j); i < m.cidx (j+1); i++)
          result.data (i) = xmin (c, m.data (i));
    }

  return result;
}

SparseComplexMatrix
min (const SparseComplexMatrix& m, const Complex& c)
{
  return min (c, m);
}

SparseComplexMatrix
min (const SparseComplexMatrix& a, const SparseComplexMatrix& b)
{
  SparseComplexMatrix r;

  if ((a.rows () == b.rows ()) && (a.cols () == b.cols ()))
    {
      octave_idx_type a_nr = a.rows ();
      octave_idx_type a_nc = a.cols ();

      octave_idx_type b_nr = b.rows ();
      octave_idx_type b_nc = b.cols ();

      if (a_nr == 0 || b_nc == 0 || a.nnz () == 0 || b.nnz () == 0)
        return SparseComplexMatrix (a_nr, a_nc);

      if (a_nr != b_nr || a_nc != b_nc)
        gripe_nonconformant ("min", a_nr, a_nc, b_nr, b_nc);
      else
        {
          r = SparseComplexMatrix (a_nr, a_nc, (a.nnz () + b.nnz ()));

          octave_idx_type jx = 0;
          r.cidx (0) = 0;
          for (octave_idx_type i = 0 ; i < a_nc ; i++)
            {
              octave_idx_type  ja = a.cidx (i);
              octave_idx_type  ja_max = a.cidx (i+1);
              bool ja_lt_max= ja < ja_max;

              octave_idx_type  jb = b.cidx (i);
              octave_idx_type  jb_max = b.cidx (i+1);
              bool jb_lt_max = jb < jb_max;

              while (ja_lt_max || jb_lt_max )
                {
                  octave_quit ();
                  if ((! jb_lt_max) ||
                      (ja_lt_max && (a.ridx (ja) < b.ridx (jb))))
                    {
                      Complex tmp = xmin (a.data (ja), 0.);
                      if (tmp != 0.)
                        {
                          r.ridx (jx) = a.ridx (ja);
                          r.data (jx) = tmp;
                          jx++;
                        }
                      ja++;
                      ja_lt_max= ja < ja_max;
                    }
                  else if (( !ja_lt_max ) ||
                           (jb_lt_max && (b.ridx (jb) < a.ridx (ja)) ) )
                    {
                      Complex tmp = xmin (0., b.data (jb));
                      if (tmp != 0.)
                        {
                          r.ridx (jx) = b.ridx (jb);
                          r.data (jx) = tmp;
                          jx++;
                        }
                      jb++;
                      jb_lt_max= jb < jb_max;
                    }
                  else
                    {
                      Complex tmp = xmin (a.data (ja), b.data (jb));
                      if (tmp != 0.)
                        {
                          r.data (jx) = tmp;
                          r.ridx (jx) = a.ridx (ja);
                          jx++;
                        }
                      ja++;
                      ja_lt_max= ja < ja_max;
                      jb++;
                      jb_lt_max= jb < jb_max;
                    }
                }
              r.cidx (i+1) = jx;
            }

          r.maybe_compress ();
        }
    }
  else
    (*current_liboctave_error_handler) ("matrix size mismatch");

  return r;
}

SparseComplexMatrix
max (const Complex& c, const SparseComplexMatrix& m)
{
  SparseComplexMatrix result;

  octave_idx_type nr = m.rows ();
  octave_idx_type nc = m.columns ();

  EMPTY_RETURN_CHECK (SparseComplexMatrix);

  // Count the number of non-zero elements
  if (xmax (c, 0.) != 0.)
    {
      result = SparseComplexMatrix (nr, nc, c);
      for (octave_idx_type j = 0; j < nc; j++)
        for (octave_idx_type i = m.cidx (j); i < m.cidx (j+1); i++)
          result.xdata (m.ridx (i) + j * nr) = xmax (c, m.data (i));
    }
  else
    result = SparseComplexMatrix (m);

  return result;
}

SparseComplexMatrix
max (const SparseComplexMatrix& m, const Complex& c)
{
  return max (c, m);
}

SparseComplexMatrix
max (const SparseComplexMatrix& a, const SparseComplexMatrix& b)
{
  SparseComplexMatrix r;

  if ((a.rows () == b.rows ()) && (a.cols () == b.cols ()))
    {
      octave_idx_type a_nr = a.rows ();
      octave_idx_type a_nc = a.cols ();

      octave_idx_type b_nr = b.rows ();
      octave_idx_type b_nc = b.cols ();

      if (a_nr == 0 || b_nc == 0)
        return SparseComplexMatrix (a_nr, a_nc);
      if (a.nnz () == 0)
        return SparseComplexMatrix (b);
      if (b.nnz () == 0)
        return SparseComplexMatrix (a);

      if (a_nr != b_nr || a_nc != b_nc)
        gripe_nonconformant ("min", a_nr, a_nc, b_nr, b_nc);
      else
        {
          r = SparseComplexMatrix (a_nr, a_nc, (a.nnz () + b.nnz ()));

          octave_idx_type jx = 0;
          r.cidx (0) = 0;
          for (octave_idx_type i = 0 ; i < a_nc ; i++)
            {
              octave_idx_type  ja = a.cidx (i);
              octave_idx_type  ja_max = a.cidx (i+1);
              bool ja_lt_max= ja < ja_max;

              octave_idx_type  jb = b.cidx (i);
              octave_idx_type  jb_max = b.cidx (i+1);
              bool jb_lt_max = jb < jb_max;

              while (ja_lt_max || jb_lt_max )
                {
                  octave_quit ();
                  if ((! jb_lt_max) ||
                      (ja_lt_max && (a.ridx (ja) < b.ridx (jb))))
                    {
                      Complex tmp = xmax (a.data (ja), 0.);
                      if (tmp != 0.)
                        {
                          r.ridx (jx) = a.ridx (ja);
                          r.data (jx) = tmp;
                          jx++;
                        }
                      ja++;
                      ja_lt_max= ja < ja_max;
                    }
                  else if (( !ja_lt_max ) ||
                           (jb_lt_max && (b.ridx (jb) < a.ridx (ja)) ) )
                    {
                      Complex tmp = xmax (0., b.data (jb));
                      if (tmp != 0.)
                        {
                          r.ridx (jx) = b.ridx (jb);
                          r.data (jx) = tmp;
                          jx++;
                        }
                      jb++;
                      jb_lt_max= jb < jb_max;
                    }
                  else
                    {
                      Complex tmp = xmax (a.data (ja), b.data (jb));
                      if (tmp != 0.)
                        {
                          r.data (jx) = tmp;
                          r.ridx (jx) = a.ridx (ja);
                          jx++;
                        }
                      ja++;
                      ja_lt_max= ja < ja_max;
                      jb++;
                      jb_lt_max= jb < jb_max;
                    }
                }
              r.cidx (i+1) = jx;
            }

          r.maybe_compress ();
        }
    }
  else
    (*current_liboctave_error_handler) ("matrix size mismatch");

  return r;
}

SPARSE_SMS_CMP_OPS (SparseComplexMatrix, 0.0, real, Complex,
                   0.0, real)
SPARSE_SMS_BOOL_OPS (SparseComplexMatrix, Complex, 0.0)

SPARSE_SSM_CMP_OPS (Complex, 0.0, real, SparseComplexMatrix,
                   0.0, real)
SPARSE_SSM_BOOL_OPS (Complex, SparseComplexMatrix, 0.0)

SPARSE_SMSM_CMP_OPS (SparseComplexMatrix, 0.0, real, SparseComplexMatrix,
                     0.0, real)
SPARSE_SMSM_BOOL_OPS (SparseComplexMatrix, SparseComplexMatrix, 0.0)