--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/liboctave/Sparse.cc	Fri Feb 25 19:55:28 2005 +0000
@@ -0,0 +1,2834 @@
+// Template sparse array class
+/*
+
+Copyright (C) 2004 David Bateman
+Copyright (C) 1998-2004 Andy Adler
+
+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 2, 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 this program; see the file COPYING.  If not, write to the Free
+Software Foundation, 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+
+*/
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <cassert>
+#include <climits>
+
+#include <iostream>
+#include <vector>
+
+#include "Array.h"
+#include "Array-flags.h"
+#include "Array-util.h"
+#include "Range.h"
+#include "idx-vector.h"
+#include "lo-error.h"
+#include "lo-sstream.h"
+#include "quit.h"
+
+#include "Sparse.h"
+#include "sparse-sort.h"
+#include "oct-spparms.h"
+
+template <class T>
+T&
+Sparse<T>::SparseRep::elem (int _r, int _c)
+{
+  int i;
+
+  if (nnz > 0)
+    {
+      for (i = c[_c]; i < c[_c + 1]; i++)
+	if (r[i] == _r)
+	  return d[i];
+	else if (r[i] > _r)
+	  break;
+
+      // Ok, If we've gotten here, we're in trouble.. Have to create a 
+      // new element in the sparse array. This' gonna be slow!!!
+      if (c[ncols+1] == nnz)
+	{
+	  (*current_liboctave_error_handler)
+	    ("Sparse::SparseRep::elem (int, int): sparse matrix filled");
+	  return *d;
+	}
+
+      int to_move = c[ncols] - i;
+      if (to_move != 0)
+	{
+	  for (int j = c[ncols]; j > i; j--)
+	    {
+	      d[j] = d[j-1];
+	      r[j] = r[j-1];
+	    }
+	}
+
+      for (int j = _c + 1; j < ncols + 1; j++)
+	c[j] = c[j] + 1;
+      
+      d[i] = 0.;
+      r[i] = _r;
+
+      return d[i];
+    }
+  else
+    {
+      (*current_liboctave_error_handler)
+	("Sparse::SparseRep::elem (int, int): sparse matrix filled");
+      return *d;
+    }
+}
+
+template <class T>
+T
+Sparse<T>::SparseRep::celem (int _r, int _c) const
+{
+  if (nnz > 0)
+    for (int i = c[_c]; i < c[_c + 1]; i++)
+      if (r[i] == _r)
+	return d[i];
+  return T ();
+}
+
+template <class T>
+void
+Sparse<T>::SparseRep::maybe_compress (bool remove_zeros)
+{
+  int ndel = nnz - c[ncols];
+  int nzero = 0;
+
+  if (remove_zeros)
+    for (int i = 0; i < nnz - ndel; i++)
+      if (d[i] == T ())
+	nzero++;
+
+  if (!ndel && !nzero)
+    return;
+
+  if (!nzero)
+    {
+      int new_nnz = nnz - ndel;
+
+      T *new_data = new T [new_nnz];
+      for (int i = 0; i < new_nnz; i++)
+	new_data[i] = d[i];
+      delete [] d;
+      d = new_data;
+
+      int *new_ridx = new int [new_nnz];
+      for (int i = 0; i < new_nnz; i++)
+	new_ridx[i] = r[i];
+      delete [] r;
+      r = new_ridx;
+    }
+  else
+    {
+      int new_nnz = nnz - ndel - nzero;
+
+      T *new_data = new T [new_nnz];
+      int *new_ridx = new int [new_nnz];
+
+      int ii = 0;
+      int ic = 0;
+      for (int j = 0; j < ncols; j++)
+	{
+	  for (int k = ic; k < c[j+1]; k++)
+	    if (d[k] != T ())
+	      {
+		new_data [ii] = d[k];
+		new_ridx [ii++] = r[k];
+	      }
+	  ic = c[j+1];
+	  c[j+1] = ii;
+	}
+
+      delete [] d;
+      d = new_data;
+
+      delete [] r;
+      r = new_ridx;
+    }
+
+  nnz -= ndel + nzero;
+}
+
+template <class T>
+void
+Sparse<T>::SparseRep::change_length (int nz)
+{
+  if (nz != nnz)
+    {
+      int min_nnz = (nz < nnz ? nz : nnz);
+
+      int * new_ridx = new int [nz];
+      for (int i = 0; i < min_nnz; i++)
+	new_ridx[i] = r[i];
+
+      delete [] r;
+      r = new_ridx;
+
+      T * new_data = new T [nz];
+      for (int i = 0; i < min_nnz; i++)
+	new_data[i] = d[i];
+
+      delete [] d;
+      d = new_data;
+
+      if (nz < nnz)
+	for (int i = 0; i <= ncols; i++)
+	  if (c[i] > nz)
+	    c[i] = nz;
+
+      nnz = nz;
+    }
+}
+
+template <class T>
+template <class U>
+Sparse<T>::Sparse (const Sparse<U>& a)
+  : dimensions (a.dimensions), idx (0), idx_count (0)
+{
+  if (a.nnz () == 0)
+    rep = new typename Sparse<T>::SparseRep (rows (), cols());
+  else
+    {
+      rep = new typename Sparse<T>::SparseRep (rows (), cols (), a.nnz ());
+      
+      int nz = nnz ();
+      int nc = cols ();
+      for (int i = 0; i < nz; i++)
+	{
+	  xdata (i) = T (a.data (i));
+	  xridx (i) = a.ridx (i);
+	}
+      for (int i = 0; i < nc + 1; i++)
+	xcidx (i) = a.cidx (i);
+    }
+}
+
+template <class T>
+Sparse<T>::Sparse (int nr, int nc, T val)
+  : rep (new typename Sparse<T>::SparseRep (nr, nc, nr*nc)),
+    dimensions (dim_vector (nr, nc)), idx (0), idx_count (0)
+{ 
+
+  int ii = 0;
+  xcidx (0) = 0;
+  for (int j = 0; j < nc; j++)
+    {
+      for (int i = 0; i < nr; i++)
+	{
+	  xdata (ii) = val;
+	  xridx (ii++) = i;
+	} 
+      xcidx (j+1) = ii;
+    }
+}
+
+template <class T>
+Sparse<T>::Sparse (const dim_vector& dv)
+  : dimensions (dv), idx (0), idx_count (0)
+{ 
+  if (dv.length() != 2)
+    (*current_liboctave_error_handler)
+      ("Sparse::Sparse (const dim_vector&): dimension mismatch");
+  else
+    rep = new typename Sparse<T>::SparseRep (dv(0), dv(1));
+}
+
+template <class T>
+Sparse<T>::Sparse (const Sparse<T>& a, const dim_vector& dv)
+  : dimensions (dv), idx (0), idx_count (0)
+{
+
+  // Work in unsigned long long to avoid overflow issues with numel
+  unsigned long long a_nel = static_cast<unsigned long long>(a.rows ()) *
+    static_cast<unsigned long long>(a.cols ());
+  unsigned long long dv_nel = static_cast<unsigned long long>(dv (0)) *
+    static_cast<unsigned long long>(dv (1));
+
+  if (a_nel != dv_nel)
+    (*current_liboctave_error_handler)
+      ("Sparse::Sparse (const Sparse&, const dim_vector&): dimension mismatch");
+  else
+    {
+      dim_vector old_dims = a.dims();
+      int new_nnz = a.nnz ();
+      int new_nr = dv (0);
+      int new_nc = dv (1);
+      int old_nr = old_dims (0);
+      int old_nc = old_dims (1);
+
+      rep = new typename Sparse<T>::SparseRep (new_nr, new_nc, new_nnz);
+
+      int kk = 0;
+      xcidx(0) = 0;
+      for (int i = 0; i < old_nc; i++)
+	for (int j = a.cidx(i); j < a.cidx(i+1); j++)
+	  {
+	    int tmp = i * old_nr + a.ridx(j);
+	    int ii = tmp % new_nr;
+	    int jj = (tmp - ii) / new_nr; 
+	    for (int k = kk; k < jj; k++)
+	      xcidx(k+1) = j;
+	    kk = jj;
+	    xdata(j) = a.data(j);
+	    xridx(j) = ii;
+	  }
+      for (int k = kk; k < new_nc; k++)
+	xcidx(k+1) = new_nnz;
+    }
+}
+
+template <class T>
+Sparse<T>::Sparse (const Array<T>& a, const Array<int>& r, 
+		   const Array<int>& c, int nr,
+		   int nc, bool sum_terms)
+  : dimensions (dim_vector (nr, nc)), idx (0), idx_count (0)
+{
+  int a_len = a.length ();
+  int r_len = r.length ();
+  int c_len = c.length ();
+  bool ri_scalar = (r_len == 1); 
+  bool ci_scalar = (c_len == 1);
+  bool cf_scalar = (a_len == 1);
+  
+  if ((a_len != r_len && !cf_scalar && !ri_scalar) ||
+      (a_len != c_len && !cf_scalar && !ci_scalar) ||
+      (r_len != c_len && !ri_scalar && !ci_scalar) || nr < 0 || nc < 0)
+    {
+      (*current_liboctave_error_handler)
+	("Sparse::Sparse (const Array<T>&, const Array<int>&, ...): dimension mismatch");
+      rep = nil_rep ();
+      dimensions = dim_vector (0, 0);
+    }
+  else
+    {
+      int max_nnz = (r_len > c_len ? r_len : c_len);
+
+      OCTAVE_LOCAL_BUFFER (octave_sparse_sort_idxl *, sidx, max_nnz);
+      OCTAVE_LOCAL_BUFFER (octave_sparse_sort_idxl, sidxX, max_nnz);
+
+      for (int i = 0; i < max_nnz; i++)
+	sidx[i] = &sidxX[i];
+
+      int actual_nnz = 0;
+      OCTAVE_QUIT;
+      for (int i = 0; i < max_nnz; i++) 
+	{
+	  int rowidx =  (ri_scalar ? r(0) : r(i));
+	  int colidx = (ci_scalar ? c(0) : c(i));
+	  if (rowidx < nr && rowidx >= 0 &&
+	      colidx < nc && colidx >= 0 ) 
+	    {
+	      if ( a (cf_scalar ? 0 : i ) != T ()) 
+		{
+		  sidx[actual_nnz]->r = rowidx;
+		  sidx[actual_nnz]->c = colidx;
+		  sidx[actual_nnz]->idx = i;
+		  actual_nnz++;	
+		}
+	    }
+	  else 
+	    {
+	      (*current_liboctave_error_handler)
+		("Sparse::Sparse : index (%d,%d) out of range", 
+		 rowidx + 1, colidx + 1);
+	      rep = nil_rep ();
+	      dimensions = dim_vector (0, 0);
+	      return;
+	    }
+	}
+  
+      if (actual_nnz == 0)
+	rep = new typename Sparse<T>::SparseRep (nr, nc);
+      else
+	{
+	  OCTAVE_QUIT;
+	  octave_sort<octave_sparse_sort_idxl *> 
+	    sort (octave_sparse_sidxl_comp);
+
+	  sort.sort (sidx, actual_nnz);
+	  OCTAVE_QUIT;
+
+	  // Now count the unique non-zero values
+	  int real_nnz = 1;
+	  for (int i = 1; i < actual_nnz; i++) 
+	    if (sidx[i-1]->r != sidx[i]->r || sidx[i-1]->c != sidx[i]->c) 
+	      real_nnz++;
+
+	  rep = new typename Sparse<T>::SparseRep (nr, nc, real_nnz);
+
+	  int cx = 0;
+	  int prev_rval = -1;
+	  int prev_cval = -1;
+	  int ii = -1;
+	  xcidx (0) = 0;
+	  for (int i = 0; i < actual_nnz; i++) 
+	    {
+	      OCTAVE_QUIT;
+	      int iidx = sidx[i]->idx;
+	      int rval = sidx[i]->r;
+	      int cval = sidx[i]->c;
+
+	      if (prev_cval < cval || (prev_rval < rval && prev_cval == cval)) 
+		{
+		  int ci = static_cast<int> (c (ci_scalar ? 0 : iidx));
+		  ii++;
+		  while (cx < ci) 
+		    xcidx (++cx) = ii;
+		  xdata(ii) = a (cf_scalar ? 0 : iidx);
+		  xridx(ii) = static_cast<int> (r (ri_scalar ? 0 : iidx));
+		} 
+	      else 
+		{
+		  if (sum_terms)
+		    xdata(ii) += a (cf_scalar ? 0 : iidx);
+		  else
+		    xdata(ii) =  a (cf_scalar ? 0 : iidx);
+		}
+	      prev_rval = rval;
+	      prev_cval = cval;
+	    } 
+
+	  while (cx < nc) 
+	    xcidx (++cx) = ii + 1;
+	}
+    }
+}
+
+template <class T>
+Sparse<T>::Sparse (const Array<T>& a, const Array<double>& r, 
+		   const Array<double>& c, int nr,
+		   int nc, bool sum_terms)
+  : dimensions (dim_vector (nr, nc)), idx (0), idx_count (0)
+{
+  int a_len = a.length ();
+  int r_len = r.length ();
+  int c_len = c.length ();
+  bool ri_scalar = (r_len == 1); 
+  bool ci_scalar = (c_len == 1);
+  bool cf_scalar = (a_len == 1);
+
+  if ((a_len != r_len && !cf_scalar && !ri_scalar) ||
+      (a_len != c_len && !cf_scalar && !ci_scalar) ||
+      (r_len != c_len && !ri_scalar && !ci_scalar) || nr < 0 || nc < 0)
+    {
+      (*current_liboctave_error_handler)
+	("Sparse::Sparse (const Array<T>&, const Array<double>&, ...): dimension mismatch");
+      rep = nil_rep ();
+      dimensions = dim_vector (0, 0);
+    }
+  else
+    {
+      int max_nnz = (r_len > c_len ? r_len : c_len);
+  
+      OCTAVE_LOCAL_BUFFER (octave_sparse_sort_idxl *, sidx, max_nnz);
+      OCTAVE_LOCAL_BUFFER (octave_sparse_sort_idxl, sidxX, max_nnz);
+
+      for (int i = 0; i < max_nnz; i++)
+	sidx[i] = &sidxX[i];
+
+      int actual_nnz = 0;
+      OCTAVE_QUIT;
+
+      for (int i = 0; i < max_nnz; i++) 
+	{
+	  int rowidx = static_cast<int> (ri_scalar ? r(0) : r(i));
+	  int colidx = static_cast<int> (ci_scalar ? c(0) : c(i));
+	  if (rowidx < nr && rowidx >= 0 &&
+	      colidx < nc && colidx >= 0 ) 
+	    {
+	      if ( a (cf_scalar ? 0 : i ) != T ()) 
+		{
+		  sidx[actual_nnz]->r = rowidx;
+		  sidx[actual_nnz]->c = colidx;
+		  sidx[actual_nnz]->idx = i;
+		  actual_nnz++;	
+		}
+	    }
+	  else 
+	    {
+	      (*current_liboctave_error_handler)
+		("Sparse::Sparse : index (%d,%d) out of range", 
+		 rowidx + 1, colidx + 1);
+	      rep = nil_rep ();
+	      dimensions = dim_vector (0, 0);
+	      return;
+	    }
+	}
+
+      if (actual_nnz == 0)
+	rep = new typename Sparse<T>::SparseRep (nr, nc);
+      else
+	{
+	  OCTAVE_QUIT;
+	  octave_sort<octave_sparse_sort_idxl *> 
+	    sort (octave_sparse_sidxl_comp);
+
+	  sort.sort (sidx, actual_nnz);
+	  OCTAVE_QUIT;
+
+	  // Now count the unique non-zero values
+	  int real_nnz = 1;
+	  for (int i = 1; i < actual_nnz; i++) 
+	    if (sidx[i-1]->r != sidx[i]->r || sidx[i-1]->c != sidx[i]->c) 
+	      real_nnz++;
+
+	  rep = new typename Sparse<T>::SparseRep (nr, nc, real_nnz);
+
+	  int cx = 0;
+	  int prev_rval = -1;
+	  int prev_cval = -1;
+	  int ii = -1;
+	  xcidx (0) = 0;
+	  for (int i = 0; i < actual_nnz; i++) 
+	    {
+	      OCTAVE_QUIT;
+	      int iidx = sidx[i]->idx;
+	      int rval = sidx[i]->r;
+	      int cval = sidx[i]->c;
+
+	      if (prev_cval < cval || (prev_rval < rval && prev_cval == cval)) 
+		{
+		  int ci = static_cast<int> (c (ci_scalar ? 0 : iidx));
+		  ii++;
+
+		  while (cx < ci) 
+		    xcidx (++cx) = ii;
+		  xdata(ii) = a (cf_scalar ? 0 : iidx);
+		  xridx(ii) = static_cast<int> (r (ri_scalar ? 0 : iidx));
+		} 
+	      else 
+		{
+		  if (sum_terms)
+		    xdata(ii) += a (cf_scalar ? 0 : iidx);
+		  else
+		    xdata(ii) =  a (cf_scalar ? 0 : iidx);
+		}
+	      prev_rval = rval;
+	      prev_cval = cval;
+	    } 
+
+	  while (cx < nc) 
+	    xcidx (++cx) = ii + 1;
+	}
+    }
+}
+
+template <class T>
+Sparse<T>::Sparse (const Array2<T>& a)
+  : dimensions (a.dims ()), idx (0), idx_count (0)
+{
+  int nr = rows ();
+  int nc = cols ();
+  int len = a.length ();
+  int new_nnz = 0;
+
+  // First count the number of non-zero terms
+  for (int i = 0; i < len; i++)
+    if (a(i) != T ())
+      new_nnz++;
+
+  rep = new typename Sparse<T>::SparseRep (nr, nc, new_nnz);
+
+  int ii = 0;
+  xcidx(0) = 0;
+  for (int j = 0; j < nc; j++)
+    {
+      for (int i = 0; i < nr; i++)
+	if (a.elem (i,j) != T ())
+	  {
+	    xdata(ii) = a.elem (i,j);
+	    xridx(ii++) = i;
+	  }
+      xcidx(j+1) = ii;
+    }
+}
+
+template <class T>
+Sparse<T>::Sparse (const Array<T>& a)
+  : dimensions (a.dims ()), idx (0), idx_count (0)
+{
+  if (dimensions.length () > 2)
+    (*current_liboctave_error_handler)
+      ("Sparse::Sparse (const Array<T>&): dimension mismatch");
+  else
+    {
+      int nr = rows ();
+      int nc = cols ();
+      int len = a.length ();
+      int new_nnz = 0;
+
+      // First count the number of non-zero terms
+      for (int i = 0; i < len; i++)
+	if (a(i) != T ())
+	  new_nnz++;
+
+      rep = new typename Sparse<T>::SparseRep (nr, nc, new_nnz);
+
+      int ii = 0;
+      xcidx(0) = 0;
+      for (int j = 0; j < nc; j++)
+	{
+	  for (int i = 0; i < nr; i++)
+	    if (a.elem (i,j) != T ())
+	      {
+		xdata(ii) = a.elem (i,j);
+		xridx(ii++) = i;
+	      }
+	  xcidx(j+1) = ii;
+	}
+    }
+}
+
+template <class T>
+Sparse<T>::~Sparse (void)
+{
+  if (--rep->count <= 0)
+    delete rep;
+
+  delete [] idx;
+}
+
+template <class T>
+int
+Sparse<T>::compute_index (const Array<int>& ra_idx) const
+{
+  int retval = -1;
+
+  int n = dimensions.length ();
+
+  if (n > 0 && n == ra_idx.length ())
+    {
+      retval = ra_idx(--n);
+
+      while (--n >= 0)
+	{
+	  retval *= dimensions(n);
+	  retval += ra_idx(n);
+	}
+    }
+  else
+    (*current_liboctave_error_handler)
+      ("Sparse<T>::compute_index: invalid ra_idxing operation");
+
+  return retval;
+}
+
+template <class T>
+T
+Sparse<T>::range_error (const char *fcn, int n) const
+{
+  (*current_liboctave_error_handler) ("%s (%d): range error", fcn, n);
+  return T ();
+}
+
+template <class T>
+T&
+Sparse<T>::range_error (const char *fcn, int n)
+{
+  (*current_liboctave_error_handler) ("%s (%d): range error", fcn, n);
+  static T foo;
+  return foo;
+}
+
+template <class T>
+T
+Sparse<T>::range_error (const char *fcn, int i, int j) const
+{
+  (*current_liboctave_error_handler)
+    ("%s (%d, %d): range error", fcn, i, j);
+  return T ();
+}
+
+template <class T>
+T&
+Sparse<T>::range_error (const char *fcn, int i, int j)
+{
+  (*current_liboctave_error_handler)
+    ("%s (%d, %d): range error", fcn, i, j);
+  static T foo;
+  return foo;
+}
+
+template <class T>
+T
+Sparse<T>::range_error (const char *fcn, const Array<int>& ra_idx) const
+{
+  OSSTREAM buf;
+
+  buf << fcn << " (";
+
+  int n = ra_idx.length ();
+
+  if (n > 0)
+    buf << ra_idx(0);
+
+  for (int i = 1; i < n; i++)
+    buf << ", " << ra_idx(i);
+
+  buf << "): range error";
+
+  buf << OSSTREAM_ENDS;
+
+  (*current_liboctave_error_handler) (OSSTREAM_C_STR (buf));
+
+  OSSTREAM_FREEZE (buf);
+
+  return T ();
+}
+
+template <class T>
+T&
+Sparse<T>::range_error (const char *fcn, const Array<int>& ra_idx)
+{
+  OSSTREAM buf;
+
+  buf << fcn << " (";
+
+  int n = ra_idx.length ();
+
+  if (n > 0)
+    buf << ra_idx(0);
+
+  for (int i = 1; i < n; i++)
+    buf << ", " << ra_idx(i);
+
+  buf << "): range error";
+
+  buf << OSSTREAM_ENDS;
+
+  (*current_liboctave_error_handler) (OSSTREAM_C_STR (buf));
+
+  OSSTREAM_FREEZE (buf);
+
+  static T foo;
+  return foo;
+}
+
+template <class T>
+Sparse<T>
+Sparse<T>::reshape (const dim_vector& new_dims) const
+{
+  Sparse<T> retval;
+
+  if (dimensions != new_dims)
+    {
+      if (dimensions.numel () == new_dims.numel ())
+	{
+	  int new_nnz = nnz ();
+	  int new_nr = new_dims (0);
+	  int new_nc = new_dims (1);
+	  int old_nr = rows ();
+	  int old_nc = cols ();
+	  retval = Sparse<T> (new_nr, new_nc, new_nnz);
+
+	  int kk = 0;
+	  retval.xcidx(0) = 0;
+	  for (int i = 0; i < old_nc; i++)
+	    for (int j = cidx(i); j < cidx(i+1); j++)
+	      {
+		int tmp = i * old_nr + ridx(j);
+		int ii = tmp % new_nr;
+		int jj = (tmp - ii) / new_nr; 
+		for (int k = kk; k < jj; k++)
+		  retval.xcidx(k+1) = j;
+		kk = jj;
+		retval.xdata(j) = data(j);
+		retval.xridx(j) = ii;
+	      }
+	  retval.xcidx(new_nc) = new_nnz;
+	}
+      else
+	(*current_liboctave_error_handler) ("reshape: size mismatch");
+    }
+  else
+    retval = *this;
+
+  return retval;
+}
+
+template <class T>
+Sparse<T>
+Sparse<T>::permute (const Array<int>& perm_vec, bool) const
+{
+  dim_vector dv = dims ();
+  dim_vector dv_new;
+
+  int nd = dv.length ();
+
+  dv_new.resize (nd);
+
+  // Need this array to check for identical elements in permutation array.
+  Array<bool> checked (nd, false);
+
+  // Find dimension vector of permuted array.
+  for (int i = 0; i < nd; i++)
+    {
+      int perm_el = perm_vec.elem (i);
+
+      if (perm_el > dv.length () || perm_el < 1)
+	{
+	  (*current_liboctave_error_handler)
+	    ("permutation vector contains an invalid element");
+
+	  return Sparse<T> ();
+	}
+
+      if (checked.elem(perm_el - 1))
+	{
+	  (*current_liboctave_error_handler)
+	    ("PERM cannot contain identical elements");
+
+	  return Sparse<T> ();
+	}
+      else
+	checked.elem(perm_el - 1) = true;
+
+      dv_new (i) = dv (perm_el - 1);
+    }
+
+  if (dv_new == dv)
+    return *this;
+  else
+    return transpose ();
+}
+
+template <class T>
+void
+Sparse<T>::resize_no_fill (const dim_vector& dv)
+{
+  int n = dv.length ();
+
+  if (n != 2)
+    {
+      (*current_liboctave_error_handler) ("sparse array must be 2-D");
+      return;
+    }
+
+  resize_no_fill (dv(0), dv(1));
+}
+
+template <class T>
+void
+Sparse<T>::resize_no_fill (int r, int c)
+{
+  if (r < 0 || c < 0)
+    {
+      (*current_liboctave_error_handler)
+	("can't resize to negative dimension");
+      return;
+    }
+
+  if (ndims () == 0)
+    dimensions = dim_vector (0, 0);
+
+  if (r == dim1 () && c == dim2 ())
+    return;
+
+  typename Sparse<T>::SparseRep *old_rep = Sparse<T>::rep;
+  int nc = cols ();
+  int nr = rows ();
+
+  if (nnz () == 0 || r == 0 || c == 0)
+    // Special case of redimensioning to/from a sparse matrix with 
+    // no elements
+    rep = new typename Sparse<T>::SparseRep (r, c);
+  else
+    {
+      int n = 0;
+      Sparse<T> tmpval;
+      if (r >= nr)
+	{
+	  if (c > nc)
+	    n = cidx(nc);
+	  else
+	    n = cidx(c);
+
+	  tmpval = Sparse<T> (r, c, n);
+
+	  if (c > nc)
+	    {
+	      for (int i = 0; i < nc; i++)
+		tmpval.cidx(i) = cidx(i);
+	      for (int i = nc+2; i < c; i++)
+		tmpval.cidx(i) = tmpval.cidx(i-1);
+	    }
+	  else if (c <= nc)
+	    for (int i = 0; i < c; i++)
+	      tmpval.cidx(i) = cidx(i);
+	  
+	  for (int i = 0; i < n; i++)
+	    {
+	      tmpval.data(i) = data(i);
+	      tmpval.ridx(i) = ridx(i);
+	    }
+	}
+      else
+	{
+	  // Count how many non zero terms before we do anything
+	  for (int i = 0; i < c; i++)
+	    for (int j = cidx(i); j < cidx(i+1); j++)
+	      if (ridx(j) < r)
+		n++;
+
+	  if (n)
+	    {
+	      // Now that we know the size we can do something
+	      tmpval = Sparse<T> (r, c, n);
+
+	      tmpval.cidx(0);
+	      for (int i = 0, ii = 0; i < c; i++)
+		{
+		  for (int j = cidx(i); j < cidx(i+1); j++)
+		    if (ridx(j) < r)
+		      {
+			tmpval.data(ii) = data(j);
+			tmpval.ridx(ii++) = ridx(j);
+		      }
+		  tmpval.cidx(i+1) = ii;
+		}
+	    }
+	  else
+	    tmpval = Sparse<T> (r, c);
+	}
+
+      rep = tmpval.rep;
+      rep->count++;
+    }
+
+  dimensions = dim_vector (r, c);
+
+  if (--old_rep->count <= 0)
+    delete old_rep;
+}
+
+template <class T>
+Sparse<T>&
+Sparse<T>::insert (const Sparse<T>& a, int r, int c)
+{
+  int a_rows = a.rows ();
+  int a_cols = a.cols ();
+  int nr = rows ();
+  int nc = cols ();
+
+  if (r < 0 || r + a_rows > rows () || c < 0 || c + a_cols > cols ())
+    {
+      (*current_liboctave_error_handler) ("range error for insert");
+      return *this;
+    }
+
+  // First count the number of elements in the final array
+  int nel = cidx(c) + a.nnz ();
+
+  if (c + a_cols < nc)
+    nel += cidx(nc) - cidx(c + a_cols);
+
+  for (int i = c; i < c + a_cols; i++)
+    for (int j = cidx(i); j < cidx(i+1); j++)
+      if (ridx(j) < r || ridx(j) >= r + a_rows)
+	nel++;
+
+  Sparse<T> tmp (*this);
+  --rep->count;
+  rep = new typename Sparse<T>::SparseRep (nr, nc, nel);
+
+  for (int i = 0; i < tmp.cidx(c); i++)
+    {
+      data(i) = tmp.data(i);
+      ridx(i) = tmp.ridx(i);
+    }
+  for (int i = 0; i < c + 1; i++)
+    cidx(i) = tmp.cidx(i);
+
+  int ii = cidx(c);
+
+  for (int i = c; i < c + a_cols; i++)
+    {
+      OCTAVE_QUIT;
+
+      for (int j = tmp.cidx(i); j < tmp.cidx(i+1); j++)
+	if (tmp.ridx(j) < r)
+	  {
+	    data(ii) = tmp.data(j);
+	    ridx(ii++) = tmp.ridx(j);
+	  }
+
+      OCTAVE_QUIT;
+
+      for (int j = a.cidx(i-c); j < a.cidx(i-c+1); j++)
+	{
+	  data(ii) = a.data(j);
+	  ridx(ii++) = r + a.ridx(j);
+	}
+
+      OCTAVE_QUIT;
+
+      for (int j = tmp.cidx(i); j < tmp.cidx(i+1); j++)
+	if (tmp.ridx(j) >= r + a_rows)
+	  {
+	    data(ii) = tmp.data(j);
+	    ridx(ii++) = tmp.ridx(j);
+	  }
+
+      cidx(i+1) = ii;
+    }
+
+  for (int i = c + a_cols; i < nc; i++)
+    {
+      for (int j = tmp.cidx(i); j < tmp.cidx(i+1); j++)
+	{
+	  data(ii) = tmp.data(j);
+	  ridx(ii++) = tmp.ridx(j);
+	}
+      cidx(i+1) = ii;
+    }
+
+  return *this;
+}
+
+template <class T>
+Sparse<T>&
+Sparse<T>::insert (const Sparse<T>& a, const Array<int>& ra_idx)
+{
+
+  if (ra_idx.length () != 2)
+    {
+      (*current_liboctave_error_handler) ("range error for insert");
+      return *this;
+    }
+
+  return insert (a, ra_idx (0), ra_idx (1));
+}
+
+template <class T>
+Sparse<T>
+Sparse<T>::transpose (void) const
+{
+  assert (ndims () == 2);
+
+  int nr = rows ();
+  int nc = cols ();
+  int nz = nnz ();
+  Sparse<T> retval (nc, nr, nz);
+
+  retval.cidx(0) = 0;
+  for (int i = 0, iidx = 0; i < nr; i++)
+    {
+      for (int j = 0; j < nc; j++)
+	for (int k = cidx(j); k < cidx(j+1); k++)
+	  if (ridx(k) == i)
+	    {
+	      retval.data(iidx) = data(k);
+	      retval.ridx(iidx++) = j;
+	    }
+      retval.cidx(i+1) = iidx;
+    }
+
+  return retval;
+}
+
+template <class T>
+void
+Sparse<T>::clear_index (void)
+{
+  delete [] idx;
+  idx = 0;
+  idx_count = 0;
+}
+
+template <class T>
+void
+Sparse<T>::set_index (const idx_vector& idx_arg)
+{
+  int nd = ndims ();
+
+  if (! idx && nd > 0)
+    idx = new idx_vector [nd];
+
+  if (idx_count < nd)
+    {
+      idx[idx_count++] = idx_arg;
+    }
+  else
+    {
+      idx_vector *new_idx = new idx_vector [idx_count+1];
+
+      for (int i = 0; i < idx_count; i++)
+	new_idx[i] = idx[i];
+
+      new_idx[idx_count++] = idx_arg;
+
+      delete [] idx;
+
+      idx = new_idx;
+    }
+}
+
+template <class T>
+void
+Sparse<T>::maybe_delete_elements (idx_vector& idx_arg)
+{
+  int nr = dim1 ();
+  int nc = dim2 ();
+
+  if (nr == 0 && nc == 0)
+    return;
+
+  int n;
+  if (nr == 1)
+    n = nc;
+  else if (nc == 1)
+    n = nr;
+  else
+    {
+      // Reshape to row vector for Matlab compatibility.
+
+      n = nr * nc;
+      nr = 1;
+      nc = n;
+    }
+
+  if (idx_arg.is_colon_equiv (n, 1))
+    {
+      // Either A(:) = [] or A(idx) = [] with idx enumerating all
+      // elements, so we delete all elements and return [](0x0).  To
+      // preserve the orientation of the vector, you have to use
+      // A(idx,:) = [] (delete rows) or A(:,idx) (delete columns).
+
+      resize_no_fill (0, 0);
+      return;
+    }
+
+  idx_arg.sort (true);
+
+  int num_to_delete = idx_arg.length (n);
+
+  if (num_to_delete != 0)
+    {
+      int new_n = n;
+      int new_nnz = nnz ();
+
+      int iidx = 0;
+
+      const Sparse<T> tmp (*this);
+
+      for (int i = 0; i < n; i++)
+	{
+	  OCTAVE_QUIT;
+
+	  if (i == idx_arg.elem (iidx))
+	    {
+	      iidx++;
+	      new_n--;
+
+	      if (tmp.elem (i) != T ())
+		new_nnz--;
+
+	      if (iidx == num_to_delete)
+		break;
+	    }
+	}
+
+      if (new_n > 0)
+	{
+	  rep->count--;
+
+	  if (nr == 1)
+	    rep = new typename Sparse<T>::SparseRep (1, new_n, new_nnz);
+	  else
+	    rep = new typename Sparse<T>::SparseRep (new_n, 1, new_nnz);
+
+	  int ii = 0;
+	  int jj = 0;
+	  iidx = 0;
+	  for (int i = 0; i < n; i++)
+	    {
+	      OCTAVE_QUIT;
+
+	      if (iidx < num_to_delete && i == idx_arg.elem (iidx))
+		iidx++;
+	      else
+		{
+		  T el = tmp.elem (i);
+		  if (el != T ())
+		    {
+		      data(ii) = el;
+		      ridx(ii++) = jj;
+		    }
+		  jj++;
+		}
+	    }
+
+	  dimensions.resize (2);
+
+	  if (nr == 1)
+	    {
+	      ii = 0;
+	      cidx(0) = 0;
+	      for (int i = 0; i < new_n; i++)
+		{
+		  OCTAVE_QUIT;
+		  if (ridx(ii) == i)
+		    ridx(ii++) = 0;
+		  cidx(i+1) = ii;
+		}
+
+	      dimensions(0) = 1;
+	      dimensions(1) = new_n;
+	    }
+	  else
+	    {
+	      cidx(0) = 0;
+	      cidx(1) = new_nnz;
+	      dimensions(0) = new_n;
+	      dimensions(1) = 1;
+	    }
+	}
+      else
+	(*current_liboctave_error_handler)
+	  ("A(idx) = []: index out of range");
+    }
+}
+
+template <class T>
+void
+Sparse<T>::maybe_delete_elements (idx_vector& idx_i, idx_vector& idx_j)
+{
+  assert (ndims () == 2);
+
+  int nr = dim1 ();
+  int nc = dim2 ();
+
+  if (nr == 0 && nc == 0)
+    return;
+
+  if (idx_i.is_colon ())
+    {
+      if (idx_j.is_colon ())
+	{
+	  // A(:,:) -- We are deleting columns and rows, so the result
+	  // is [](0x0).
+
+	  resize_no_fill (0, 0);
+	  return;
+	}
+
+      if (idx_j.is_colon_equiv (nc, 1))
+	{
+	  // A(:,j) -- We are deleting columns by enumerating them,
+	  // If we enumerate all of them, we should have zero columns
+	  // with the same number of rows that we started with.
+
+	  resize_no_fill (nr, 0);
+	  return;
+	}
+    }
+
+  if (idx_j.is_colon () && idx_i.is_colon_equiv (nr, 1))
+    {
+      // A(i,:) -- We are deleting rows by enumerating them.  If we
+      // enumerate all of them, we should have zero rows with the
+      // same number of columns that we started with.
+
+      resize_no_fill (0, nc);
+      return;
+    }
+
+  if (idx_i.is_colon_equiv (nr, 1))
+    {
+      if (idx_j.is_colon_equiv (nc, 1))
+	resize_no_fill (0, 0);
+      else
+	{
+	  idx_j.sort (true);
+
+	  int num_to_delete = idx_j.length (nc);
+
+	  if (num_to_delete != 0)
+	    {
+	      if (nr == 1 && num_to_delete == nc)
+		resize_no_fill (0, 0);
+	      else
+		{
+		  int new_nc = nc;
+		  int new_nnz = nnz ();
+
+		  int iidx = 0;
+
+		  for (int j = 0; j < nc; j++)
+		    {
+		      OCTAVE_QUIT;
+
+		      if (j == idx_j.elem (iidx))
+			{
+			  iidx++;
+			  new_nc--;
+			  
+			  new_nnz -= cidx(j+1) - cidx(j);
+
+			  if (iidx == num_to_delete)
+			    break;
+			}
+		    }
+
+		  if (new_nc > 0)
+		    {
+		      const Sparse<T> tmp (*this);
+		      --rep->count;
+		      rep = new typename Sparse<T>::SparseRep (nr, new_nc, 
+							       new_nnz);
+		      int ii = 0;
+		      int jj = 0;
+		      iidx = 0;
+		      cidx(0) = 0;
+		      for (int j = 0; j < nc; j++)
+			{
+			  OCTAVE_QUIT;
+
+			  if (iidx < num_to_delete && j == idx_j.elem (iidx))
+			    iidx++;
+			  else
+			    {
+			      for (int i = tmp.cidx(j); 
+				   i < tmp.cidx(j+1); i++)
+				{
+				  data(jj) = tmp.data(i);
+				  ridx(jj++) = tmp.ridx(i);
+				}
+			      cidx(++ii) = jj;
+			    }
+			}
+
+		      dimensions.resize (2);
+		      dimensions(1) = new_nc;
+		    }
+		  else
+		    (*current_liboctave_error_handler)
+		      ("A(idx) = []: index out of range");
+		}
+	    }
+	}
+    }
+  else if (idx_j.is_colon_equiv (nc, 1))
+    {
+      if (idx_i.is_colon_equiv (nr, 1))
+	resize_no_fill (0, 0);
+      else
+	{
+	  idx_i.sort (true);
+
+	  int num_to_delete = idx_i.length (nr);
+
+	  if (num_to_delete != 0)
+	    {
+	      if (nc == 1 && num_to_delete == nr)
+		resize_no_fill (0, 0);
+	      else
+		{
+		  int new_nr = nr;
+		  int new_nnz = nnz ();
+
+		  int iidx = 0;
+
+		  for (int i = 0; i < nr; i++)
+		    {
+		      OCTAVE_QUIT;
+
+		      if (i == idx_i.elem (iidx))
+			{
+			  iidx++;
+			  new_nr--;
+			  
+			  for (int j = 0; j < nnz (); j++)
+			    if (ridx(j) == i)
+			      new_nnz--;
+
+			  if (iidx == num_to_delete)
+			    break;
+			}
+		    }
+
+		  if (new_nr > 0)
+		    {
+		      const Sparse<T> tmp (*this);
+		      --rep->count;
+		      rep = new typename Sparse<T>::SparseRep (new_nr, nc, 
+							       new_nnz);
+
+		      int jj = 0;
+		      cidx(0) = 0;
+		      for (int i = 0; i < nc; i++)
+			{
+			  iidx = 0;
+			  for (int j = tmp.cidx(i); j < tmp.cidx(i+1); j++)
+			    {
+			      OCTAVE_QUIT;
+
+			      int ri = tmp.ridx(j);
+
+			      while (iidx < num_to_delete && 
+				     ri > idx_i.elem (iidx))
+				{
+				  iidx++;
+				}
+
+			      if (iidx == num_to_delete ||
+				  ri != idx_i.elem(iidx))
+				{
+				  data(jj) = tmp.data(j);
+				  ridx(jj++) = ri - iidx;
+				}
+			    }
+			  cidx(i+1) = jj;
+			}
+
+		      dimensions.resize (2);
+		      dimensions(0) = new_nr;
+		    }
+		  else
+		    (*current_liboctave_error_handler)
+		      ("A(idx) = []: index out of range");
+		}
+	    }
+	}
+    }
+}
+
+template <class T>
+void
+Sparse<T>::maybe_delete_elements (Array<idx_vector>& ra_idx)
+{
+  if (ra_idx.length () == 1)
+    maybe_delete_elements (ra_idx(0));
+  else if (ra_idx.length () == 2)
+    maybe_delete_elements (ra_idx(0), ra_idx(1));
+  else
+    (*current_liboctave_error_handler) 
+      ("range error for maybe_delete_elements");
+}
+
+template <class T>
+Sparse<T>
+Sparse<T>::value (void)
+{
+  Sparse<T> retval;
+
+  int n_idx = index_count ();
+
+  if (n_idx == 2)
+    {
+      idx_vector *tmp = get_idx ();
+
+      idx_vector idx_i = tmp[0];
+      idx_vector idx_j = tmp[1];
+
+      retval = index (idx_i, idx_j);
+    }
+  else if (n_idx == 1)
+    {
+      retval = index (idx[0]);
+    }
+  else
+    (*current_liboctave_error_handler)
+      ("Sparse<T>::value: invalid number of indices specified");
+
+  clear_index ();
+
+  return retval;
+}
+
+template <class T>
+Sparse<T>
+Sparse<T>::index (idx_vector& idx_arg, int resize_ok) const
+{
+  Sparse<T> retval;
+
+  assert (ndims () == 2);
+
+  int nr = dim1 ();
+  int nc = dim2 ();
+  int nz = nnz ();
+
+  int orig_len = nr * nc;
+
+  dim_vector idx_orig_dims = idx_arg.orig_dimensions ();
+
+  int idx_orig_rows = idx_arg.orig_rows ();
+  int idx_orig_columns = idx_arg.orig_columns ();
+
+  if (idx_orig_dims.length () > 2)
+    (*current_liboctave_error_handler)
+      ("Sparse<T>::index: Can not index Sparse<T> with an N-D Array");
+  else if (idx_arg.is_colon ())
+    {
+      // Fast magic colon processing.
+      retval = Sparse<T> (nr * nc, 1, nz);
+
+      for (int i = 0; i < nc; i++)
+	for (int j = cidx(i); j < cidx(i+1); j++)
+	  {
+	    OCTAVE_QUIT;
+	    retval.xdata(j) = data(j); 
+	    retval.xridx(j) = ridx(j) + i * nr;
+	  }
+      retval.xcidx(0) = 0;
+      retval.xcidx(1) = nz;
+    }
+  else if (nr == 1 && nc == 1)
+    {
+      // You have to be pretty sick to get to this bit of code,
+      // since you have a scalar stored as a sparse matrix, and
+      // then want to make a dense matrix with sparse 
+      // representation. Ok, we'll do it, but you deserve what 
+      // you get!!
+      int n = idx_arg.freeze (length (), "sparse vector", resize_ok);
+      if (n == 0)
+	if (idx_arg.one_zero_only ())
+	  retval = Sparse<T> (dim_vector (0, 0));
+	else
+	  retval = Sparse<T> (dim_vector (0, 1));
+      else if (nz < 1)
+	if (n >= idx_orig_dims.numel ())
+	  retval = Sparse<T> (idx_orig_dims);
+	else
+	  retval = Sparse<T> (dim_vector (n, 1));
+      else if (n >= idx_orig_dims.numel ())
+	{
+	  T el = elem (0);
+	  int new_nr = idx_orig_rows;
+	  int new_nc = idx_orig_columns;
+	  for (int i = 2; i < idx_orig_dims.length (); i++)
+	    new_nc *= idx_orig_dims (i);
+		
+	  retval = Sparse<T> (new_nr, new_nc, idx_arg.ones_count ());
+
+	  int ic = 0;
+	  for (int i = 0; i < n; i++)
+	    {
+	      if (i % new_nr == 0)
+		retval.xcidx(i % new_nr) = ic;
+
+	      int ii = idx_arg.elem (i);
+	      if (ii == 0)
+		{
+		  OCTAVE_QUIT;
+		  retval.xdata(ic) = el;
+		  retval.xridx(ic++) = i % new_nr;
+		}
+	    }
+	  retval.xcidx (new_nc) = ic;
+	}
+      else
+	{
+	  T el = elem (0);
+	  retval = Sparse<T> (n, 1, nz);
+  	 
+	  for (int i = 0; i < nz; i++) 
+	    {
+	      OCTAVE_QUIT;
+	      retval.xdata(i) = el;
+	      retval.xridx(i) = i;
+	    }
+	  retval.xcidx(0) = 0; 	 
+	  retval.xcidx(1) = n; 	 
+	}
+    }
+  else if (nr == 1 || nc == 1)
+    {
+      // If indexing a vector with a matrix, return value has same
+      // shape as the index.  Otherwise, it has same orientation as
+      // indexed object.
+      int len = length ();
+      int n = idx_arg.freeze (len, "sparse vector", resize_ok);
+
+      if (n == 0)
+	if (nr == 1)
+	  retval = Sparse<T> (dim_vector (1, 0));
+	else
+	  retval = Sparse<T> (dim_vector (0, 1));
+      else if (nz < 1)
+	if ((n != 0 && idx_arg.one_zero_only ())
+	    || idx_orig_rows == 1 || idx_orig_columns == 1)
+	  retval = Sparse<T> ((nr == 1 ? 1 : n), (nr == 1 ? n : 1));
+	else
+	  retval = Sparse<T> (idx_orig_dims);
+      else
+	{
+
+	  int new_nnz = 0;
+	  if (nr == 1)
+	    for (int i = 0; i < n; i++)
+	      {
+		OCTAVE_QUIT;
+
+		int ii = idx_arg.elem (i);
+		if (ii < len)
+		  if (cidx(ii) != cidx(ii+1))
+		    new_nnz++;
+	      }
+	  else
+	    for (int i = 0; i < n; i++)
+	      {
+		int ii = idx_arg.elem (i);
+		if (ii < len)
+		  for (int j = 0; j < nz; j++)
+		    {
+		      OCTAVE_QUIT;
+
+		      if (ridx(j) == ii)
+			new_nnz++;
+		      if (ridx(j) >= ii)
+			break;
+		    }
+	      }
+
+	  if (idx_arg.one_zero_only () || idx_orig_rows == 1 || 
+	      idx_orig_columns == 1)
+	    {
+	      if (nr == 1)
+		{
+		  retval = Sparse<T> (1, n, new_nnz);
+		  int jj = 0;
+		  retval.xcidx(0) = 0;
+		  for (int i = 0; i < n; i++)
+		    {
+		      OCTAVE_QUIT;
+
+		      int ii = idx_arg.elem (i);
+		      if (ii < len)
+			if (cidx(ii) != cidx(ii+1))
+			  {
+			    retval.xdata(jj) = data(cidx(ii));
+			    retval.xridx(jj++) = 0;
+			  }
+		      retval.xcidx(i+1) = jj;
+		    }
+		}
+	      else
+		{
+		  retval = Sparse<T> (n, 1, new_nnz);
+		  retval.xcidx(0) = 0;
+		  retval.xcidx(1) = new_nnz;
+		  int jj = 0;
+		  for (int i = 0; i < n; i++)
+		    {
+		      int ii = idx_arg.elem (i);
+		      if (ii < len)
+			for (int j = 0; j < nz; j++)
+			  {
+			    OCTAVE_QUIT;
+
+			    if (ridx(j) == ii)
+			      {
+				retval.xdata(jj) = data(j);
+				retval.xridx(jj++) = i;
+			      }
+			    if (ridx(j) >= ii)
+			      break;
+			  }
+		    }
+		}
+	    }
+	  else 
+	    {
+	      int new_nr;
+	      int new_nc;
+	      if (n >= idx_orig_dims.numel ())
+		{
+		  new_nr = idx_orig_rows;
+		  new_nc = idx_orig_columns;
+		}
+	      else
+		{
+		  new_nr = n;
+		  new_nc = 1;
+		}
+
+	      retval = Sparse<T> (new_nr, new_nc, new_nnz);
+
+	      if (nr == 1)
+		{
+		  int jj = 0;
+		  retval.xcidx(0) = 0;
+		  for (int i = 0; i < n; i++)
+		    {
+		      OCTAVE_QUIT;
+
+		      int ii = idx_arg.elem (i);
+		      if (ii < len)
+			if (cidx(ii) != cidx(ii+1))
+			  {
+			    retval.xdata(jj) = data(cidx(ii));
+			    retval.xridx(jj++) = 0;
+			  }
+		      retval.xcidx(i/new_nr+1) = jj;
+		    }
+		}
+	      else
+		{
+		  int jj = 0;
+		  retval.xcidx(0) = 0;
+		  for (int i = 0; i < n; i++)
+		    {
+		      int ii = idx_arg.elem (i);
+		      if (ii < len)
+			for (int j = 0; j < nz; j++)
+			  {
+			    OCTAVE_QUIT;
+
+			    if (ridx(j) == ii)
+			      {
+				retval.xdata(jj) = data(j);
+				retval.xridx(jj++) = i;
+			      }
+			    if (ridx(j) >= ii)
+			      break;
+			  }
+		      retval.xcidx(i/new_nr+1) = jj;
+		    }
+		}
+	    }
+	}
+    }
+  else
+    {
+      if (liboctave_wfi_flag
+	  && ! (idx_arg.one_zero_only ()
+		&& idx_orig_rows == nr
+		&& idx_orig_columns == nc))
+	(*current_liboctave_warning_handler) 
+	  ("single index used for sparse matrix");
+
+      // This code is only for indexing matrices.  The vector
+      // cases are handled above.
+
+      idx_arg.freeze (nr * nc, "matrix", resize_ok);
+
+      if (idx_arg)
+	{
+	  int result_nr = idx_orig_rows;
+	  int result_nc = idx_orig_columns;
+
+	  if (idx_arg.one_zero_only ())
+	    {
+	      result_nr = idx_arg.ones_count ();
+	      result_nc = (result_nr > 0 ? 1 : 0);
+	    }
+
+	  if (nz < 1)
+	      retval = Sparse<T> (result_nr, result_nc);
+	  else
+	    {
+	      // Count number of non-zero elements
+	      int new_nnz = 0;
+	      int kk = 0;
+	      for (int j = 0; j < result_nc; j++)
+		{
+		  for (int i = 0; i < result_nr; i++)
+		    {
+		      OCTAVE_QUIT;
+		      
+		      int ii = idx_arg.elem (kk++);
+		      if (ii < orig_len)
+			{
+			  int fr = ii % nr;
+			  int fc = (ii - fr) / nr;
+			  for (int k = cidx(fc); k < cidx(fc+1); k++)
+			    {
+			      if (ridx(k) == fr)
+				new_nnz++;
+			      if (ridx(k) >= fr)
+				break;
+			    }
+			}
+		    }
+		}
+	      
+	      retval = Sparse<T> (result_nr, result_nc, new_nnz);
+
+	      kk = 0;
+	      int jj = 0;
+	      retval.xcidx(0) = 0;
+	      for (int j = 0; j < result_nc; j++)
+		{
+		  for (int i = 0; i < result_nr; i++)
+		    {
+		      OCTAVE_QUIT;
+
+		      int ii = idx_arg.elem (kk++);
+		      if (ii < orig_len)
+			{
+			  int fr = ii % nr;
+			  int fc = (ii - fr) / nr;
+			  for (int k = cidx(fc); k < cidx(fc+1); k++)
+			    {
+			      if (ridx(k) == fr)
+				{
+				  retval.xdata(jj) = data(k);
+				  retval.xridx(jj++) = i;
+				}
+			      if (ridx(k) >= fr)
+				break;
+			    }
+			}
+		    }
+		  retval.xcidx(j+1) = jj;
+		}
+	    }
+	  // idx_vector::freeze() printed an error message for us.
+	}
+    }
+
+  return retval;
+}
+
+template <class T>
+Sparse<T>
+Sparse<T>::index (idx_vector& idx_i, idx_vector& idx_j, int resize_ok) const
+{
+  Sparse<T> retval;
+
+  assert (ndims () == 2);
+
+  int nr = dim1 ();
+  int nc = dim2 ();
+
+  int n = idx_i.freeze (nr, "row", resize_ok);
+  int m = idx_j.freeze (nc, "column", resize_ok);
+
+  if (idx_i && idx_j)
+    {
+      if (idx_i.orig_empty () || idx_j.orig_empty () || n == 0 || m == 0)
+	{
+	  retval.resize_no_fill (n, m);
+	}
+      else if (idx_i.is_colon_equiv (nr) && idx_j.is_colon_equiv (nc))
+	{
+	  retval = *this;
+	}
+      else
+	{
+	  // First count the number of non-zero elements
+	  int new_nnz = 0;
+	  for (int j = 0; j < m; j++)
+	    {
+	      int jj = idx_j.elem (j);
+	      for (int i = 0; i < n; i++)
+		{
+		  OCTAVE_QUIT;
+
+		  int ii = idx_i.elem (i);
+		  if (ii < nr && jj < nc)
+		    {
+		      for (int k = cidx(jj); k < cidx(jj+1); k++)
+			{
+			  if (ridx(k) == ii)
+			    new_nnz++;
+			  if (ridx(k) >= ii)
+			    break;
+			}
+		    }
+		}
+	    }
+
+	  retval = Sparse<T> (n, m, new_nnz);
+
+	  int kk = 0;
+	  retval.xcidx(0) = 0;
+	  for (int j = 0; j < m; j++)
+	    {
+	      int jj = idx_j.elem (j);
+	      for (int i = 0; i < n; i++)
+		{
+		  OCTAVE_QUIT;
+
+		  int ii = idx_i.elem (i);
+		  if (ii < nr && jj < nc)
+		    {
+		      for (int k = cidx(jj); k < cidx(jj+1); k++)
+			{
+			  if (ridx(k) == ii)
+			    {
+			      retval.xdata(kk) = data(k);
+			      retval.xridx(kk++) = i;
+			    }
+			  if (ridx(k) >= ii)
+			    break;
+			}
+		    }
+		}
+	      retval.xcidx(j+1) = kk;
+	    }
+	}
+    }
+
+  // idx_vector::freeze() printed an error message for us.
+
+  return retval;
+}
+
+template <class T>
+Sparse<T>
+Sparse<T>::index (Array<idx_vector>& ra_idx, int resize_ok) const
+{
+
+  if (ra_idx.length () != 2)
+    {
+      (*current_liboctave_error_handler) ("range error for index");
+      return *this;
+    }
+
+  return index (ra_idx (0), ra_idx (1), resize_ok);
+}
+
+// XXX FIXME XXX
+// Unfortunately numel can overflow for very large but very sparse matrices.
+// For now just flag an error when this happens.
+template <class LT, class RT>
+int
+assign1 (Sparse<LT>& lhs, const Sparse<RT>& rhs)
+{
+  int retval = 1;
+
+  idx_vector *idx_tmp = lhs.get_idx ();
+
+  idx_vector lhs_idx = idx_tmp[0];
+
+  int lhs_len = lhs.numel ();
+  int rhs_len = rhs.numel ();
+
+  unsigned EIGHT_BYTE_INT long_lhs_len = 
+    static_cast<unsigned EIGHT_BYTE_INT> (lhs.rows ()) *
+    static_cast<unsigned EIGHT_BYTE_INT> (lhs.cols ());
+
+  unsigned EIGHT_BYTE_INT long_rhs_len = 
+    static_cast<unsigned EIGHT_BYTE_INT> (rhs.rows ()) *
+    static_cast<unsigned EIGHT_BYTE_INT> (rhs.cols ());
+
+  if (long_rhs_len != static_cast<unsigned EIGHT_BYTE_INT>(rhs_len) ||
+      long_lhs_len != static_cast<unsigned EIGHT_BYTE_INT>(lhs_len))
+    {
+      (*current_liboctave_error_handler)
+	("A(I) = X: Matrix dimensions too large to ensure correct\n",
+	 "operation. This is an limitation that should be removed\n",
+	 "in the future.");
+
+      lhs.clear_index ();
+      return 0;
+    }
+
+  int nr = lhs.rows ();
+  int nc = lhs.cols ();
+  int nz = lhs.nnz ();
+
+  int n = lhs_idx.freeze (lhs_len, "vector", true, liboctave_wrore_flag);
+
+  if (n != 0)
+    {
+      int max_idx = lhs_idx.max () + 1;
+      max_idx = max_idx < lhs_len ? lhs_len : max_idx;
+
+      // Take a constant copy of lhs. This means that elem won't 
+      // create missing elements.
+      const Sparse<LT> c_lhs (lhs);
+
+      if (rhs_len == n)
+	{
+	  int new_nnz = lhs.nnz ();
+
+	  // First count the number of non-zero elements
+	  for (int i = 0; i < n; i++)
+	    {
+	      OCTAVE_QUIT;
+
+	      int ii = lhs_idx.elem (i);
+	      if (ii < lhs_len && c_lhs.elem(ii) != LT ())
+		new_nnz--;
+	      if (rhs.elem(i) != RT ())
+		new_nnz++;
+	    }
+
+	  if (nr > 1)
+	    {
+	      Sparse<LT> tmp (max_idx, 1, new_nnz);
+	      tmp.cidx(0) = 0;
+	      tmp.cidx(1) = tmp.nnz ();
+
+	      int i = 0;
+	      int ii = 0;
+	      if (i < nz)
+		ii = c_lhs.ridx(i);
+
+	      int j = 0;
+	      int jj = lhs_idx.elem(j);
+
+	      int kk = 0;
+
+	      while (j < n || i < nz)
+		{
+		  if (j == n || (i < nz && ii < jj))
+		    {
+		      tmp.xdata (kk) = c_lhs.data (i);
+		      tmp.xridx (kk++) = ii;
+		      if (++i < nz)
+			ii = c_lhs.ridx(i);
+		    }
+		  else
+		    {
+		      RT rtmp = rhs.elem (j);
+		      if (rtmp != RT ())
+			{
+			  tmp.xdata (kk) = rtmp;
+			  tmp.xridx (kk++) = jj;
+			}
+
+		      if (ii == jj && i < nz)
+			if (++i < nz)
+			  ii = c_lhs.ridx(i);
+		      if (++j < n)
+			jj = lhs_idx.elem(j);
+		    }
+		}
+
+	      lhs = tmp;
+	    }
+	  else
+	    {
+	      Sparse<LT> tmp (1, max_idx, new_nnz);
+
+	      int i = 0;
+	      int ii = 0;
+	      while (ii < nc && c_lhs.cidx(ii+1) <= i)
+		ii++;
+
+	      int j = 0;
+	      int jj = lhs_idx.elem(j);
+
+	      int kk = 0;
+	      int ic = 0;
+
+	      while (j < n || i < nz)
+		{
+		  if (j == n || (i < nz && ii < jj))
+		    {
+		      while (ic <= ii)
+			tmp.xcidx (ic++) = kk;
+		      tmp.xdata (kk) = c_lhs.data (i);
+		      i++;
+		      while (ii < nc && c_lhs.cidx(ii+1) <= i)
+			ii++;
+		    }
+		  else
+		    {
+		      while (ic <= jj)
+			tmp.xcidx (ic++) = kk;
+
+		      RT rtmp = rhs.elem (j);
+		      if (rtmp != RT ())
+			tmp.xdata (kk) = rtmp;
+		      if (ii == jj)
+			{
+			  i++;
+			  while (ii < nc && c_lhs.cidx(ii+1) <= i)
+			    ii++;
+			}
+		      j++;
+		      if (j < n)
+			jj = lhs_idx.elem(j);
+		    }
+		  tmp.xridx (kk++) = 0;
+		}
+
+	      for (int iidx = ic; iidx < max_idx+1; iidx++)
+		tmp.xcidx(iidx) = kk;
+
+	      lhs = tmp;
+	    }
+	}
+      else if (rhs_len == 1)
+	{
+	  int new_nnz = lhs.nnz ();
+	  RT scalar = rhs.elem (0);
+	  bool scalar_non_zero = (scalar != RT ());
+
+	  // First count the number of non-zero elements
+	  if (scalar != RT ())
+	    new_nnz += n;
+	  for (int i = 0; i < n; i++)
+	    {
+	      OCTAVE_QUIT;
+
+	      int ii = lhs_idx.elem (i);
+	      if (ii < lhs_len && c_lhs.elem(ii) != LT ())
+		new_nnz--;
+	    }
+
+	  if (nr > 1)
+	    {
+	      Sparse<LT> tmp (max_idx, 1, new_nnz);
+	      tmp.cidx(0) = 0;
+	      tmp.cidx(1) = tmp.nnz ();
+
+	      int i = 0;
+	      int ii = 0;
+	      if (i < nz)
+		ii = c_lhs.ridx(i);
+
+	      int j = 0;
+	      int jj = lhs_idx.elem(j);
+
+	      int kk = 0;
+
+	      while (j < n || i < nz)
+		{
+		  if (j == n || (i < nz && ii < jj))
+		    {
+		      tmp.xdata (kk) = c_lhs.data (i);
+		      tmp.xridx (kk++) = ii;
+		      if (++i < nz)
+			ii = c_lhs.ridx(i);
+		    }
+		  else
+		    {
+		      if (scalar_non_zero)
+			{
+			  tmp.xdata (kk) = scalar;
+			  tmp.xridx (kk++) = jj;
+			}
+
+		      if (ii == jj && i < nz)
+			if (++i < nz)
+			  ii = c_lhs.ridx(i);
+		      if (++j < n)
+			jj = lhs_idx.elem(j);
+		    }
+		}
+
+	      lhs = tmp;
+	    }
+	  else
+	    {
+	      Sparse<LT> tmp (1, max_idx, new_nnz);
+
+	      int i = 0;
+	      int ii = 0;
+	      while (ii < nc && c_lhs.cidx(ii+1) <= i)
+		ii++;
+
+	      int j = 0;
+	      int jj = lhs_idx.elem(j);
+
+	      int kk = 0;
+	      int ic = 0;
+
+	      while (j < n || i < nz)
+		{
+		  if (j == n || (i < nz && ii < jj))
+		    {
+		      while (ic <= ii)
+			tmp.xcidx (ic++) = kk;
+		      tmp.xdata (kk) = c_lhs.data (i);
+		      i++;
+		      while (ii < nc && c_lhs.cidx(ii+1) <= i)
+			ii++;
+		    }
+		  else
+		    {
+		      while (ic <= jj)
+			tmp.xcidx (ic++) = kk;
+		      if (scalar_non_zero)
+			tmp.xdata (kk) = scalar;
+		      if (ii == jj)
+			{
+			  i++;
+			  while (ii < nc && c_lhs.cidx(ii+1) <= i)
+			    ii++;
+			}
+		      j++;
+		      if (j < n)
+			jj = lhs_idx.elem(j);
+		    }
+		  tmp.xridx (kk++) = 0;
+		}
+
+	      for (int iidx = ic; iidx < max_idx+1; iidx++)
+		tmp.xcidx(iidx) = kk;
+
+	      lhs = tmp;
+	    }
+	}
+      else
+	{
+	  (*current_liboctave_error_handler)
+	    ("A(I) = X: X must be a scalar or a vector with same length as I");
+
+	  retval = 0;
+	}
+    }
+  else if (lhs_idx.is_colon ())
+    {
+      if (lhs_len == 0)
+	{
+
+	  int new_nnz = rhs.nnz ();
+	  Sparse<LT> tmp (1, rhs_len, new_nnz);
+
+	  int ii = 0;
+	  int jj = 0;
+	  for (int i = 0; i < rhs.cols(); i++)
+	    for (int j = rhs.cidx(i); j < rhs.cidx(i+1); j++)
+	      {
+		OCTAVE_QUIT;
+		for (int k = jj; k <= i * rhs.rows() + rhs.ridx(j); k++)
+		  tmp.cidx(jj++) = ii;
+
+		tmp.data(ii) = rhs.data(j);
+		tmp.ridx(ii++) = 0;
+	      }
+
+	  for (int i = jj; i < rhs_len + 1; i++)
+	    tmp.cidx(i) = ii;
+
+	  lhs = tmp;
+	}
+      else
+	(*current_liboctave_error_handler)
+	  ("A(:) = X: A must be the same size as X");
+    }
+  else if (! (rhs_len == 1 || rhs_len == 0))
+    {
+      (*current_liboctave_error_handler)
+	("A([]) = X: X must also be an empty matrix or a scalar");
+
+      retval = 0;
+    }
+
+  lhs.clear_index ();
+
+  return retval;
+}
+
+template <class LT, class RT>
+int
+assign (Sparse<LT>& lhs, const Sparse<RT>& rhs)
+{
+  int retval = 1;
+
+  int n_idx = lhs.index_count ();
+
+  int lhs_nr = lhs.rows ();
+  int lhs_nc = lhs.cols ();
+  int lhs_nz = lhs.nnz ();
+
+  int rhs_nr = rhs.rows ();
+  int rhs_nc = rhs.cols ();
+
+  idx_vector *tmp = lhs.get_idx ();
+
+  idx_vector idx_i;
+  idx_vector idx_j;
+
+  if (n_idx > 2)
+    {
+      (*current_liboctave_error_handler)
+        ("A(I, J) = X: can only have 1 or 2 indexes for sparse matrices");
+      return 0;
+    }
+
+  if (n_idx > 1)
+    idx_j = tmp[1];
+
+  if (n_idx > 0)
+    idx_i = tmp[0];
+
+  if (n_idx == 2)
+    {
+      int n = idx_i.freeze (lhs_nr, "row", true, liboctave_wrore_flag);
+      idx_i.sort (true);
+
+      int m = idx_j.freeze (lhs_nc, "column", true, liboctave_wrore_flag);
+      idx_j.sort (true);
+
+
+      int idx_i_is_colon = idx_i.is_colon ();
+      int idx_j_is_colon = idx_j.is_colon ();
+
+      if (idx_i_is_colon)
+	n = lhs_nr > 0 ? lhs_nr : rhs_nr;
+
+      if (idx_j_is_colon)
+	m = lhs_nc > 0 ? lhs_nc : rhs_nc;
+
+      if (idx_i && idx_j)
+	{
+	  if (rhs_nr == 0 && rhs_nc == 0)
+	    {
+	      lhs.maybe_delete_elements (idx_i, idx_j);
+	    }
+	  else
+	    {
+	      if (rhs_nr == 1 && rhs_nc == 1 && n >= 0 && m >= 0)
+		{
+		  // No need to do anything if either of the indices
+		  // are empty.
+
+		  if (n > 0 && m > 0)
+		    {
+		      int max_row_idx = idx_i_is_colon ? rhs_nr : 
+			idx_i.max () + 1;
+		      int max_col_idx = idx_j_is_colon ? rhs_nc : 
+			idx_j.max () + 1;
+		      int new_nr = max_row_idx > lhs_nr ? max_row_idx : 
+			lhs_nr;
+		      int new_nc = max_col_idx > lhs_nc ? max_col_idx : 
+			lhs_nc;
+		      RT scalar = rhs.elem (0, 0);
+
+		      // Count the number of non-zero terms
+		      int new_nnz = lhs.nnz ();
+		      for (int j = 0; j < m; j++)
+			{
+			  int jj = idx_j.elem (j);
+			  if (jj < lhs_nc)
+			    {
+			      for (int i = 0; i < n; i++)
+				{
+				  OCTAVE_QUIT;
+
+				  int ii = idx_i.elem (i);
+			      
+				  if (ii < lhs_nr)
+				    {
+				      for (int k = lhs.cidx(jj); 
+					   k < lhs.cidx(jj+1); k++)
+					{
+					  if (lhs.ridx(k) == ii)
+					    new_nnz--;
+					  if (lhs.ridx(k) >= ii)
+					    break;
+					}
+				    }
+				}
+			    }
+			}
+
+		      if (scalar != RT())
+			new_nnz += m * n;
+
+		      Sparse<LT> stmp (new_nr, new_nc, new_nnz);
+
+		      int jji = 0;
+		      int jj = idx_j.elem (jji);
+		      int kk = 0;
+		      stmp.cidx(0) = 0;
+		      for (int j = 0; j < new_nc; j++)
+			{
+			  if (jji < m && jj == j)
+			    {
+			      int iii = 0;
+			      int ii = idx_i.elem (iii);
+			      for (int i = 0; i < new_nr; i++)
+				{
+				  OCTAVE_QUIT;
+
+				  if (iii < n && ii == i)
+				    {
+				      if (scalar != RT ())
+					{
+					  stmp.data(kk) = scalar;
+					  stmp.ridx(kk++) = i;
+					}
+				      if (++iii < n)
+					ii = idx_i.elem(iii);
+				    }
+				  else if (j < lhs.cols()) 
+				    {
+				      for (int k = lhs.cidx(j); 
+					   k < lhs.cidx(j+1); k++)
+					{
+					  if (lhs.ridx(k) == i)
+					    {
+					      stmp.data(kk) = lhs.data(k);
+					      stmp.ridx(kk++) = i;
+					    }
+					  if (lhs.ridx(k) >= i)
+					    break;
+					}
+				    }
+				}
+			      if (++jji < m)
+				jj = idx_j.elem(jji);
+			    }
+			  else if (j < lhs.cols()) 
+			    {
+			      for (int i = lhs.cidx(j); 
+				   i < lhs.cidx(j+1); i++)
+				{
+				  stmp.data(kk) = lhs.data(i);
+				  stmp.ridx(kk++) = lhs.ridx(i);
+				}
+			    }
+			  stmp.cidx(j+1) = kk;
+			}
+		      
+		      lhs = stmp;
+		    }
+		}
+	      else if (n == rhs_nr && m == rhs_nc)
+		{
+		  if (n > 0 && m > 0)
+		    {
+		      int max_row_idx = idx_i_is_colon ? rhs_nr : 
+			idx_i.max () + 1;
+		      int max_col_idx = idx_j_is_colon ? rhs_nc : 
+			idx_j.max () + 1;
+		      int new_nr = max_row_idx > lhs_nr ? max_row_idx : 
+			lhs_nr;
+		      int new_nc = max_col_idx > lhs_nc ? max_col_idx : 
+			lhs_nc;
+
+		      // Count the number of non-zero terms
+		      int new_nnz = lhs.nnz ();
+		      for (int j = 0; j < m; j++)
+			{
+			  int jj = idx_j.elem (j);
+			  for (int i = 0; i < n; i++)
+			    {
+			      OCTAVE_QUIT;
+
+			      if (jj < lhs_nc)
+				{
+				  int ii = idx_i.elem (i);
+			      
+				  if (ii < lhs_nr)
+				    {
+				      for (int k = lhs.cidx(jj); 
+					   k < lhs.cidx(jj+1); k++)
+					{
+					  if (lhs.ridx(k) == ii)
+					    new_nnz--;
+					  if (lhs.ridx(k) >= ii)
+					    break;
+					}
+				    }
+				}
+			      
+			      if (rhs.elem(i,j) != RT ())
+				new_nnz++;
+			    }
+			}
+
+		      Sparse<LT> stmp (new_nr, new_nc, new_nnz);
+
+		      int jji = 0;
+		      int jj = idx_j.elem (jji);
+		      int kk = 0;
+		      stmp.cidx(0) = 0;
+		      for (int j = 0; j < new_nc; j++)
+			{
+			  if (jji < m && jj == j)
+			    {
+			      int iii = 0;
+			      int ii = idx_i.elem (iii);
+			      for (int i = 0; i < new_nr; i++)
+				{
+				  OCTAVE_QUIT;
+
+				  if (iii < n && ii == i)
+				    {
+				      RT rtmp = rhs.elem (iii, jji);
+				      if (rtmp != RT ())
+					{
+					  stmp.data(kk) = rtmp;
+					  stmp.ridx(kk++) = i;
+					}
+				      if (++iii < n)
+					ii = idx_i.elem(iii);
+				    }
+				  else if (j < lhs.cols()) 
+				    {
+				      for (int k = lhs.cidx(j); 
+					   k < lhs.cidx(j+1); k++)
+					{
+					  if (lhs.ridx(k) == i)
+					    {
+					      stmp.data(kk) = lhs.data(k);
+					      stmp.ridx(kk++) = i;
+					    }
+					  if (lhs.ridx(k) >= i)
+					    break;
+					}
+				    }
+				}
+			      if (++jji < m)
+				jj = idx_j.elem(jji);
+			    }
+			  else if (j < lhs.cols()) 
+			    {
+			      for (int i = lhs.cidx(j); 
+				   i < lhs.cidx(j+1); i++)
+				{
+				  stmp.data(kk) = lhs.data(i);
+				  stmp.ridx(kk++) = lhs.ridx(i);
+				}
+			    }
+			  stmp.cidx(j+1) = kk;
+			}
+
+		      lhs = stmp;
+		    }
+		}
+	      else if (n == 0 && m == 0)
+		{
+		  if (! ((rhs_nr == 1 && rhs_nc == 1)
+			 || (rhs_nr == 0 || rhs_nc == 0)))
+		    {
+		      (*current_liboctave_error_handler)
+		("A([], []) = X: X must be an empty matrix or a scalar");
+
+		      retval = 0;
+		    }
+		}
+	      else
+		{
+		  (*current_liboctave_error_handler)
+    ("A(I, J) = X: X must be a scalar or the number of elements in I must");
+		  (*current_liboctave_error_handler)
+    ("match the number of rows in X and the number of elements in J must");
+		  (*current_liboctave_error_handler)
+    ("match the number of columns in X");
+
+		  retval = 0;
+		}
+	    }
+	}
+      // idx_vector::freeze() printed an error message for us.
+    }
+  else if (n_idx == 1)
+    {
+      int lhs_is_empty = lhs_nr == 0 || lhs_nc == 0;
+
+      if (lhs_is_empty || (lhs_nr == 1 && lhs_nc == 1))
+	{
+	  int lhs_len = lhs.length ();
+
+	  int n = idx_i.freeze (lhs_len, 0, true, liboctave_wrore_flag);
+	  idx_i.sort (true);
+
+	  if (idx_i)
+	    {
+	      if (rhs_nr == 0 && rhs_nc == 0)
+		{
+		  if (n != 0 && (lhs_nr != 0 || lhs_nc != 0))
+		    lhs.maybe_delete_elements (idx_i);
+		}
+	      else
+		{
+		  if (liboctave_wfi_flag)
+		    {
+		      if (lhs_is_empty
+			  && idx_i.is_colon ()
+			  && ! (rhs_nr == 1 || rhs_nc == 1))
+			{
+			  (*current_liboctave_warning_handler)
+			    ("A(:) = X: X is not a vector or scalar");
+			}
+		      else
+			{
+			  int idx_nr = idx_i.orig_rows ();
+			  int idx_nc = idx_i.orig_columns ();
+
+			  if (! (rhs_nr == idx_nr && rhs_nc == idx_nc))
+			    (*current_liboctave_warning_handler)
+			      ("A(I) = X: X does not have same shape as I");
+			}
+		    }
+
+		  if (! assign1 ((Sparse<LT>&) lhs, (Sparse<RT>&) rhs))
+		    retval = 0;
+		}
+	    }
+	  // idx_vector::freeze() printed an error message for us.
+	}
+      else if (lhs_nr == 1)
+	{
+	  idx_i.freeze (lhs_nc, "vector", true, liboctave_wrore_flag);
+	  idx_i.sort (true);
+
+	  if (idx_i)
+	    {
+	      if (rhs_nr == 0 && rhs_nc == 0)
+		lhs.maybe_delete_elements (idx_i);
+	      else if (! assign1 ((Sparse<LT>&) lhs, (Sparse<RT>&) rhs))
+		retval = 0;
+	    }
+	  // idx_vector::freeze() printed an error message for us.
+	}
+      else if (lhs_nc == 1)
+	{
+	  idx_i.freeze (lhs_nr, "vector", true, liboctave_wrore_flag);
+	  idx_i.sort (true);
+
+	  if (idx_i)
+	    {
+	      if (rhs_nr == 0 && rhs_nc == 0)
+		lhs.maybe_delete_elements (idx_i);
+	      else if (! assign1 ((Sparse<LT>&) lhs, (Sparse<RT>&) rhs))
+		retval = 0;
+	    }
+	  // idx_vector::freeze() printed an error message for us.
+	}
+      else
+	{
+	  if (liboctave_wfi_flag
+	      && ! (idx_i.is_colon ()
+		    || (idx_i.one_zero_only ()
+			&& idx_i.orig_rows () == lhs_nr
+			&& idx_i.orig_columns () == lhs_nc)))
+	    (*current_liboctave_warning_handler)
+	      ("single index used for matrix");
+
+	  int lhs_len = lhs.length ();
+
+	  int len = idx_i.freeze (lhs_nr * lhs_nc, "matrix");
+	  idx_i.sort (true);
+
+	  if (idx_i)
+	    {
+	      // Take a constant copy of lhs. This means that elem won't 
+	      // create missing elements.
+	      const Sparse<LT> c_lhs (lhs);
+
+	      if (rhs_nr == 0 && rhs_nc == 0)
+		lhs.maybe_delete_elements (idx_i);
+	      else if (len == 0)
+		{
+		  if (! ((rhs_nr == 1 && rhs_nc == 1)
+			 || (rhs_nr == 0 || rhs_nc == 0)))
+		    (*current_liboctave_error_handler)
+		      ("A([]) = X: X must be an empty matrix or scalar");
+		}
+	      else if (len == rhs_nr * rhs_nc)
+		{
+		  int new_nnz = lhs_nz;
+
+		  // First count the number of non-zero elements
+		  for (int i = 0; i < len; i++)
+		    {
+		      OCTAVE_QUIT;
+		      
+		      int ii = idx_i.elem (i);
+		      if (ii < lhs_len && c_lhs.elem(ii) != LT ())
+			new_nnz--;
+		      if (rhs.elem(i) != RT ())
+			new_nnz++;
+		    }
+
+		  Sparse<LT> stmp (lhs_nr, lhs_nc, new_nnz);
+
+		  int i = 0;
+		  int ii = 0;
+		  int ic = 0;
+		  if (i < lhs_nz)
+		    {
+		      while (ic < lhs_nc && i >= c_lhs.cidx(ic+1))
+			ic++;
+		      ii = ic * lhs_nr + c_lhs.ridx(i);
+		    }
+
+		  int j = 0;
+		  int jj = idx_i.elem (j);
+		  int jr = jj % lhs_nr;
+		  int jc = (jj - jr) / lhs_nr;
+
+		  int kk = 0;
+		  int kc = 0;
+
+		  while (j < len || i < lhs_nz)
+		    {
+		      if (j == len || (i < lhs_nz && ii < jj))
+			{
+			  while (kc <= ic)
+			    stmp.xcidx (kc++) = kk;
+			  stmp.xdata (kk) = c_lhs.data (i);
+			  stmp.xridx (kk++) = c_lhs.ridx (i);
+			  i++;
+			  while (ic < lhs_nc && i >= c_lhs.cidx(ic+1))
+			    ic++;
+			  if (i < lhs_nz)
+			    ii = ic * lhs_nr + c_lhs.ridx(i);
+			}
+		      else
+			{
+			  while (kc <= jc)
+			    stmp.xcidx (kc++) = kk;
+			  RT rtmp = rhs.elem (j);
+			  if (rtmp != RT ())
+			    {
+			      stmp.xdata (kk) = rtmp;
+			      stmp.xridx (kk++) = jr;
+			    }
+			  if (ii == jj)
+			    {
+			      i++;
+			      while (ic < lhs_nc && i >= c_lhs.cidx(ic+1))
+				ic++;
+			      if (i < lhs_nz)
+				ii = ic * lhs_nr + c_lhs.ridx(i);
+			    }
+			  j++;
+			  if (j < len)
+			    {
+			      jj = idx_i.elem (j);
+			      jr = jj % lhs_nr;
+			      jc = (jj - jr) / lhs_nr;
+			    }
+			}
+		    }
+
+		  for (int iidx = kc; iidx < lhs_nc+1; iidx++)
+		    stmp.xcidx(iidx) = kk;
+		  
+
+		  lhs = stmp;
+		}
+	      else if (rhs_nr == 1 && rhs_nc == 1)
+		{
+		  RT scalar = rhs.elem (0, 0);
+		  int new_nnz = lhs_nz;
+
+		  // First count the number of non-zero elements
+		  if (scalar != RT ())
+		    new_nnz += len;
+		  for (int i = 0; i < len; i++)
+		    {
+		      OCTAVE_QUIT;
+		      int ii = idx_i.elem (i);
+		      if (ii < lhs_len && c_lhs.elem(ii) != LT ())
+			new_nnz--;
+		    }
+
+		  Sparse<LT> stmp (lhs_nr, lhs_nc, new_nnz);
+
+		  int i = 0;
+		  int ii = 0;
+		  int ic = 0;
+		  if (i < lhs_nz)
+		    {
+		      while (ic < lhs_nc && i >= c_lhs.cidx(ic+1))
+			ic++;
+		      ii = ic * lhs_nr + c_lhs.ridx(i);
+		    }
+
+		  int j = 0;
+		  int jj = idx_i.elem (j);
+		  int jr = jj % lhs_nr;
+		  int jc = (jj - jr) / lhs_nr;
+
+		  int kk = 0;
+		  int kc = 0;
+
+		  while (j < len || i < lhs_nz)
+		    {
+		      if (j == len || (i < lhs_nz && ii < jj))
+			{
+			  while (kc <= ic)
+			    stmp.xcidx (kc++) = kk;
+			  stmp.xdata (kk) = c_lhs.data (i);
+			  stmp.xridx (kk++) = c_lhs.ridx (i);
+			  i++;
+			  while (ic < lhs_nc && i >= c_lhs.cidx(ic+1))
+			    ic++;
+			  if (i < lhs_nz)
+			    ii = ic * lhs_nr + c_lhs.ridx(i);
+			}
+		      else
+			{
+			  while (kc <= jc)
+			    stmp.xcidx (kc++) = kk;
+			  if (scalar != RT ())
+			    {
+			      stmp.xdata (kk) = scalar;
+			      stmp.xridx (kk++) = jr;
+			    }
+			  if (ii == jj)
+			    {
+			      i++;
+			      while (ic < lhs_nc && i >= c_lhs.cidx(ic+1))
+				ic++;
+			      if (i < lhs_nz)
+				ii = ic * lhs_nr + c_lhs.ridx(i);
+			    }
+			  j++;
+			  if (j < len)
+			    {
+			      jj = idx_i.elem (j);
+			      jr = jj % lhs_nr;
+			      jc = (jj - jr) / lhs_nr;
+			    }
+			}
+		    }
+
+		  for (int iidx = kc; iidx < lhs_nc+1; iidx++)
+		    stmp.xcidx(iidx) = kk;
+		  
+		  lhs = stmp;
+		}
+	      else
+		{
+		  (*current_liboctave_error_handler)
+      ("A(I) = X: X must be a scalar or a matrix with the same size as I");
+
+		  retval = 0;
+		}
+	    }
+	  // idx_vector::freeze() printed an error message for us.
+	}
+    }
+  else
+    {
+      (*current_liboctave_error_handler)
+	("invalid number of indices for matrix expression");
+
+      retval = 0;
+    }
+
+  lhs.clear_index ();
+
+  return retval;
+}
+
+template <class T>
+void
+Sparse<T>::print_info (std::ostream& os, const std::string& prefix) const
+{
+  os << prefix << "rep address: " << rep << "\n"
+     << prefix << "rep->nnz:    " << rep->nnz << "\n"
+     << prefix << "rep->nrows:  " << rep->nrows << "\n"
+     << prefix << "rep->ncols:  " << rep->ncols << "\n"
+     << prefix << "rep->data:   " << static_cast<void *> (rep->d) << "\n"
+     << prefix << "rep->ridx:   " << static_cast<void *> (rep->r) << "\n"
+     << prefix << "rep->cidx:   " << static_cast<void *> (rep->c) << "\n"
+     << prefix << "rep->count:  " << rep->count << "\n";
+}
+
+/*
+;;; Local Variables: ***
+;;; mode: C++ ***
+;;; End: ***
+*/