view liboctave/numeric/lo-specfun.cc @ 21231:5f318c8ec634

eliminate feature tests from lo-specfun.h * lo-specfun.h, lo-specfun.cc (xacosh, xasinh, xatanh, xerf, xerfc xexpm1, xlog1p, xcbrt): Rename to have 'x' prefix. Conditionally define in .cc file. Change all uses Move complex versions of acosh, asinh, and atanh functions here.
author John W. Eaton <jwe@octave.org>
date Tue, 09 Feb 2016 04:15:50 -0500
parents f7121e111991
children 40de9f8f23a6
line wrap: on
line source

/*

Copyright (C) 1996-2015 John W. Eaton
Copyright (C) 2007-2010 D. Martin
Copyright (C) 2010 Jaroslav Hajek
Copyright (C) 2010 VZLU Prague
Copyright (C) 2015 Carnë Draug

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 "Range.h"
#include "CColVector.h"
#include "CMatrix.h"
#include "dRowVector.h"
#include "dMatrix.h"
#include "dNDArray.h"
#include "CNDArray.h"
#include "fCColVector.h"
#include "fCMatrix.h"
#include "fRowVector.h"
#include "fMatrix.h"
#include "fNDArray.h"
#include "fCNDArray.h"
#include "f77-fcn.h"
#include "lo-error.h"
#include "lo-ieee.h"
#include "lo-specfun.h"
#include "mx-inlines.cc"
#include "lo-mappers.h"
#include "lo-math.h"

#include "Faddeeva.hh"

extern "C"
{
  F77_RET_T
  F77_FUNC (zbesj, ZBESJ) (const double&, const double&, const double&,
                           const octave_idx_type&, const octave_idx_type&,
                           double*, double*, octave_idx_type&,
                           octave_idx_type&);

  F77_RET_T
  F77_FUNC (zbesy, ZBESY) (const double&, const double&, const double&,
                           const octave_idx_type&, const octave_idx_type&,
                           double*, double*, octave_idx_type&, double*,
                           double*, octave_idx_type&);

  F77_RET_T
  F77_FUNC (zbesi, ZBESI) (const double&, const double&, const double&,
                           const octave_idx_type&, const octave_idx_type&,
                           double*, double*, octave_idx_type&,
                           octave_idx_type&);

  F77_RET_T
  F77_FUNC (zbesk, ZBESK) (const double&, const double&, const double&,
                           const octave_idx_type&, const octave_idx_type&,
                           double*, double*, octave_idx_type&,
                           octave_idx_type&);

  F77_RET_T
  F77_FUNC (zbesh, ZBESH) (const double&, const double&, const double&,
                           const octave_idx_type&, const octave_idx_type&,
                           const octave_idx_type&, double*, double*,
                           octave_idx_type&, octave_idx_type&);

  F77_RET_T
  F77_FUNC (cbesj, cBESJ) (const FloatComplex&, const float&,
                           const octave_idx_type&, const octave_idx_type&,
                           FloatComplex*, octave_idx_type&, octave_idx_type&);

  F77_RET_T
  F77_FUNC (cbesy, CBESY) (const FloatComplex&, const float&,
                           const octave_idx_type&, const octave_idx_type&,
                           FloatComplex*, octave_idx_type&,
                           FloatComplex*, octave_idx_type&);

  F77_RET_T
  F77_FUNC (cbesi, CBESI) (const FloatComplex&, const float&,
                           const octave_idx_type&, const octave_idx_type&,
                           FloatComplex*, octave_idx_type&, octave_idx_type&);

  F77_RET_T
  F77_FUNC (cbesk, CBESK) (const FloatComplex&, const float&,
                           const octave_idx_type&, const octave_idx_type&,
                           FloatComplex*, octave_idx_type&, octave_idx_type&);

  F77_RET_T
  F77_FUNC (cbesh, CBESH) (const FloatComplex&, const float&,
                           const octave_idx_type&, const octave_idx_type&,
                           const octave_idx_type&, FloatComplex*,
                           octave_idx_type&, octave_idx_type&);

  F77_RET_T
  F77_FUNC (zairy, ZAIRY) (const double&, const double&,
                           const octave_idx_type&, const octave_idx_type&,
                           double&, double&, octave_idx_type&,
                           octave_idx_type&);

  F77_RET_T
  F77_FUNC (cairy, CAIRY) (const float&, const float&, const octave_idx_type&,
                           const octave_idx_type&, float&, float&,
                           octave_idx_type&, octave_idx_type&);

  F77_RET_T
  F77_FUNC (zbiry, ZBIRY) (const double&, const double&,
                           const octave_idx_type&, const octave_idx_type&,
                           double&, double&, octave_idx_type&);

  F77_RET_T
  F77_FUNC (cbiry, CBIRY) (const float&, const float&, const octave_idx_type&,
                           const octave_idx_type&, float&, float&,
                           octave_idx_type&);

  F77_RET_T
  F77_FUNC (xdacosh, XDACOSH) (const double&, double&);

  F77_RET_T
  F77_FUNC (xacosh, XACOSH) (const float&, float&);

  F77_RET_T
  F77_FUNC (xdasinh, XDASINH) (const double&, double&);

  F77_RET_T
  F77_FUNC (xasinh, XASINH) (const float&, float&);

  F77_RET_T
  F77_FUNC (xdatanh, XDATANH) (const double&, double&);

  F77_RET_T
  F77_FUNC (xatanh, XATANH) (const float&, float&);

  F77_RET_T
  F77_FUNC (xderf, XDERF) (const double&, double&);

  F77_RET_T
  F77_FUNC (xerf, XERF) (const float&, float&);

  F77_RET_T
  F77_FUNC (xderfc, XDERFC) (const double&, double&);

  F77_RET_T
  F77_FUNC (xerfc, XERFC) (const float&, float&);

  F77_RET_T
  F77_FUNC (xdbetai, XDBETAI) (const double&, const double&,
                               const double&, double&);

  F77_RET_T
  F77_FUNC (xbetai, XBETAI) (const float&, const float&,
                             const float&, float&);

  F77_RET_T
  F77_FUNC (xdgamma, XDGAMMA) (const double&, double&);

  F77_RET_T
  F77_FUNC (xgamma, XGAMMA) (const float&, float&);

  F77_RET_T
  F77_FUNC (xgammainc, XGAMMAINC) (const double&, const double&, double&);

  F77_RET_T
  F77_FUNC (xsgammainc, XSGAMMAINC) (const float&, const float&, float&);

  F77_RET_T
  F77_FUNC (dlgams, DLGAMS) (const double&, double&, double&);

  F77_RET_T
  F77_FUNC (algams, ALGAMS) (const float&, float&, float&);

  F77_RET_T
  F77_FUNC (psifn, PSIFN) (const float*, const octave_idx_type&,
                           const octave_idx_type&, const octave_idx_type&,
                           float*, octave_idx_type*, octave_idx_type*);

  F77_RET_T
  F77_FUNC (dpsifn, DPSIFN) (const double*, const octave_idx_type&,
                             const octave_idx_type&, const octave_idx_type&,
                             double*, octave_idx_type*, octave_idx_type*);
}

double
xacosh (double x)
{
#if defined (HAVE_ACOSH)
  return acosh (x);
#else
  double retval;
  F77_XFCN (xdacosh, XDACOSH, (x, retval));
  return retval;
#endif
}

float
xacosh (float x)
{
#if defined (HAVE_ACOSHF)
  return acoshf (x);
#else
  float retval;
  F77_XFCN (xacosh, XACOSH, (x, retval));
  return retval;
#endif
}

Complex
xacosh (const Complex& x)
{
  return log (x + sqrt (x + 1.0) * sqrt (x - 1.0));
}

FloatComplex
xacosh (const FloatComplex& x)
{
  return log (x + sqrt (x + 1.0f) * sqrt (x - 1.0f));
}

double
xasinh (double x)
{
#if defined (HAVE_ASINH)
  return asinh (x);
#else
  double retval;
  F77_XFCN (xdasinh, XDASINH, (x, retval));
  return retval;
#endif
}

float
xasinh (float x)
{
#if defined (HAVE_ASINHF)
  return asinhf (x);
#else
  float retval;
  F77_XFCN (xasinh, XASINH, (x, retval));
  return retval;
#endif
}

Complex
xasinh (const Complex& x)
{
  return log (x + sqrt (x*x + 1.0));
}

FloatComplex
xasinh (const FloatComplex& x)
{
  return log (x + sqrt (x*x + 1.0f));
}

double
xatanh (double x)
{
#if defined (HAVE_ATANH)
  return atanh (x);
#else
  double retval;
  F77_XFCN (xdatanh, XDATANH, (x, retval));
  return retval;
#endif
}

float
xatanh (float x)
{
#if defined (HAVE_ATANHF)
  return atanhf (x);
#else
  float retval;
  F77_XFCN (xatanh, XATANH, (x, retval));
  return retval;
#endif
}

Complex
xatanh (const Complex& x)
{
  return log ((1.0 + x) / (1.0 - x)) / 2.0;
}

FloatComplex
xatanh (const FloatComplex& x)
{
  return log ((1.0f + x) / (1.0f - x)) / 2.0f;
}

double
xerf (double x)
{
#if defined (HAVE_ERF)
  return erf (x);
#else
  double retval;
  F77_XFCN (xderf, XDERF, (x, retval));
  return retval;
#endif
}

float
xerf (float x)
{
#if defined (HAVE_ERFF)
  return erff (x);
#else
  float retval;
  F77_XFCN (xerf, XERF, (x, retval));
  return retval;
#endif
}

// Complex error function from the Faddeeva package
Complex
xerf (const Complex& x)
{
  return Faddeeva::erf (x);
}

FloatComplex
xerf (const FloatComplex& x)
{
  Complex xd (real (x), imag (x));
  Complex ret = Faddeeva::erf (xd, std::numeric_limits<float>::epsilon ());
  return FloatComplex (real (ret), imag (ret));
}

double
xerfc (double x)
{
#if defined (HAVE_ERFC)
  return erfc (x);
#else
  double retval;
  F77_XFCN (xderfc, XDERFC, (x, retval));
  return retval;
#endif
}

float
xerfc (float x)
{
#if defined (HAVE_ERFCF)
  return erfcf (x);
#else
  float retval;
  F77_XFCN (xerfc, XERFC, (x, retval));
  return retval;
#endif
}

// Complex complementary error function from the Faddeeva package
Complex
xerfc (const Complex& x)
{
  return Faddeeva::erfc (x);
}

FloatComplex
xerfc (const FloatComplex& x)
{
  Complex xd (real (x), imag (x));
  Complex ret = Faddeeva::erfc (xd, std::numeric_limits<float>::epsilon ());
  return FloatComplex (real (ret), imag (ret));
}

// Real and complex scaled complementary error function from Faddeeva package
float erfcx (float x) { return Faddeeva::erfcx(x); }
double erfcx (double x) { return Faddeeva::erfcx(x); }
Complex
erfcx (const Complex& x)
{
  return Faddeeva::erfcx (x);
}
FloatComplex
erfcx (const FloatComplex& x)
{
  Complex xd (real (x), imag (x));
  Complex ret = Faddeeva::erfcx (xd, std::numeric_limits<float>::epsilon ());
  return FloatComplex (real (ret), imag (ret));
}

// Real and complex imaginary error function from Faddeeva package
float erfi (float x) { return Faddeeva::erfi(x); }
double erfi (double x) { return Faddeeva::erfi(x); }
Complex
erfi (const Complex& x)
{
  return Faddeeva::erfi (x);
}
FloatComplex
erfi (const FloatComplex& x)
{
  Complex xd (real (x), imag (x));
  Complex ret = Faddeeva::erfi (xd, std::numeric_limits<float>::epsilon ());
  return FloatComplex (real (ret), imag (ret));
}

// Real and complex Dawson function (= scaled erfi) from Faddeeva package
float dawson (float x) { return Faddeeva::Dawson(x); }
double dawson (double x) { return Faddeeva::Dawson(x); }
Complex
dawson (const Complex& x)
{
  return Faddeeva::Dawson (x);
}
FloatComplex
dawson (const FloatComplex& x)
{
  Complex xd (real (x), imag (x));
  Complex ret = Faddeeva::Dawson (xd, std::numeric_limits<float>::epsilon ());
  return FloatComplex (real (ret), imag (ret));
}

double
xgamma (double x)
{
  double result;

  // Special cases for (near) compatibility with Matlab instead of
  // tgamma.  Matlab does not have -0.

  if (x == 0)
    result = xnegative_sign (x) ? -octave_Inf : octave_Inf;
  else if ((x < 0 && D_NINT (x) == x) || xisinf (x))
    result = octave_Inf;
  else if (xisnan (x))
    result = octave_NaN;
  else
    {
#if defined (HAVE_TGAMMA)
      result = tgamma (x);
#else
      F77_XFCN (xdgamma, XDGAMMA, (x, result));
#endif
    }

  return result;
}

double
xlgamma (double x)
{
#if defined (HAVE_LGAMMA)
  return lgamma (x);
#else
  double result;
  double sgngam;

  if (xisnan (x))
    result = x;
  else if ((x <= 0 && D_NINT (x) == x) || xisinf (x))
    result = octave_Inf;
  else
    F77_XFCN (dlgams, DLGAMS, (x, result, sgngam));

  return result;
#endif
}

Complex
rc_lgamma (double x)
{
  double result;

#if defined (HAVE_LGAMMA_R)
  int sgngam;
  result = lgamma_r (x, &sgngam);
#else
  double sgngam;

  if (xisnan (x))
    result = x;
  else if ((x <= 0 && D_NINT (x) == x) || xisinf (x))
    result = octave_Inf;
  else
    F77_XFCN (dlgams, DLGAMS, (x, result, sgngam));

#endif

  if (sgngam < 0)
    return result + Complex (0., M_PI);
  else
    return result;
}

float
xgamma (float x)
{
  float result;

  // Special cases for (near) compatibility with Matlab instead of
  // tgamma.  Matlab does not have -0.

  if (x == 0)
    result = xnegative_sign (x) ? -octave_Float_Inf : octave_Float_Inf;
  else if ((x < 0 && D_NINT (x) == x) || xisinf (x))
    result = octave_Float_Inf;
  else if (xisnan (x))
    result = octave_Float_NaN;
  else
    {
#if defined (HAVE_TGAMMA)
      result = tgammaf (x);
#else
      F77_XFCN (xgamma, XGAMMA, (x, result));
#endif
    }

  return result;
}

float
xlgamma (float x)
{
#if defined (HAVE_LGAMMAF)
  return lgammaf (x);
#else
  float result;
  float sgngam;

  if (xisnan (x))
    result = x;
  else if ((x <= 0 && D_NINT (x) == x) || xisinf (x))
    result = octave_Float_Inf;
  else
    F77_XFCN (algams, ALGAMS, (x, result, sgngam));

  return result;
#endif
}

FloatComplex
rc_lgamma (float x)
{
  float result;

#if defined (HAVE_LGAMMAF_R)
  int sgngam;
  result = lgammaf_r (x, &sgngam);
#else
  float sgngam;

  if (xisnan (x))
    result = x;
  else if ((x <= 0 && D_NINT (x) == x) || xisinf (x))
    result = octave_Float_Inf;
  else
    F77_XFCN (algams, ALGAMS, (x, result, sgngam));

#endif

  if (sgngam < 0)
    return result + FloatComplex (0., M_PI);
  else
    return result;
}

double
xexpm1 (double x)
{
#if defined (HAVE_EXPM1)
  return expm1 (x);
#else
  double retval;

  double ax = fabs (x);

  if (ax < 0.1)
    {
      ax /= 16;

      // use Taylor series to calculate exp(x)-1.
      double t = ax;
      double s = 0;
      for (int i = 2; i < 7; i++)
        s += (t *= ax/i);
      s += ax;

      // use the identity (a+1)^2-1 = a*(a+2)
      double e = s;
      for (int i = 0; i < 4; i++)
        {
          s *= e + 2;
          e *= e + 2;
        }

      retval = (x > 0) ? s : -s / (1+s);
    }
  else
    retval = exp (x) - 1;

  return retval;
#endif
}

Complex
xexpm1 (const Complex& x)
{
  Complex retval;

  if (std:: abs (x) < 1)
    {
      double im = x.imag ();
      double u = xexpm1 (x.real ());
      double v = sin (im/2);
      v = -2*v*v;
      retval = Complex (u*v + u + v, (u+1) * sin (im));
    }
  else
    retval = std::exp (x) - Complex (1);

  return retval;
}

float
xexpm1 (float x)
{
#if defined (HAVE_EXPM1F)
  return expm1f (x);
#else
  float retval;

  float ax = fabs (x);

  if (ax < 0.1)
    {
      ax /= 16;

      // use Taylor series to calculate exp(x)-1.
      float t = ax;
      float s = 0;
      for (int i = 2; i < 7; i++)
        s += (t *= ax/i);
      s += ax;

      // use the identity (a+1)^2-1 = a*(a+2)
      float e = s;
      for (int i = 0; i < 4; i++)
        {
          s *= e + 2;
          e *= e + 2;
        }

      retval = (x > 0) ? s : -s / (1+s);
    }
  else
    retval = exp (x) - 1;

  return retval;
#endif
}

FloatComplex
xexpm1 (const FloatComplex& x)
{
  FloatComplex retval;

  if (std:: abs (x) < 1)
    {
      float im = x.imag ();
      float u = xexpm1 (x.real ());
      float v = sin (im/2);
      v = -2*v*v;
      retval = FloatComplex (u*v + u + v, (u+1) * sin (im));
    }
  else
    retval = std::exp (x) - FloatComplex (1);

  return retval;
}

double
xlog1p (double x)
{
#if defined (HAVE_LOG1P)
  return log1p (x);
#else
  double retval;

  double ax = fabs (x);

  if (ax < 0.2)
    {
      // approximation log (1+x) ~ 2*sum ((x/(2+x)).^ii ./ ii), ii = 1:2:2n+1
      double u = x / (2 + x), t = 1, s = 0;
      for (int i = 2; i < 12; i += 2)
        s += (t *= u*u) / (i+1);

      retval = 2 * (s + 1) * u;
    }
  else
    retval = gnulib::log (1 + x);

  return retval;
#endif
}

Complex
xlog1p (const Complex& x)
{
  Complex retval;

  double r = x.real (), i = x.imag ();

  if (fabs (r) < 0.5 && fabs (i) < 0.5)
    {
      double u = 2*r + r*r + i*i;
      retval = Complex (xlog1p (u / (1+sqrt (u+1))),
                        atan2 (1 + r, i));
    }
  else
    retval = std::log (Complex (1) + x);

  return retval;
}

template <typename T>
T
xxcbrt (T x)
{
  static const T one_third = 0.3333333333333333333f;
  if (xfinite (x))
    {
      // Use pow.
      T y = std::pow (std::abs (x), one_third) * signum (x);
      // Correct for better accuracy.
      return (x / (y*y) + y + y) / 3;
    }
  else
    return x;
}

double
xcbrt (double x)
{
#if defined (HAVE_CBRT)
  return cbrt (x);
#else
  return xxcbrt (x);
#endif
}

float
xlog1p (float x)
{
#if defined (HAVE_LOG1PF)
  return log1pf (x);
#else
  float retval;

  float ax = fabs (x);

  if (ax < 0.2)
    {
      // approximation log (1+x) ~ 2*sum ((x/(2+x)).^ii ./ ii), ii = 1:2:2n+1
      float u = x / (2 + x), t = 1.0f, s = 0;
      for (int i = 2; i < 12; i += 2)
        s += (t *= u*u) / (i+1);

      retval = 2 * (s + 1.0f) * u;
    }
  else
    retval = gnulib::logf (1.0f + x);

  return retval;
#endif
}

FloatComplex
xlog1p (const FloatComplex& x)
{
  FloatComplex retval;

  float r = x.real (), i = x.imag ();

  if (fabs (r) < 0.5 && fabs (i) < 0.5)
    {
      float u = 2*r + r*r + i*i;
      retval = FloatComplex (xlog1p (u / (1+sqrt (u+1))),
                             atan2 (1 + r, i));
    }
  else
    retval = std::log (FloatComplex (1) + x);

  return retval;
}

float
xcbrt (float x)
{
#if defined (HAVE_CBRTF)
  return cbrtf (x);
#else
  return xxcbrt (x);
#endif
}

static inline Complex
zbesj (const Complex& z, double alpha, int kode, octave_idx_type& ierr);

static inline Complex
zbesy (const Complex& z, double alpha, int kode, octave_idx_type& ierr);

static inline Complex
zbesi (const Complex& z, double alpha, int kode, octave_idx_type& ierr);

static inline Complex
zbesk (const Complex& z, double alpha, int kode, octave_idx_type& ierr);

static inline Complex
zbesh1 (const Complex& z, double alpha, int kode, octave_idx_type& ierr);

static inline Complex
zbesh2 (const Complex& z, double alpha, int kode, octave_idx_type& ierr);

static inline Complex
bessel_return_value (const Complex& val, octave_idx_type ierr)
{
  static const Complex inf_val = Complex (octave_Inf, octave_Inf);
  static const Complex nan_val = Complex (octave_NaN, octave_NaN);

  Complex retval;

  switch (ierr)
    {
    case 0:
    case 3:
      retval = val;
      break;

    case 2:
      retval = inf_val;
      break;

    default:
      retval = nan_val;
      break;
    }

  return retval;
}

static inline bool
is_integer_value (double x)
{
  return x == static_cast<double> (static_cast<long> (x));
}

static inline Complex
zbesj (const Complex& z, double alpha, int kode, octave_idx_type& ierr)
{
  Complex retval;

  if (alpha >= 0.0)
    {
      double yr = 0.0;
      double yi = 0.0;

      octave_idx_type nz;

      double zr = z.real ();
      double zi = z.imag ();

      F77_FUNC (zbesj, ZBESJ) (zr, zi, alpha, 2, 1, &yr, &yi, nz, ierr);

      if (kode != 2)
        {
          double expz = exp (std::abs (zi));
          yr *= expz;
          yi *= expz;
        }

      if (zi == 0.0 && zr >= 0.0)
        yi = 0.0;

      retval = bessel_return_value (Complex (yr, yi), ierr);
    }
  else if (is_integer_value (alpha))
    {
      // zbesy can overflow as z->0, and cause troubles for generic case below
      alpha = -alpha;
      Complex tmp = zbesj (z, alpha, kode, ierr);
      if ((static_cast<long> (alpha)) & 1)
        tmp = - tmp;
      retval = bessel_return_value (tmp, ierr);
    }
  else
    {
      alpha = -alpha;

      Complex tmp = cos (M_PI * alpha) * zbesj (z, alpha, kode, ierr);

      if (ierr == 0 || ierr == 3)
        {
          tmp -= sin (M_PI * alpha) * zbesy (z, alpha, kode, ierr);

          retval = bessel_return_value (tmp, ierr);
        }
      else
        retval = Complex (octave_NaN, octave_NaN);
    }

  return retval;
}

static inline Complex
zbesy (const Complex& z, double alpha, int kode, octave_idx_type& ierr)
{
  Complex retval;

  if (alpha >= 0.0)
    {
      double yr = 0.0;
      double yi = 0.0;

      octave_idx_type nz;

      double wr, wi;

      double zr = z.real ();
      double zi = z.imag ();

      ierr = 0;

      if (zr == 0.0 && zi == 0.0)
        {
          yr = -octave_Inf;
          yi = 0.0;
        }
      else
        {
          F77_FUNC (zbesy, ZBESY) (zr, zi, alpha, 2, 1, &yr, &yi, nz,
                                   &wr, &wi, ierr);

          if (kode != 2)
            {
              double expz = exp (std::abs (zi));
              yr *= expz;
              yi *= expz;
            }

          if (zi == 0.0 && zr >= 0.0)
            yi = 0.0;
        }

      return bessel_return_value (Complex (yr, yi), ierr);
    }
  else if (is_integer_value (alpha - 0.5))
    {
      // zbesy can overflow as z->0, and cause troubles for generic case below
      alpha = -alpha;
      Complex tmp = zbesj (z, alpha, kode, ierr);
      if ((static_cast<long> (alpha - 0.5)) & 1)
        tmp = - tmp;
      retval = bessel_return_value (tmp, ierr);
    }
  else
    {
      alpha = -alpha;

      Complex tmp = cos (M_PI * alpha) * zbesy (z, alpha, kode, ierr);

      if (ierr == 0 || ierr == 3)
        {
          tmp += sin (M_PI * alpha) * zbesj (z, alpha, kode, ierr);

          retval = bessel_return_value (tmp, ierr);
        }
      else
        retval = Complex (octave_NaN, octave_NaN);
    }

  return retval;
}

static inline Complex
zbesi (const Complex& z, double alpha, int kode, octave_idx_type& ierr)
{
  Complex retval;

  if (alpha >= 0.0)
    {
      double yr = 0.0;
      double yi = 0.0;

      octave_idx_type nz;

      double zr = z.real ();
      double zi = z.imag ();

      F77_FUNC (zbesi, ZBESI) (zr, zi, alpha, 2, 1, &yr, &yi, nz, ierr);

      if (kode != 2)
        {
          double expz = exp (std::abs (zr));
          yr *= expz;
          yi *= expz;
        }

      if (zi == 0.0 && zr >= 0.0)
        yi = 0.0;

      retval = bessel_return_value (Complex (yr, yi), ierr);
    }
  else if (is_integer_value (alpha))
    {
      // zbesi can overflow as z->0, and cause troubles for generic case below
      alpha = -alpha;
      Complex tmp = zbesi (z, alpha, kode, ierr);
      retval = bessel_return_value (tmp, ierr);
    }
  else
    {
      alpha = -alpha;

      Complex tmp = zbesi (z, alpha, kode, ierr);

      if (ierr == 0 || ierr == 3)
        {
          Complex tmp2 = (2.0 / M_PI) * sin (M_PI * alpha)
                         * zbesk (z, alpha, kode, ierr);

          if (kode == 2)
            {
              // Compensate for different scaling factor of besk.
              tmp2 *= exp (-z - std::abs (z.real ()));
            }

          tmp += tmp2;

          retval = bessel_return_value (tmp, ierr);
        }
      else
        retval = Complex (octave_NaN, octave_NaN);
    }

  return retval;
}

static inline Complex
zbesk (const Complex& z, double alpha, int kode, octave_idx_type& ierr)
{
  Complex retval;

  if (alpha >= 0.0)
    {
      double yr = 0.0;
      double yi = 0.0;

      octave_idx_type nz;

      double zr = z.real ();
      double zi = z.imag ();

      ierr = 0;

      if (zr == 0.0 && zi == 0.0)
        {
          yr = octave_Inf;
          yi = 0.0;
        }
      else
        {
          F77_FUNC (zbesk, ZBESK) (zr, zi, alpha, 2, 1, &yr, &yi, nz, ierr);

          if (kode != 2)
            {
              Complex expz = exp (-z);

              double rexpz = real (expz);
              double iexpz = imag (expz);

              double tmp = yr*rexpz - yi*iexpz;

              yi = yr*iexpz + yi*rexpz;
              yr = tmp;
            }

          if (zi == 0.0 && zr >= 0.0)
            yi = 0.0;
        }

      retval = bessel_return_value (Complex (yr, yi), ierr);
    }
  else
    {
      Complex tmp = zbesk (z, -alpha, kode, ierr);

      retval = bessel_return_value (tmp, ierr);
    }

  return retval;
}

static inline Complex
zbesh1 (const Complex& z, double alpha, int kode, octave_idx_type& ierr)
{
  Complex retval;

  if (alpha >= 0.0)
    {
      double yr = 0.0;
      double yi = 0.0;

      octave_idx_type nz;

      double zr = z.real ();
      double zi = z.imag ();

      F77_FUNC (zbesh, ZBESH) (zr, zi, alpha, 2, 1, 1, &yr, &yi, nz, ierr);

      if (kode != 2)
        {
          Complex expz = exp (Complex (0.0, 1.0) * z);

          double rexpz = real (expz);
          double iexpz = imag (expz);

          double tmp = yr*rexpz - yi*iexpz;

          yi = yr*iexpz + yi*rexpz;
          yr = tmp;
        }

      retval = bessel_return_value (Complex (yr, yi), ierr);
    }
  else
    {
      alpha = -alpha;

      static const Complex eye = Complex (0.0, 1.0);

      Complex tmp = exp (M_PI * alpha * eye) * zbesh1 (z, alpha, kode, ierr);

      retval = bessel_return_value (tmp, ierr);
    }

  return retval;
}

static inline Complex
zbesh2 (const Complex& z, double alpha, int kode, octave_idx_type& ierr)
{
  Complex retval;

  if (alpha >= 0.0)
    {
      double yr = 0.0;
      double yi = 0.0;

      octave_idx_type nz;

      double zr = z.real ();
      double zi = z.imag ();

      F77_FUNC (zbesh, ZBESH) (zr, zi, alpha, 2, 2, 1, &yr, &yi, nz, ierr);

      if (kode != 2)
        {
          Complex expz = exp (-Complex (0.0, 1.0) * z);

          double rexpz = real (expz);
          double iexpz = imag (expz);

          double tmp = yr*rexpz - yi*iexpz;

          yi = yr*iexpz + yi*rexpz;
          yr = tmp;
        }

      retval = bessel_return_value (Complex (yr, yi), ierr);
    }
  else
    {
      alpha = -alpha;

      static const Complex eye = Complex (0.0, 1.0);

      Complex tmp = exp (-M_PI * alpha * eye) * zbesh2 (z, alpha, kode, ierr);

      retval = bessel_return_value (tmp, ierr);
    }

  return retval;
}

typedef Complex (*dptr) (const Complex&, double, int, octave_idx_type&);

static inline Complex
do_bessel (dptr f, const char *, double alpha, const Complex& x,
           bool scaled, octave_idx_type& ierr)
{
  Complex retval;

  retval = f (x, alpha, (scaled ? 2 : 1), ierr);

  return retval;
}

static inline ComplexMatrix
do_bessel (dptr f, const char *, double alpha, const ComplexMatrix& x,
           bool scaled, Array<octave_idx_type>& ierr)
{
  octave_idx_type nr = x.rows ();
  octave_idx_type nc = x.cols ();

  ComplexMatrix retval (nr, nc);

  ierr.resize (dim_vector (nr, nc));

  for (octave_idx_type j = 0; j < nc; j++)
    for (octave_idx_type i = 0; i < nr; i++)
      retval(i,j) = f (x(i,j), alpha, (scaled ? 2 : 1), ierr(i,j));

  return retval;
}

static inline ComplexMatrix
do_bessel (dptr f, const char *, const Matrix& alpha, const Complex& x,
           bool scaled, Array<octave_idx_type>& ierr)
{
  octave_idx_type nr = alpha.rows ();
  octave_idx_type nc = alpha.cols ();

  ComplexMatrix retval (nr, nc);

  ierr.resize (dim_vector (nr, nc));

  for (octave_idx_type j = 0; j < nc; j++)
    for (octave_idx_type i = 0; i < nr; i++)
      retval(i,j) = f (x, alpha(i,j), (scaled ? 2 : 1), ierr(i,j));

  return retval;
}

static inline ComplexMatrix
do_bessel (dptr f, const char *fn, const Matrix& alpha,
           const ComplexMatrix& x, bool scaled, Array<octave_idx_type>& ierr)
{
  ComplexMatrix retval;

  octave_idx_type x_nr = x.rows ();
  octave_idx_type x_nc = x.cols ();

  octave_idx_type alpha_nr = alpha.rows ();
  octave_idx_type alpha_nc = alpha.cols ();

  if (x_nr != alpha_nr || x_nc != alpha_nc)
    (*current_liboctave_error_handler)
      ("%s: the sizes of alpha and x must conform", fn);

  octave_idx_type nr = x_nr;
  octave_idx_type nc = x_nc;

  retval.resize (nr, nc);

  ierr.resize (dim_vector (nr, nc));

  for (octave_idx_type j = 0; j < nc; j++)
    for (octave_idx_type i = 0; i < nr; i++)
      retval(i,j) = f (x(i,j), alpha(i,j), (scaled ? 2 : 1), ierr(i,j));

  return retval;
}

static inline ComplexNDArray
do_bessel (dptr f, const char *, double alpha, const ComplexNDArray& x,
           bool scaled, Array<octave_idx_type>& ierr)
{
  dim_vector dv = x.dims ();
  octave_idx_type nel = dv.numel ();
  ComplexNDArray retval (dv);

  ierr.resize (dv);

  for (octave_idx_type i = 0; i < nel; i++)
    retval(i) = f (x(i), alpha, (scaled ? 2 : 1), ierr(i));

  return retval;
}

static inline ComplexNDArray
do_bessel (dptr f, const char *, const NDArray& alpha, const Complex& x,
           bool scaled, Array<octave_idx_type>& ierr)
{
  dim_vector dv = alpha.dims ();
  octave_idx_type nel = dv.numel ();
  ComplexNDArray retval (dv);

  ierr.resize (dv);

  for (octave_idx_type i = 0; i < nel; i++)
    retval(i) = f (x, alpha(i), (scaled ? 2 : 1), ierr(i));

  return retval;
}

static inline ComplexNDArray
do_bessel (dptr f, const char *fn, const NDArray& alpha,
           const ComplexNDArray& x, bool scaled, Array<octave_idx_type>& ierr)
{
  dim_vector dv = x.dims ();
  ComplexNDArray retval;

  if (dv != alpha.dims ())
    (*current_liboctave_error_handler)
      ("%s: the sizes of alpha and x must conform", fn);

  octave_idx_type nel = dv.numel ();

  retval.resize (dv);
  ierr.resize (dv);

  for (octave_idx_type i = 0; i < nel; i++)
    retval(i) = f (x(i), alpha(i), (scaled ? 2 : 1), ierr(i));

  return retval;
}

static inline ComplexMatrix
do_bessel (dptr f, const char *, const RowVector& alpha,
           const ComplexColumnVector& x, bool scaled,
           Array<octave_idx_type>& ierr)
{
  octave_idx_type nr = x.numel ();
  octave_idx_type nc = alpha.numel ();

  ComplexMatrix retval (nr, nc);

  ierr.resize (dim_vector (nr, nc));

  for (octave_idx_type j = 0; j < nc; j++)
    for (octave_idx_type i = 0; i < nr; i++)
      retval(i,j) = f (x(i), alpha(j), (scaled ? 2 : 1), ierr(i,j));

  return retval;
}

#define SS_BESSEL(name, fcn) \
  Complex \
  name (double alpha, const Complex& x, bool scaled, octave_idx_type& ierr) \
  { \
    return do_bessel (fcn, #name, alpha, x, scaled, ierr); \
  }

#define SM_BESSEL(name, fcn) \
  ComplexMatrix \
  name (double alpha, const ComplexMatrix& x, bool scaled, \
        Array<octave_idx_type>& ierr) \
  { \
    return do_bessel (fcn, #name, alpha, x, scaled, ierr); \
  }

#define MS_BESSEL(name, fcn) \
  ComplexMatrix \
  name (const Matrix& alpha, const Complex& x, bool scaled, \
        Array<octave_idx_type>& ierr) \
  { \
    return do_bessel (fcn, #name, alpha, x, scaled, ierr); \
  }

#define MM_BESSEL(name, fcn) \
  ComplexMatrix \
  name (const Matrix& alpha, const ComplexMatrix& x, bool scaled, \
        Array<octave_idx_type>& ierr) \
  { \
    return do_bessel (fcn, #name, alpha, x, scaled, ierr); \
  }

#define SN_BESSEL(name, fcn) \
  ComplexNDArray \
  name (double alpha, const ComplexNDArray& x, bool scaled, \
        Array<octave_idx_type>& ierr) \
  { \
    return do_bessel (fcn, #name, alpha, x, scaled, ierr); \
  }

#define NS_BESSEL(name, fcn) \
  ComplexNDArray \
  name (const NDArray& alpha, const Complex& x, bool scaled, \
        Array<octave_idx_type>& ierr) \
  { \
    return do_bessel (fcn, #name, alpha, x, scaled, ierr); \
  }

#define NN_BESSEL(name, fcn) \
  ComplexNDArray \
  name (const NDArray& alpha, const ComplexNDArray& x, bool scaled, \
        Array<octave_idx_type>& ierr) \
  { \
    return do_bessel (fcn, #name, alpha, x, scaled, ierr); \
  }

#define RC_BESSEL(name, fcn) \
  ComplexMatrix \
  name (const RowVector& alpha, const ComplexColumnVector& x, bool scaled, \
        Array<octave_idx_type>& ierr) \
  { \
    return do_bessel (fcn, #name, alpha, x, scaled, ierr); \
  }

#define ALL_BESSEL(name, fcn) \
  SS_BESSEL (name, fcn) \
  SM_BESSEL (name, fcn) \
  MS_BESSEL (name, fcn) \
  MM_BESSEL (name, fcn) \
  SN_BESSEL (name, fcn) \
  NS_BESSEL (name, fcn) \
  NN_BESSEL (name, fcn) \
  RC_BESSEL (name, fcn)

ALL_BESSEL (besselj, zbesj)
ALL_BESSEL (bessely, zbesy)
ALL_BESSEL (besseli, zbesi)
ALL_BESSEL (besselk, zbesk)
ALL_BESSEL (besselh1, zbesh1)
ALL_BESSEL (besselh2, zbesh2)

#undef ALL_BESSEL
#undef SS_BESSEL
#undef SM_BESSEL
#undef MS_BESSEL
#undef MM_BESSEL
#undef SN_BESSEL
#undef NS_BESSEL
#undef NN_BESSEL
#undef RC_BESSEL

static inline FloatComplex
cbesj (const FloatComplex& z, float alpha, int kode, octave_idx_type& ierr);

static inline FloatComplex
cbesy (const FloatComplex& z, float alpha, int kode, octave_idx_type& ierr);

static inline FloatComplex
cbesi (const FloatComplex& z, float alpha, int kode, octave_idx_type& ierr);

static inline FloatComplex
cbesk (const FloatComplex& z, float alpha, int kode, octave_idx_type& ierr);

static inline FloatComplex
cbesh1 (const FloatComplex& z, float alpha, int kode, octave_idx_type& ierr);

static inline FloatComplex
cbesh2 (const FloatComplex& z, float alpha, int kode, octave_idx_type& ierr);

static inline FloatComplex
bessel_return_value (const FloatComplex& val, octave_idx_type ierr)
{
  static const FloatComplex inf_val = FloatComplex (octave_Float_Inf,
                                                    octave_Float_Inf);
  static const FloatComplex nan_val = FloatComplex (octave_Float_NaN,
                                                    octave_Float_NaN);

  FloatComplex retval;

  switch (ierr)
    {
    case 0:
    case 3:
      retval = val;
      break;

    case 2:
      retval = inf_val;
      break;

    default:
      retval = nan_val;
      break;
    }

  return retval;
}

static inline bool
is_integer_value (float x)
{
  return x == static_cast<float> (static_cast<long> (x));
}

static inline FloatComplex
cbesj (const FloatComplex& z, float alpha, int kode, octave_idx_type& ierr)
{
  FloatComplex retval;

  if (alpha >= 0.0)
    {
      FloatComplex y = 0.0;

      octave_idx_type nz;

      F77_FUNC (cbesj, CBESJ) (z, alpha, 2, 1, &y, nz, ierr);

      if (kode != 2)
        {
          float expz = exp (std::abs (imag (z)));
          y *= expz;
        }

      if (imag (z) == 0.0 && real (z) >= 0.0)
        y = FloatComplex (y.real (), 0.0);

      retval = bessel_return_value (y, ierr);
    }
  else if (is_integer_value (alpha))
    {
      // zbesy can overflow as z->0, and cause troubles for generic case below
      alpha = -alpha;
      FloatComplex tmp = cbesj (z, alpha, kode, ierr);
      if ((static_cast<long> (alpha)) & 1)
        tmp = - tmp;
      retval = bessel_return_value (tmp, ierr);
    }
  else
    {
      alpha = -alpha;

      FloatComplex tmp = cosf (static_cast<float> (M_PI) * alpha)
                         * cbesj (z, alpha, kode, ierr);

      if (ierr == 0 || ierr == 3)
        {
          tmp -= sinf (static_cast<float> (M_PI) * alpha)
                 * cbesy (z, alpha, kode, ierr);

          retval = bessel_return_value (tmp, ierr);
        }
      else
        retval = FloatComplex (octave_Float_NaN, octave_Float_NaN);
    }

  return retval;
}

static inline FloatComplex
cbesy (const FloatComplex& z, float alpha, int kode, octave_idx_type& ierr)
{
  FloatComplex retval;

  if (alpha >= 0.0)
    {
      FloatComplex y = 0.0;

      octave_idx_type nz;

      FloatComplex w;

      ierr = 0;

      if (real (z) == 0.0 && imag (z) == 0.0)
        {
          y = FloatComplex (-octave_Float_Inf, 0.0);
        }
      else
        {
          F77_FUNC (cbesy, CBESY) (z, alpha, 2, 1, &y, nz, &w, ierr);

          if (kode != 2)
            {
              float expz = exp (std::abs (imag (z)));
              y *= expz;
            }

          if (imag (z) == 0.0 && real (z) >= 0.0)
            y = FloatComplex (y.real (), 0.0);
        }

      return bessel_return_value (y, ierr);
    }
  else if (is_integer_value (alpha - 0.5))
    {
      // zbesy can overflow as z->0, and cause troubles for generic case below
      alpha = -alpha;
      FloatComplex tmp = cbesj (z, alpha, kode, ierr);
      if ((static_cast<long> (alpha - 0.5)) & 1)
        tmp = - tmp;
      retval = bessel_return_value (tmp, ierr);
    }
  else
    {
      alpha = -alpha;

      FloatComplex tmp = cosf (static_cast<float> (M_PI) * alpha)
                         * cbesy (z, alpha, kode, ierr);

      if (ierr == 0 || ierr == 3)
        {
          tmp += sinf (static_cast<float> (M_PI) * alpha)
                 * cbesj (z, alpha, kode, ierr);

          retval = bessel_return_value (tmp, ierr);
        }
      else
        retval = FloatComplex (octave_Float_NaN, octave_Float_NaN);
    }

  return retval;
}

static inline FloatComplex
cbesi (const FloatComplex& z, float alpha, int kode, octave_idx_type& ierr)
{
  FloatComplex retval;

  if (alpha >= 0.0)
    {
      FloatComplex y = 0.0;

      octave_idx_type nz;

      F77_FUNC (cbesi, CBESI) (z, alpha, 2, 1, &y, nz, ierr);

      if (kode != 2)
        {
          float expz = exp (std::abs (real (z)));
          y *= expz;
        }

      if (imag (z) == 0.0 && real (z) >= 0.0)
        y = FloatComplex (y.real (), 0.0);

      retval = bessel_return_value (y, ierr);
    }
  else
    {
      alpha = -alpha;

      FloatComplex tmp = cbesi (z, alpha, kode, ierr);

      if (ierr == 0 || ierr == 3)
        {
          FloatComplex tmp2 = static_cast<float> (2.0 / M_PI)
                              * sinf (static_cast<float> (M_PI) * alpha)
                              * cbesk (z, alpha, kode, ierr);

          if (kode == 2)
            {
              // Compensate for different scaling factor of besk.
              tmp2 *= exp (-z - std::abs (z.real ()));
            }

          tmp += tmp2;

          retval = bessel_return_value (tmp, ierr);
        }
      else
        retval = FloatComplex (octave_Float_NaN, octave_Float_NaN);
    }

  return retval;
}

static inline FloatComplex
cbesk (const FloatComplex& z, float alpha, int kode, octave_idx_type& ierr)
{
  FloatComplex retval;

  if (alpha >= 0.0)
    {
      FloatComplex y = 0.0;

      octave_idx_type nz;

      ierr = 0;

      if (real (z) == 0.0 && imag (z) == 0.0)
        {
          y = FloatComplex (octave_Float_Inf, 0.0);
        }
      else
        {
          F77_FUNC (cbesk, CBESK) (z, alpha, 2, 1, &y, nz, ierr);

          if (kode != 2)
            {
              FloatComplex expz = exp (-z);

              float rexpz = real (expz);
              float iexpz = imag (expz);

              float tmp_r = real (y) * rexpz - imag (y) * iexpz;
              float tmp_i = real (y) * iexpz + imag (y) * rexpz;

              y = FloatComplex (tmp_r, tmp_i);
            }

          if (imag (z) == 0.0 && real (z) >= 0.0)
            y = FloatComplex (y.real (), 0.0);
        }

      retval = bessel_return_value (y, ierr);
    }
  else
    {
      FloatComplex tmp = cbesk (z, -alpha, kode, ierr);

      retval = bessel_return_value (tmp, ierr);
    }

  return retval;
}

static inline FloatComplex
cbesh1 (const FloatComplex& z, float alpha, int kode, octave_idx_type& ierr)
{
  FloatComplex retval;

  if (alpha >= 0.0)
    {
      FloatComplex y = 0.0;

      octave_idx_type nz;

      F77_FUNC (cbesh, CBESH) (z, alpha, 2, 1, 1, &y, nz, ierr);

      if (kode != 2)
        {
          FloatComplex expz = exp (FloatComplex (0.0, 1.0) * z);

          float rexpz = real (expz);
          float iexpz = imag (expz);

          float tmp_r = real (y) * rexpz - imag (y) * iexpz;
          float tmp_i = real (y) * iexpz + imag (y) * rexpz;

          y = FloatComplex (tmp_r, tmp_i);
        }

      retval = bessel_return_value (y, ierr);
    }
  else
    {
      alpha = -alpha;

      static const FloatComplex eye = FloatComplex (0.0, 1.0);

      FloatComplex tmp = exp (static_cast<float> (M_PI) * alpha * eye)
                         * cbesh1 (z, alpha, kode, ierr);

      retval = bessel_return_value (tmp, ierr);
    }

  return retval;
}

static inline FloatComplex
cbesh2 (const FloatComplex& z, float alpha, int kode, octave_idx_type& ierr)
{
  FloatComplex retval;

  if (alpha >= 0.0)
    {
      FloatComplex y = 0.0;

      octave_idx_type nz;

      F77_FUNC (cbesh, CBESH) (z, alpha, 2, 2, 1, &y, nz, ierr);

      if (kode != 2)
        {
          FloatComplex expz = exp (-FloatComplex (0.0, 1.0) * z);

          float rexpz = real (expz);
          float iexpz = imag (expz);

          float tmp_r = real (y) * rexpz - imag (y) * iexpz;
          float tmp_i = real (y) * iexpz + imag (y) * rexpz;

          y = FloatComplex (tmp_r, tmp_i);
        }

      retval = bessel_return_value (y, ierr);
    }
  else
    {
      alpha = -alpha;

      static const FloatComplex eye = FloatComplex (0.0, 1.0);

      FloatComplex tmp = exp (-static_cast<float> (M_PI) * alpha * eye)
                         * cbesh2 (z, alpha, kode, ierr);

      retval = bessel_return_value (tmp, ierr);
    }

  return retval;
}

typedef FloatComplex (*fptr) (const FloatComplex&, float, int,
                              octave_idx_type&);

static inline FloatComplex
do_bessel (fptr f, const char *, float alpha, const FloatComplex& x,
           bool scaled, octave_idx_type& ierr)
{
  FloatComplex retval;

  retval = f (x, alpha, (scaled ? 2 : 1), ierr);

  return retval;
}

static inline FloatComplexMatrix
do_bessel (fptr f, const char *, float alpha, const FloatComplexMatrix& x,
           bool scaled, Array<octave_idx_type>& ierr)
{
  octave_idx_type nr = x.rows ();
  octave_idx_type nc = x.cols ();

  FloatComplexMatrix retval (nr, nc);

  ierr.resize (dim_vector (nr, nc));

  for (octave_idx_type j = 0; j < nc; j++)
    for (octave_idx_type i = 0; i < nr; i++)
      retval(i,j) = f (x(i,j), alpha, (scaled ? 2 : 1), ierr(i,j));

  return retval;
}

static inline FloatComplexMatrix
do_bessel (fptr f, const char *, const FloatMatrix& alpha,
           const FloatComplex& x,
           bool scaled, Array<octave_idx_type>& ierr)
{
  octave_idx_type nr = alpha.rows ();
  octave_idx_type nc = alpha.cols ();

  FloatComplexMatrix retval (nr, nc);

  ierr.resize (dim_vector (nr, nc));

  for (octave_idx_type j = 0; j < nc; j++)
    for (octave_idx_type i = 0; i < nr; i++)
      retval(i,j) = f (x, alpha(i,j), (scaled ? 2 : 1), ierr(i,j));

  return retval;
}

static inline FloatComplexMatrix
do_bessel (fptr f, const char *fn, const FloatMatrix& alpha,
           const FloatComplexMatrix& x, bool scaled,
           Array<octave_idx_type>& ierr)
{
  FloatComplexMatrix retval;

  octave_idx_type x_nr = x.rows ();
  octave_idx_type x_nc = x.cols ();

  octave_idx_type alpha_nr = alpha.rows ();
  octave_idx_type alpha_nc = alpha.cols ();

  if (x_nr != alpha_nr || x_nc != alpha_nc)
    (*current_liboctave_error_handler)
      ("%s: the sizes of alpha and x must conform", fn);

  octave_idx_type nr = x_nr;
  octave_idx_type nc = x_nc;

  retval.resize (nr, nc);

  ierr.resize (dim_vector (nr, nc));

  for (octave_idx_type j = 0; j < nc; j++)
    for (octave_idx_type i = 0; i < nr; i++)
      retval(i,j) = f (x(i,j), alpha(i,j), (scaled ? 2 : 1), ierr(i,j));

  return retval;
}

static inline FloatComplexNDArray
do_bessel (fptr f, const char *, float alpha, const FloatComplexNDArray& x,
           bool scaled, Array<octave_idx_type>& ierr)
{
  dim_vector dv = x.dims ();
  octave_idx_type nel = dv.numel ();
  FloatComplexNDArray retval (dv);

  ierr.resize (dv);

  for (octave_idx_type i = 0; i < nel; i++)
    retval(i) = f (x(i), alpha, (scaled ? 2 : 1), ierr(i));

  return retval;
}

static inline FloatComplexNDArray
do_bessel (fptr f, const char *, const FloatNDArray& alpha,
           const FloatComplex& x, bool scaled, Array<octave_idx_type>& ierr)
{
  dim_vector dv = alpha.dims ();
  octave_idx_type nel = dv.numel ();
  FloatComplexNDArray retval (dv);

  ierr.resize (dv);

  for (octave_idx_type i = 0; i < nel; i++)
    retval(i) = f (x, alpha(i), (scaled ? 2 : 1), ierr(i));

  return retval;
}

static inline FloatComplexNDArray
do_bessel (fptr f, const char *fn, const FloatNDArray& alpha,
           const FloatComplexNDArray& x, bool scaled,
           Array<octave_idx_type>& ierr)
{
  dim_vector dv = x.dims ();
  FloatComplexNDArray retval;

  if (dv != alpha.dims ())
    (*current_liboctave_error_handler)
      ("%s: the sizes of alpha and x must conform", fn);

  octave_idx_type nel = dv.numel ();

  retval.resize (dv);
  ierr.resize (dv);

  for (octave_idx_type i = 0; i < nel; i++)
    retval(i) = f (x(i), alpha(i), (scaled ? 2 : 1), ierr(i));

  return retval;
}

static inline FloatComplexMatrix
do_bessel (fptr f, const char *, const FloatRowVector& alpha,
           const FloatComplexColumnVector& x, bool scaled,
           Array<octave_idx_type>& ierr)
{
  octave_idx_type nr = x.numel ();
  octave_idx_type nc = alpha.numel ();

  FloatComplexMatrix retval (nr, nc);

  ierr.resize (dim_vector (nr, nc));

  for (octave_idx_type j = 0; j < nc; j++)
    for (octave_idx_type i = 0; i < nr; i++)
      retval(i,j) = f (x(i), alpha(j), (scaled ? 2 : 1), ierr(i,j));

  return retval;
}

#define SS_BESSEL(name, fcn) \
  FloatComplex \
  name (float alpha, const FloatComplex& x, bool scaled, octave_idx_type& ierr) \
  { \
    return do_bessel (fcn, #name, alpha, x, scaled, ierr); \
  }

#define SM_BESSEL(name, fcn) \
  FloatComplexMatrix \
  name (float alpha, const FloatComplexMatrix& x, bool scaled, \
        Array<octave_idx_type>& ierr) \
  { \
    return do_bessel (fcn, #name, alpha, x, scaled, ierr); \
  }

#define MS_BESSEL(name, fcn) \
  FloatComplexMatrix \
  name (const FloatMatrix& alpha, const FloatComplex& x, bool scaled, \
        Array<octave_idx_type>& ierr) \
  { \
    return do_bessel (fcn, #name, alpha, x, scaled, ierr); \
  }

#define MM_BESSEL(name, fcn) \
  FloatComplexMatrix \
  name (const FloatMatrix& alpha, const FloatComplexMatrix& x, bool scaled, \
        Array<octave_idx_type>& ierr) \
  { \
    return do_bessel (fcn, #name, alpha, x, scaled, ierr); \
  }

#define SN_BESSEL(name, fcn) \
  FloatComplexNDArray \
  name (float alpha, const FloatComplexNDArray& x, bool scaled, \
        Array<octave_idx_type>& ierr) \
  { \
    return do_bessel (fcn, #name, alpha, x, scaled, ierr); \
  }

#define NS_BESSEL(name, fcn) \
  FloatComplexNDArray \
  name (const FloatNDArray& alpha, const FloatComplex& x, bool scaled, \
        Array<octave_idx_type>& ierr) \
  { \
    return do_bessel (fcn, #name, alpha, x, scaled, ierr); \
  }

#define NN_BESSEL(name, fcn) \
  FloatComplexNDArray \
  name (const FloatNDArray& alpha, const FloatComplexNDArray& x, bool scaled, \
        Array<octave_idx_type>& ierr) \
  { \
    return do_bessel (fcn, #name, alpha, x, scaled, ierr); \
  }

#define RC_BESSEL(name, fcn) \
  FloatComplexMatrix \
  name (const FloatRowVector& alpha, const FloatComplexColumnVector& x, bool scaled, \
        Array<octave_idx_type>& ierr) \
  { \
    return do_bessel (fcn, #name, alpha, x, scaled, ierr); \
  }

#define ALL_BESSEL(name, fcn) \
  SS_BESSEL (name, fcn) \
  SM_BESSEL (name, fcn) \
  MS_BESSEL (name, fcn) \
  MM_BESSEL (name, fcn) \
  SN_BESSEL (name, fcn) \
  NS_BESSEL (name, fcn) \
  NN_BESSEL (name, fcn) \
  RC_BESSEL (name, fcn)

ALL_BESSEL (besselj, cbesj)
ALL_BESSEL (bessely, cbesy)
ALL_BESSEL (besseli, cbesi)
ALL_BESSEL (besselk, cbesk)
ALL_BESSEL (besselh1, cbesh1)
ALL_BESSEL (besselh2, cbesh2)

#undef ALL_BESSEL
#undef SS_BESSEL
#undef SM_BESSEL
#undef MS_BESSEL
#undef MM_BESSEL
#undef SN_BESSEL
#undef NS_BESSEL
#undef NN_BESSEL
#undef RC_BESSEL

Complex
airy (const Complex& z, bool deriv, bool scaled, octave_idx_type& ierr)
{
  double ar = 0.0;
  double ai = 0.0;

  octave_idx_type nz;

  double zr = z.real ();
  double zi = z.imag ();

  octave_idx_type id = deriv ? 1 : 0;

  F77_FUNC (zairy, ZAIRY) (zr, zi, id, 2, ar, ai, nz, ierr);

  if (! scaled)
    {
      Complex expz = exp (- 2.0 / 3.0 * z * sqrt (z));

      double rexpz = real (expz);
      double iexpz = imag (expz);

      double tmp = ar*rexpz - ai*iexpz;

      ai = ar*iexpz + ai*rexpz;
      ar = tmp;
    }

  if (zi == 0.0 && (! scaled || zr >= 0.0))
    ai = 0.0;

  return bessel_return_value (Complex (ar, ai), ierr);
}

Complex
biry (const Complex& z, bool deriv, bool scaled, octave_idx_type& ierr)
{
  double ar = 0.0;
  double ai = 0.0;

  double zr = z.real ();
  double zi = z.imag ();

  octave_idx_type id = deriv ? 1 : 0;

  F77_FUNC (zbiry, ZBIRY) (zr, zi, id, 2, ar, ai, ierr);

  if (! scaled)
    {
      Complex expz = exp (std::abs (real (2.0 / 3.0 * z * sqrt (z))));

      double rexpz = real (expz);
      double iexpz = imag (expz);

      double tmp = ar*rexpz - ai*iexpz;

      ai = ar*iexpz + ai*rexpz;
      ar = tmp;
    }

  if (zi == 0.0 && (! scaled || zr >= 0.0))
    ai = 0.0;

  return bessel_return_value (Complex (ar, ai), ierr);
}

ComplexMatrix
airy (const ComplexMatrix& z, bool deriv, bool scaled,
      Array<octave_idx_type>& ierr)
{
  octave_idx_type nr = z.rows ();
  octave_idx_type nc = z.cols ();

  ComplexMatrix retval (nr, nc);

  ierr.resize (dim_vector (nr, nc));

  for (octave_idx_type j = 0; j < nc; j++)
    for (octave_idx_type i = 0; i < nr; i++)
      retval(i,j) = airy (z(i,j), deriv, scaled, ierr(i,j));

  return retval;
}

ComplexMatrix
biry (const ComplexMatrix& z, bool deriv, bool scaled,
      Array<octave_idx_type>& ierr)
{
  octave_idx_type nr = z.rows ();
  octave_idx_type nc = z.cols ();

  ComplexMatrix retval (nr, nc);

  ierr.resize (dim_vector (nr, nc));

  for (octave_idx_type j = 0; j < nc; j++)
    for (octave_idx_type i = 0; i < nr; i++)
      retval(i,j) = biry (z(i,j), deriv, scaled, ierr(i,j));

  return retval;
}

ComplexNDArray
airy (const ComplexNDArray& z, bool deriv, bool scaled,
      Array<octave_idx_type>& ierr)
{
  dim_vector dv = z.dims ();
  octave_idx_type nel = dv.numel ();
  ComplexNDArray retval (dv);

  ierr.resize (dv);

  for (octave_idx_type i = 0; i < nel; i++)
    retval(i) = airy (z(i), deriv, scaled, ierr(i));

  return retval;
}

ComplexNDArray
biry (const ComplexNDArray& z, bool deriv, bool scaled,
      Array<octave_idx_type>& ierr)
{
  dim_vector dv = z.dims ();
  octave_idx_type nel = dv.numel ();
  ComplexNDArray retval (dv);

  ierr.resize (dv);

  for (octave_idx_type i = 0; i < nel; i++)
    retval(i) = biry (z(i), deriv, scaled, ierr(i));

  return retval;
}

FloatComplex
airy (const FloatComplex& z, bool deriv, bool scaled, octave_idx_type& ierr)
{
  float ar = 0.0;
  float ai = 0.0;

  octave_idx_type nz;

  float zr = z.real ();
  float zi = z.imag ();

  octave_idx_type id = deriv ? 1 : 0;

  F77_FUNC (cairy, CAIRY) (zr, zi, id, 2, ar, ai, nz, ierr);

  if (! scaled)
    {
      FloatComplex expz = exp (- 2.0f / 3.0f * z * sqrt (z));

      float rexpz = real (expz);
      float iexpz = imag (expz);

      float tmp = ar*rexpz - ai*iexpz;

      ai = ar*iexpz + ai*rexpz;
      ar = tmp;
    }

  if (zi == 0.0 && (! scaled || zr >= 0.0))
    ai = 0.0;

  return bessel_return_value (FloatComplex (ar, ai), ierr);
}

FloatComplex
biry (const FloatComplex& z, bool deriv, bool scaled, octave_idx_type& ierr)
{
  float ar = 0.0;
  float ai = 0.0;

  float zr = z.real ();
  float zi = z.imag ();

  octave_idx_type id = deriv ? 1 : 0;

  F77_FUNC (cbiry, CBIRY) (zr, zi, id, 2, ar, ai, ierr);

  if (! scaled)
    {
      FloatComplex expz = exp (std::abs (real (2.0f / 3.0f * z * sqrt (z))));

      float rexpz = real (expz);
      float iexpz = imag (expz);

      float tmp = ar*rexpz - ai*iexpz;

      ai = ar*iexpz + ai*rexpz;
      ar = tmp;
    }

  if (zi == 0.0 && (! scaled || zr >= 0.0))
    ai = 0.0;

  return bessel_return_value (FloatComplex (ar, ai), ierr);
}

FloatComplexMatrix
airy (const FloatComplexMatrix& z, bool deriv, bool scaled,
      Array<octave_idx_type>& ierr)
{
  octave_idx_type nr = z.rows ();
  octave_idx_type nc = z.cols ();

  FloatComplexMatrix retval (nr, nc);

  ierr.resize (dim_vector (nr, nc));

  for (octave_idx_type j = 0; j < nc; j++)
    for (octave_idx_type i = 0; i < nr; i++)
      retval(i,j) = airy (z(i,j), deriv, scaled, ierr(i,j));

  return retval;
}

FloatComplexMatrix
biry (const FloatComplexMatrix& z, bool deriv, bool scaled,
      Array<octave_idx_type>& ierr)
{
  octave_idx_type nr = z.rows ();
  octave_idx_type nc = z.cols ();

  FloatComplexMatrix retval (nr, nc);

  ierr.resize (dim_vector (nr, nc));

  for (octave_idx_type j = 0; j < nc; j++)
    for (octave_idx_type i = 0; i < nr; i++)
      retval(i,j) = biry (z(i,j), deriv, scaled, ierr(i,j));

  return retval;
}

FloatComplexNDArray
airy (const FloatComplexNDArray& z, bool deriv, bool scaled,
      Array<octave_idx_type>& ierr)
{
  dim_vector dv = z.dims ();
  octave_idx_type nel = dv.numel ();
  FloatComplexNDArray retval (dv);

  ierr.resize (dv);

  for (octave_idx_type i = 0; i < nel; i++)
    retval(i) = airy (z(i), deriv, scaled, ierr(i));

  return retval;
}

FloatComplexNDArray
biry (const FloatComplexNDArray& z, bool deriv, bool scaled,
      Array<octave_idx_type>& ierr)
{
  dim_vector dv = z.dims ();
  octave_idx_type nel = dv.numel ();
  FloatComplexNDArray retval (dv);

  ierr.resize (dv);

  for (octave_idx_type i = 0; i < nel; i++)
    retval(i) = biry (z(i), deriv, scaled, ierr(i));

  return retval;
}

OCTAVE_NORETURN static void
err_betainc_nonconformant (const dim_vector& d1, const dim_vector& d2,
                             const dim_vector& d3)
{
  std::string d1_str = d1.str ();
  std::string d2_str = d2.str ();
  std::string d3_str = d3.str ();

  (*current_liboctave_error_handler)
    ("betainc: nonconformant arguments (x is %s, a is %s, b is %s)",
     d1_str.c_str (), d2_str.c_str (), d3_str.c_str ());
}

OCTAVE_NORETURN static void
err_betaincinv_nonconformant (const dim_vector& d1, const dim_vector& d2,
                                const dim_vector& d3)
{
  std::string d1_str = d1.str ();
  std::string d2_str = d2.str ();
  std::string d3_str = d3.str ();

  (*current_liboctave_error_handler)
    ("betaincinv: nonconformant arguments (x is %s, a is %s, b is %s)",
     d1_str.c_str (), d2_str.c_str (), d3_str.c_str ());
}

double
betainc (double x, double a, double b)
{
  double retval;
  F77_XFCN (xdbetai, XDBETAI, (x, a, b, retval));
  return retval;
}

Array<double>
betainc (double x, double a, const Array<double>& b)
{
  dim_vector dv = b.dims ();
  octave_idx_type nel = dv.numel ();

  Array<double> retval (dv);

  double *pretval = retval.fortran_vec ();

  for (octave_idx_type i = 0; i < nel; i++)
    *pretval++ = betainc (x, a, b(i));

  return retval;
}

Array<double>
betainc (double x, const Array<double>& a, double b)
{
  dim_vector dv = a.dims ();
  octave_idx_type nel = dv.numel ();

  Array<double> retval (dv);

  double *pretval = retval.fortran_vec ();

  for (octave_idx_type i = 0; i < nel; i++)
    *pretval++ = betainc (x, a(i), b);

  return retval;
}

Array<double>
betainc (double x, const Array<double>& a, const Array<double>& b)
{
  Array<double> retval;
  dim_vector dv = a.dims ();

  if (dv != b.dims ())
    err_betainc_nonconformant (dim_vector (0, 0), dv, b.dims ());

  octave_idx_type nel = dv.numel ();

  retval.resize (dv);

  double *pretval = retval.fortran_vec ();

  for (octave_idx_type i = 0; i < nel; i++)
    *pretval++ = betainc (x, a(i), b(i));

  return retval;
}

Array<double>
betainc (const Array<double>& x, double a, double b)
{
  dim_vector dv = x.dims ();
  octave_idx_type nel = dv.numel ();

  Array<double> retval (dv);

  double *pretval = retval.fortran_vec ();

  for (octave_idx_type i = 0; i < nel; i++)
    *pretval++ = betainc (x(i), a, b);

  return retval;
}

Array<double>
betainc (const Array<double>& x, double a, const Array<double>& b)
{
  Array<double> retval;
  dim_vector dv = x.dims ();

  if (dv != b.dims ())
    err_betainc_nonconformant (dv, dim_vector (0, 0), b.dims ());

  octave_idx_type nel = dv.numel ();

  retval.resize (dv);

  double *pretval = retval.fortran_vec ();

  for (octave_idx_type i = 0; i < nel; i++)
    *pretval++ = betainc (x(i), a, b(i));

  return retval;
}

Array<double>
betainc (const Array<double>& x, const Array<double>& a, double b)
{
  Array<double> retval;
  dim_vector dv = x.dims ();

  if (dv != a.dims ())
    err_betainc_nonconformant (dv, a.dims (), dim_vector (0, 0));

  octave_idx_type nel = dv.numel ();

  retval.resize (dv);

  double *pretval = retval.fortran_vec ();

  for (octave_idx_type i = 0; i < nel; i++)
    *pretval++ = betainc (x(i), a(i), b);

  return retval;
}

Array<double>
betainc (const Array<double>& x, const Array<double>& a, const Array<double>& b)
{
  Array<double> retval;
  dim_vector dv = x.dims ();

  if (dv != a.dims () || dv != b.dims ())
    err_betainc_nonconformant (dv, a.dims (), b.dims ());

  octave_idx_type nel = dv.numel ();

  retval.resize (dv);

  double *pretval = retval.fortran_vec ();

  for (octave_idx_type i = 0; i < nel; i++)
    *pretval++ = betainc (x(i), a(i), b(i));

  return retval;
}

float
betainc (float x, float a, float b)
{
  float retval;
  F77_XFCN (xbetai, XBETAI, (x, a, b, retval));
  return retval;
}

Array<float>
betainc (float x, float a, const Array<float>& b)
{
  dim_vector dv = b.dims ();
  octave_idx_type nel = dv.numel ();

  Array<float> retval (dv);

  float *pretval = retval.fortran_vec ();

  for (octave_idx_type i = 0; i < nel; i++)
    *pretval++ = betainc (x, a, b(i));

  return retval;
}

Array<float>
betainc (float x, const Array<float>& a, float b)
{
  dim_vector dv = a.dims ();
  octave_idx_type nel = dv.numel ();

  Array<float> retval (dv);

  float *pretval = retval.fortran_vec ();

  for (octave_idx_type i = 0; i < nel; i++)
    *pretval++ = betainc (x, a(i), b);

  return retval;
}

Array<float>
betainc (float x, const Array<float>& a, const Array<float>& b)
{
  Array<float> retval;
  dim_vector dv = a.dims ();

  if (dv != b.dims ())
    err_betainc_nonconformant (dim_vector (0, 0), dv, b.dims ());

  octave_idx_type nel = dv.numel ();

  retval.resize (dv);

  float *pretval = retval.fortran_vec ();

  for (octave_idx_type i = 0; i < nel; i++)
    *pretval++ = betainc (x, a(i), b(i));

  return retval;
}

Array<float>
betainc (const Array<float>& x, float a, float b)
{
  dim_vector dv = x.dims ();
  octave_idx_type nel = dv.numel ();

  Array<float> retval (dv);

  float *pretval = retval.fortran_vec ();

  for (octave_idx_type i = 0; i < nel; i++)
    *pretval++ = betainc (x(i), a, b);

  return retval;
}

Array<float>
betainc (const Array<float>& x, float a, const Array<float>& b)
{
  Array<float> retval;
  dim_vector dv = x.dims ();

  if (dv != b.dims ())
    err_betainc_nonconformant (dv, dim_vector (0, 0), b.dims ());

  octave_idx_type nel = dv.numel ();

  retval.resize (dv);

  float *pretval = retval.fortran_vec ();

  for (octave_idx_type i = 0; i < nel; i++)
    *pretval++ = betainc (x(i), a, b(i));

  return retval;
}

Array<float>
betainc (const Array<float>& x, const Array<float>& a, float b)
{
  Array<float> retval;
  dim_vector dv = x.dims ();

  if (dv != a.dims ())
    err_betainc_nonconformant (dv, a.dims (), dim_vector (0, 0));

  octave_idx_type nel = dv.numel ();

  retval.resize (dv);

  float *pretval = retval.fortran_vec ();

  for (octave_idx_type i = 0; i < nel; i++)
    *pretval++ = betainc (x(i), a(i), b);

  return retval;
}

Array<float>
betainc (const Array<float>& x, const Array<float>& a, const Array<float>& b)
{
  Array<float> retval;
  dim_vector dv = x.dims ();

  if (dv != a.dims () || dv != b.dims ())
    err_betainc_nonconformant (dv, a.dims (), b.dims ());

  octave_idx_type nel = dv.numel ();

  retval.resize (dv);

  float *pretval = retval.fortran_vec ();

  for (octave_idx_type i = 0; i < nel; i++)
    *pretval++ = betainc (x(i), a(i), b(i));

  return retval;
}

// FIXME: there is still room for improvement here...

double
gammainc (double x, double a, bool& err)
{
  if (a < 0.0 || x < 0.0)
    (*current_liboctave_error_handler)
      ("gammainc: A and X must be non-negative");

  err = false;

  double retval;

  F77_XFCN (xgammainc, XGAMMAINC, (a, x, retval));

  return retval;
}

Matrix
gammainc (double x, const Matrix& a)
{
  octave_idx_type nr = a.rows ();
  octave_idx_type nc = a.cols ();

  Matrix retval (nr, nc);

  bool err;

  for (octave_idx_type j = 0; j < nc; j++)
    for (octave_idx_type i = 0; i < nr; i++)
      {
        retval(i,j) = gammainc (x, a(i,j), err);

        if (err)
          return Matrix ();
      }

  return retval;
}

Matrix
gammainc (const Matrix& x, double a)
{
  octave_idx_type nr = x.rows ();
  octave_idx_type nc = x.cols ();

  Matrix retval (nr, nc);

  bool err;

  for (octave_idx_type j = 0; j < nc; j++)
    for (octave_idx_type i = 0; i < nr; i++)
      {
        retval(i,j) = gammainc (x(i,j), a, err);

        if (err)
          return Matrix ();
      }

  return retval;
}

Matrix
gammainc (const Matrix& x, const Matrix& a)
{
  octave_idx_type nr = x.rows ();
  octave_idx_type nc = x.cols ();

  octave_idx_type a_nr = a.rows ();
  octave_idx_type a_nc = a.cols ();

  if (nr != a_nr || nc != a_nc)
    (*current_liboctave_error_handler)
      ("gammainc: nonconformant arguments (arg 1 is %dx%d, arg 2 is %dx%d)",
       nr, nc, a_nr, a_nc);

  Matrix retval (nr, nc);

  bool err;

  for (octave_idx_type j = 0; j < nc; j++)
    for (octave_idx_type i = 0; i < nr; i++)
      {
        retval(i,j) = gammainc (x(i,j), a(i,j), err);

        if (err)
          return Matrix ();
      }

  return retval;
}

NDArray
gammainc (double x, const NDArray& a)
{
  dim_vector dv = a.dims ();
  octave_idx_type nel = dv.numel ();

  NDArray retval (dv);

  bool err;

  for (octave_idx_type i = 0; i < nel; i++)
    {
      retval(i) = gammainc (x, a(i), err);

      if (err)
        return NDArray ();
    }

  return retval;
}

NDArray
gammainc (const NDArray& x, double a)
{
  dim_vector dv = x.dims ();
  octave_idx_type nel = dv.numel ();

  NDArray retval (dv);

  bool err;

  for (octave_idx_type i = 0; i < nel; i++)
    {
      retval(i) = gammainc (x(i), a, err);

      if (err)
        return NDArray ();
    }

  return retval;
}

NDArray
gammainc (const NDArray& x, const NDArray& a)
{
  dim_vector dv = x.dims ();
  octave_idx_type nel = dv.numel ();

  if (dv != a.dims ())
    {
      std::string x_str = dv.str ();
      std::string a_str = a.dims ().str ();

      (*current_liboctave_error_handler)
        ("gammainc: nonconformant arguments (arg 1 is %s, arg 2 is %s)",
         x_str.c_str (), a_str. c_str ());
    }

  NDArray retval (dv);

  bool err;

  for (octave_idx_type i = 0; i < nel; i++)
    {
      retval(i) = gammainc (x(i), a(i), err);

      if (err)
        return NDArray ();
    }

  return retval;
}

float
gammainc (float x, float a, bool& err)
{
  if (a < 0.0 || x < 0.0)
    (*current_liboctave_error_handler)
      ("gammainc: A and X must be non-negative");

  err = false;

  float retval;

  F77_XFCN (xsgammainc, XSGAMMAINC, (a, x, retval));

  return retval;
}

FloatMatrix
gammainc (float x, const FloatMatrix& a)
{
  octave_idx_type nr = a.rows ();
  octave_idx_type nc = a.cols ();

  FloatMatrix retval (nr,  nc);

  bool err;

  for (octave_idx_type j = 0; j < nc; j++)
    for (octave_idx_type i = 0; i < nr; i++)
      {
        retval(i,j) = gammainc (x, a(i,j), err);

        if (err)
          return FloatMatrix ();
      }

  return retval;
}

FloatMatrix
gammainc (const FloatMatrix& x, float a)
{
  octave_idx_type nr = x.rows ();
  octave_idx_type nc = x.cols ();

  FloatMatrix retval (nr, nc);

  bool err;

  for (octave_idx_type j = 0; j < nc; j++)
    for (octave_idx_type i = 0; i < nr; i++)
      {
        retval(i,j) = gammainc (x(i,j), a, err);

        if (err)
          return FloatMatrix ();
      }

  return retval;
}

FloatMatrix
gammainc (const FloatMatrix& x, const FloatMatrix& a)
{
  octave_idx_type nr = x.rows ();
  octave_idx_type nc = x.cols ();

  octave_idx_type a_nr = a.rows ();
  octave_idx_type a_nc = a.cols ();

  if (nr != a_nr || nc != a_nc)
    (*current_liboctave_error_handler)
      ("gammainc: nonconformant arguments (arg 1 is %dx%d, arg 2 is %dx%d)",
       nr, nc, a_nr, a_nc);

  FloatMatrix retval (nr, nc);

  bool err;

  for (octave_idx_type j = 0; j < nc; j++)
    for (octave_idx_type i = 0; i < nr; i++)
      {
        retval(i,j) = gammainc (x(i,j), a(i,j), err);

        if (err)
          return FloatMatrix ();
      }

  return retval;
}

FloatNDArray
gammainc (float x, const FloatNDArray& a)
{
  dim_vector dv = a.dims ();
  octave_idx_type nel = dv.numel ();

  FloatNDArray retval (dv);

  bool err;

  for (octave_idx_type i = 0; i < nel; i++)
    {
      retval(i) = gammainc (x, a(i), err);

      if (err)
        return FloatNDArray ();
    }

  return retval;
}

FloatNDArray
gammainc (const FloatNDArray& x, float a)
{
  dim_vector dv = x.dims ();
  octave_idx_type nel = dv.numel ();

  FloatNDArray retval (dv);

  bool err;

  for (octave_idx_type i = 0; i < nel; i++)
    {
      retval(i) = gammainc (x(i), a, err);

      if (err)
        return FloatNDArray ();
    }

  return retval;
}

FloatNDArray
gammainc (const FloatNDArray& x, const FloatNDArray& a)
{
  dim_vector dv = x.dims ();
  octave_idx_type nel = dv.numel ();

  if (dv != a.dims ())
    {
      std::string x_str = dv.str ();
      std::string a_str = a.dims ().str ();

      (*current_liboctave_error_handler)
        ("gammainc: nonconformant arguments (arg 1 is %s, arg 2 is %s)",
         x_str.c_str (), a_str.c_str ());
    }

  FloatNDArray retval (dv);

  bool err;

  for (octave_idx_type i = 0; i < nel; i++)
    {
      retval(i) = gammainc (x(i), a(i), err);

      if (err)
        return FloatNDArray ();
    }

  return retval;
}


Complex rc_log1p (double x)
{
  const double pi = 3.14159265358979323846;
  return (x < -1.0
          ? Complex (gnulib::log (-(1.0 + x)), pi)
          : Complex (xlog1p (x)));
}

FloatComplex rc_log1p (float x)
{
  const float pi = 3.14159265358979323846f;
  return (x < -1.0f
          ? FloatComplex (gnulib::logf (-(1.0f + x)), pi)
          : FloatComplex (xlog1p (x)));
}

// This algorithm is due to P. J. Acklam.
//
// See http://home.online.no/~pjacklam/notes/invnorm/
//
// The rational approximation has relative accuracy 1.15e-9 in the whole
// region.  For doubles, it is refined by a single step of Halley's 3rd
// order method.  For single precision, the accuracy is already OK, so
// we skip it to get faster evaluation.

static double do_erfinv (double x, bool refine)
{
  // Coefficients of rational approximation.
  static const double a[] =
  {
    -2.806989788730439e+01,  1.562324844726888e+02,
    -1.951109208597547e+02,  9.783370457507161e+01,
    -2.168328665628878e+01,  1.772453852905383e+00
  };
  static const double b[] =
  {
    -5.447609879822406e+01,  1.615858368580409e+02,
    -1.556989798598866e+02,  6.680131188771972e+01,
    -1.328068155288572e+01
  };
  static const double c[] =
  {
    -5.504751339936943e-03, -2.279687217114118e-01,
    -1.697592457770869e+00, -1.802933168781950e+00,
    3.093354679843505e+00,  2.077595676404383e+00
  };
  static const double d[] =
  {
    7.784695709041462e-03,  3.224671290700398e-01,
    2.445134137142996e+00,  3.754408661907416e+00
  };

  static const double spi2 = 8.862269254527579e-01; // sqrt(pi)/2.
  static const double pbreak = 0.95150;
  double ax = fabs (x), y;

  // Select case.
  if (ax <= pbreak)
    {
      // Middle region.
      const double q = 0.5 * x, r = q*q;
      const double yn = (((((a[0]*r + a[1])*r + a[2])*r + a[3])*r + a[4])*r + a[5])*q;
      const double yd = ((((b[0]*r + b[1])*r + b[2])*r + b[3])*r + b[4])*r + 1.0;
      y = yn / yd;
    }
  else if (ax < 1.0)
    {
      // Tail region.
      const double q = sqrt (-2*gnulib::log (0.5*(1-ax)));
      const double yn = ((((c[0]*q + c[1])*q + c[2])*q + c[3])*q + c[4])*q + c[5];
      const double yd = (((d[0]*q + d[1])*q + d[2])*q + d[3])*q + 1.0;
      y = yn / yd * signum (-x);
    }
  else if (ax == 1.0)
    return octave_Inf * signum (x);
  else
    return octave_NaN;

  if (refine)
    {
      // One iteration of Halley's method gives full precision.
      double u = (erf (y) - x) * spi2 * exp (y*y);
      y -= u / (1 + y*u);
    }

  return y;
}

double erfinv (double x)
{
  return do_erfinv (x, true);
}

float erfinv (float x)
{
  return do_erfinv (x, false);
}

// The algorthim for erfcinv is an adaptation of the erfinv algorithm
// above from P. J. Acklam.  It has been modified to run over the
// different input domain of erfcinv.  See the notes for erfinv for an
// explanation.

static double do_erfcinv (double x, bool refine)
{
  // Coefficients of rational approximation.
  static const double a[] =
  {
    -2.806989788730439e+01,  1.562324844726888e+02,
    -1.951109208597547e+02,  9.783370457507161e+01,
    -2.168328665628878e+01,  1.772453852905383e+00
  };
  static const double b[] =
  {
    -5.447609879822406e+01,  1.615858368580409e+02,
    -1.556989798598866e+02,  6.680131188771972e+01,
    -1.328068155288572e+01
  };
  static const double c[] =
  {
    -5.504751339936943e-03, -2.279687217114118e-01,
    -1.697592457770869e+00, -1.802933168781950e+00,
    3.093354679843505e+00,  2.077595676404383e+00
  };
  static const double d[] =
  {
    7.784695709041462e-03,  3.224671290700398e-01,
    2.445134137142996e+00,  3.754408661907416e+00
  };

  static const double spi2 = 8.862269254527579e-01; // sqrt(pi)/2.
  static const double pbreak_lo = 0.04850;  // 1-pbreak
  static const double pbreak_hi = 1.95150;  // 1+pbreak
  double y;

  // Select case.
  if (x >= pbreak_lo && x <= pbreak_hi)
    {
      // Middle region.
      const double q = 0.5*(1-x), r = q*q;
      const double yn = (((((a[0]*r + a[1])*r + a[2])*r + a[3])*r + a[4])*r + a[5])*q;
      const double yd = ((((b[0]*r + b[1])*r + b[2])*r + b[3])*r + b[4])*r + 1.0;
      y = yn / yd;
    }
  else if (x > 0.0 && x < 2.0)
    {
      // Tail region.
      const double q = (x < 1
                        ? sqrt (-2*gnulib::log (0.5*x))
                        : sqrt (-2*gnulib::log (0.5*(2-x))));

      const double yn = ((((c[0]*q + c[1])*q + c[2])*q + c[3])*q + c[4])*q + c[5];

      const double yd = (((d[0]*q + d[1])*q + d[2])*q + d[3])*q + 1.0;

      y = yn / yd;

      if (x < pbreak_lo)
        y = -y;
    }
  else if (x == 0.0)
    return octave_Inf;
  else if (x == 2.0)
    return -octave_Inf;
  else
    return octave_NaN;

  if (refine)
    {
      // One iteration of Halley's method gives full precision.
      double u = (erf (y) - (1-x)) * spi2 * exp (y*y);
      y -= u / (1 + y*u);
    }

  return y;
}

double erfcinv (double x)
{
  return do_erfcinv (x, true);
}

float erfcinv (float x)
{
  return do_erfcinv (x, false);
}

//
//  Incomplete Beta function ratio
//
//  Algorithm based on the one by John Burkardt.
//  See http://people.sc.fsu.edu/~jburkardt/cpp_src/asa109/asa109.html
//
//  The original code is distributed under the GNU LGPL v3 license.
//
//  Reference:
//
//    KL Majumder, GP Bhattacharjee,
//    Algorithm AS 63:
//    The incomplete Beta Integral,
//    Applied Statistics,
//    Volume 22, Number 3, 1973, pages 409-411.
//
double
betain (double x, double p, double q, double beta, bool& err)
{
  double acu = 0.1E-14, ai, cx;
  bool indx;
  int ns;
  double pp, psq, qq, rx, temp, term, value, xx;

  value = x;
  err = false;

  //  Check the input arguments.

  if ((p <= 0.0 || q <= 0.0) || (x < 0.0 || 1.0 < x))
    {
      err = true;
      return value;
    }

  //  Special cases.

  if (x == 0.0 || x == 1.0)
    {
      return value;
    }

  //  Change tail if necessary and determine S.

  psq = p + q;
  cx = 1.0 - x;

  if (p < psq * x)
    {
      xx = cx;
      cx = x;
      pp = q;
      qq = p;
      indx = true;
    }
  else
    {
      xx = x;
      pp = p;
      qq = q;
      indx = false;
    }

  term = 1.0;
  ai = 1.0;
  value = 1.0;
  ns = static_cast<int> (qq + cx * psq);

  //  Use the Soper reduction formula.

  rx = xx / cx;
  temp = qq - ai;
  if (ns == 0)
    {
      rx = xx;
    }

  for ( ; ; )
    {
      term *= temp * rx / (pp + ai);
      value += term;
      temp = fabs (term);

      if (temp <= acu && temp <= acu * value)
        {
          value *= exp (pp * gnulib::log (xx)
                        + (qq - 1.0) * gnulib::log (cx) - beta) / pp;

          if (indx)
            {
              value = 1.0 - value;
            }
          break;
        }

      ai += 1.0;
      ns -= 1;

      if (0 <= ns)
        {
          temp = qq - ai;
          if (ns == 0)
            {
              rx = xx;
            }
        }
      else
        {
          temp = psq;
          psq += 1.0;
        }
    }

  return value;
}

//
//  Inverse of the incomplete Beta function
//
//  Algorithm based on the one by John Burkardt.
//  See http://people.sc.fsu.edu/~jburkardt/cpp_src/asa109/asa109.html
//
//  The original code is distributed under the GNU LGPL v3 license.
//
//  Reference:
//
//    GW Cran, KJ Martin, GE Thomas,
//    Remark AS R19 and Algorithm AS 109:
//    A Remark on Algorithms AS 63: The Incomplete Beta Integral
//    and AS 64: Inverse of the Incomplete Beta Integeral,
//    Applied Statistics,
//    Volume 26, Number 1, 1977, pages 111-114.
//
double
betaincinv (double y, double p, double q)
{
  double a, acu, adj, fpu, g, h;
  int iex;
  bool indx;
  double pp, prev, qq, r, s, sae = -37.0, sq, t, tx, value, w, xin, ycur, yprev;

  double beta = xlgamma (p) + xlgamma (q) - xlgamma (p + q);
  bool err = false;
  fpu = pow (10.0, sae);
  value = y;

  //  Test for admissibility of parameters.

  if (p <= 0.0 || q <= 0.0)
    (*current_liboctave_error_handler) ("betaincinv: wrong parameters");
  if (y < 0.0 || 1.0 < y)
    (*current_liboctave_error_handler) ("betaincinv: wrong parameter Y");

  if (y == 0.0 || y == 1.0)
    return value;

  //  Change tail if necessary.

  if (0.5 < y)
    {
      a = 1.0 - y;
      pp = q;
      qq = p;
      indx = true;
    }
  else
    {
      a = y;
      pp = p;
      qq = q;
      indx = false;
    }

  //  Calculate the initial approximation.

  r = sqrt (- gnulib::log (a * a));

  ycur = r - (2.30753 + 0.27061 * r) / (1.0 + (0.99229 + 0.04481 * r) * r);

  if (1.0 < pp && 1.0 < qq)
    {
      r = (ycur * ycur - 3.0) / 6.0;
      s = 1.0 / (pp + pp - 1.0);
      t = 1.0 / (qq + qq - 1.0);
      h = 2.0 / (s + t);
      w = ycur * sqrt (h + r) / h - (t - s) * (r + 5.0 / 6.0 - 2.0 / (3.0 * h));
      value = pp / (pp + qq * exp (w + w));
    }
  else
    {
      r = qq + qq;
      t = 1.0 / (9.0 * qq);
      t = r * pow (1.0 - t + ycur * sqrt (t), 3);

      if (t <= 0.0)
        {
          value = 1.0 - exp ((gnulib::log ((1.0 - a) * qq) + beta) / qq);
        }
      else
        {
          t = (4.0 * pp + r - 2.0) / t;

          if (t <= 1.0)
            {
              value = exp ((gnulib::log (a * pp) + beta) / pp);
            }
          else
            {
              value = 1.0 - 2.0 / (t + 1.0);
            }
        }
    }

  //  Solve for X by a modified Newton-Raphson method,
  //  using the function BETAIN.

  r = 1.0 - pp;
  t = 1.0 - qq;
  yprev = 0.0;
  sq = 1.0;
  prev = 1.0;

  if (value < 0.0001)
    {
      value = 0.0001;
    }

  if (0.9999 < value)
    {
      value = 0.9999;
    }

  iex = std::max (- 5.0 / pp / pp - 1.0 / pow (a, 0.2) - 13.0, sae);

  acu = pow (10.0, iex);

  for ( ; ; )
    {
      ycur = betain (value, pp, qq, beta, err);

      if (err)
        {
          return value;
        }

      xin = value;
      ycur = (ycur - a) * exp (beta + r * gnulib::log (xin)
                               + t * gnulib::log (1.0 - xin));

      if (ycur * yprev <= 0.0)
        {
          prev = std::max (sq, fpu);
        }

      g = 1.0;

      for ( ; ; )
        {
          for ( ; ; )
            {
              adj = g * ycur;
              sq = adj * adj;

              if (sq < prev)
                {
                  tx = value - adj;

                  if (0.0 <= tx && tx <= 1.0)
                    {
                      break;
                    }
                }
              g /= 3.0;
            }

          if (prev <= acu)
            {
              if (indx)
                {
                  value = 1.0 - value;
                }
              return value;
            }

          if (ycur * ycur <= acu)
            {
              if (indx)
                {
                  value = 1.0 - value;
                }
              return value;
            }

          if (tx != 0.0 && tx != 1.0)
            {
              break;
            }

          g /= 3.0;
        }

      if (tx == value)
        {
          break;
        }

      value = tx;
      yprev = ycur;
    }

  if (indx)
    {
      value = 1.0 - value;
    }

  return value;
}

Array<double>
betaincinv (double x, double a, const Array<double>& b)
{
  dim_vector dv = b.dims ();
  octave_idx_type nel = dv.numel ();

  Array<double> retval (dv);

  double *pretval = retval.fortran_vec ();

  for (octave_idx_type i = 0; i < nel; i++)
    *pretval++ = betaincinv (x, a, b(i));

  return retval;
}

Array<double>
betaincinv (double x, const Array<double>& a, double b)
{
  dim_vector dv = a.dims ();
  octave_idx_type nel = dv.numel ();

  Array<double> retval (dv);

  double *pretval = retval.fortran_vec ();

  for (octave_idx_type i = 0; i < nel; i++)
    *pretval++ = betaincinv (x, a(i), b);

  return retval;
}

Array<double>
betaincinv (double x, const Array<double>& a, const Array<double>& b)
{
  Array<double> retval;
  dim_vector dv = a.dims ();

  if (dv != b.dims ())
    err_betaincinv_nonconformant (dim_vector (0, 0), dv, b.dims ());

  octave_idx_type nel = dv.numel ();

  retval.resize (dv);

  double *pretval = retval.fortran_vec ();

  for (octave_idx_type i = 0; i < nel; i++)
    *pretval++ = betaincinv (x, a(i), b(i));

  return retval;
}

Array<double>
betaincinv (const Array<double>& x, double a, double b)
{
  dim_vector dv = x.dims ();
  octave_idx_type nel = dv.numel ();

  Array<double> retval (dv);

  double *pretval = retval.fortran_vec ();

  for (octave_idx_type i = 0; i < nel; i++)
    *pretval++ = betaincinv (x(i), a, b);

  return retval;
}

Array<double>
betaincinv (const Array<double>& x, double a, const Array<double>& b)
{
  Array<double> retval;
  dim_vector dv = x.dims ();

  if (dv != b.dims ())
    err_betaincinv_nonconformant (dv, dim_vector (0, 0), b.dims ());

  octave_idx_type nel = dv.numel ();

  retval.resize (dv);

  double *pretval = retval.fortran_vec ();

  for (octave_idx_type i = 0; i < nel; i++)
    *pretval++ = betaincinv (x(i), a, b(i));

  return retval;
}

Array<double>
betaincinv (const Array<double>& x, const Array<double>& a, double b)
{
  Array<double> retval;
  dim_vector dv = x.dims ();

  if (dv != a.dims ())
    err_betaincinv_nonconformant (dv, a.dims (), dim_vector (0, 0));

  octave_idx_type nel = dv.numel ();

  retval.resize (dv);

  double *pretval = retval.fortran_vec ();

  for (octave_idx_type i = 0; i < nel; i++)
    *pretval++ = betaincinv (x(i), a(i), b);

  return retval;
}

Array<double>
betaincinv (const Array<double>& x, const Array<double>& a,
            const Array<double>& b)
{
  Array<double> retval;
  dim_vector dv = x.dims ();

  if (dv != a.dims () && dv != b.dims ())
    err_betaincinv_nonconformant (dv, a.dims (), b.dims ());

  octave_idx_type nel = dv.numel ();

  retval.resize (dv);

  double *pretval = retval.fortran_vec ();

  for (octave_idx_type i = 0; i < nel; i++)
    *pretval++ = betaincinv (x(i), a(i), b(i));

  return retval;
}

void
ellipj (double u, double m, double& sn, double& cn, double& dn, double& err)
{
  static const int Nmax = 16;
  double m1, t=0, si_u, co_u, se_u, ta_u, b, c[Nmax], a[Nmax], phi;
  int n, Nn, ii;

  if (m < 0 || m > 1)
    {
      (*current_liboctave_warning_with_id_handler)
        ("Octave:ellipj-invalid-m", "ellipj: invalid M value, required value 0 <= M <= 1");

      sn = cn = dn = lo_ieee_nan_value ();

      return;
    }

  double sqrt_eps = sqrt (std::numeric_limits<double>::epsilon ());
  if (m < sqrt_eps)
    {
      // For small m, (Abramowitz and Stegun, Section 16.13)
      si_u = sin (u);
      co_u = cos (u);
      t = 0.25*m*(u - si_u*co_u);
      sn = si_u - t * co_u;
      cn = co_u + t * si_u;
      dn = 1 - 0.5*m*si_u*si_u;
    }
  else if ((1 - m) < sqrt_eps)
    {
      // For m1 = (1-m) small (Abramowitz and Stegun, Section 16.15)
      m1 = 1 - m;
      si_u = sinh (u);
      co_u = cosh (u);
      ta_u = tanh (u);
      se_u = 1/co_u;
      sn = ta_u + 0.25*m1*(si_u*co_u - u)*se_u*se_u;
      cn = se_u - 0.25*m1*(si_u*co_u - u)*ta_u*se_u;
      dn = se_u + 0.25*m1*(si_u*co_u + u)*ta_u*se_u;
    }
  else
    {
      // Arithmetic-Geometric Mean (AGM) algorithm
      //   (Abramowitz and Stegun, Section 16.4)
      a[0] = 1;
      b    = sqrt (1 - m);
      c[0] = sqrt (m);
      for (n = 1; n < Nmax; ++n)
        {
          a[n] = (a[n - 1] + b)/2;
          c[n] = (a[n - 1] - b)/2;
          b = sqrt (a[n - 1]*b);
          if (c[n]/a[n] < std::numeric_limits<double>::epsilon ()) break;
        }
      if (n >= Nmax - 1)
        {
          err = 1;
          return;
        }
      Nn = n;
      for (ii = 1; n > 0; ii = ii*2, --n) ; // ii = pow(2,Nn)
      phi = ii*a[Nn]*u;
      for (n = Nn; n > 0; --n)
        {
          phi = (asin ((c[n]/a[n])* sin (phi)) + phi)/2;
        }
      sn = sin (phi);
      cn = cos (phi);
      dn = sqrt (1 - m*sn*sn);
    }
}

void
ellipj (const Complex& u, double m, Complex& sn, Complex& cn, Complex& dn,
        double& err)
{
  double m1 = 1 - m, ss1, cc1, dd1;

  ellipj (imag (u), m1, ss1, cc1, dd1, err);
  if (real (u) == 0)
    {
      // u is pure imag: Jacoby imag. transf.
      sn = Complex (0, ss1/cc1);
      cn = 1/cc1;         //    cn.imag = 0;
      dn = dd1/cc1;       //    dn.imag = 0;
    }
  else
    {
      // u is generic complex
      double ss, cc, dd, ddd;

      ellipj (real (u), m, ss, cc, dd, err);
      ddd = cc1*cc1 + m*ss*ss*ss1*ss1;
      sn = Complex (ss*dd1/ddd, cc*dd*ss1*cc1/ddd);
      cn = Complex (cc*cc1/ddd, -ss*dd*ss1*dd1/ddd);
      dn = Complex (dd*cc1*dd1/ddd, -m*ss*cc*ss1/ddd);
    }
}

static const double pi = 3.14159265358979323846;

template <typename T>
static inline T
xlog (const T& x)
{
  return log (x);
}

template <>
inline double
xlog (const double& x)
{
  return gnulib::log (x);
}

template <>
inline float
xlog (const float& x)
{
  return gnulib::logf (x);
}

template <typename T>
static T
Lanczos_approximation_psi (const T zc)
{
  // Coefficients for C.Lanczos expansion of psi function from XLiFE++
  // gammaFunctions psi_coef[k] = - (2k+1) * lg_coef[k] (see melina++
  // gamma functions -1/12, 3/360,-5/1260, 7/1680,-9/1188,
  // 11*691/360360,-13/156, 15*3617/122400, ? , ?
  static const T dg_coeff[10] = {
    -0.83333333333333333e-1, 0.83333333333333333e-2,
    -0.39682539682539683e-2, 0.41666666666666667e-2,
    -0.75757575757575758e-2, 0.21092796092796093e-1,
    -0.83333333333333333e-1, 0.4432598039215686,
    -0.3053954330270122e+1,  0.125318899521531e+2
  };

  T overz2  = T (1.0) / (zc * zc);
  T overz2k = overz2;

  T p = 0;
  for (octave_idx_type k = 0; k < 10; k++, overz2k *= overz2)
    p += dg_coeff[k] * overz2k;
  p += xlog (zc) - T (0.5) / zc;
  return p;
}

template <typename T>
T
psi (const T& z)
{
  static const double euler_mascheroni = 0.577215664901532860606512090082402431042;

  const bool is_int = (xfloor (z) == z);

  T p = 0;
  if (z <= 0)
    {
      // limits - zeros of the gamma function
      if (is_int)
        p = -octave_Inf; // Matlab returns -Inf for psi (0)
      else
        // Abramowitz and Stegun, page 259, eq 6.3.7
        p = psi (1 - z) - (pi / tan (pi * z));
    }
  else if (is_int)
    {
      // Abramowitz and Stegun, page 258, eq 6.3.2
      p = - euler_mascheroni;
      for (octave_idx_type k = z - 1; k > 0; k--)
        p += 1.0 / k;
    }
  else if (xfloor (z + 0.5) == z + 0.5)
    {
      // Abramowitz and Stegun, page 258, eq 6.3.3 and 6.3.4
      for (octave_idx_type k = z; k > 0; k--)
        p += 1.0 / (2 * k - 1);

      p = - euler_mascheroni - 2 * log (2) + 2 * (p);
    }
  else
    {
      // adapted from XLiFE++ gammaFunctions

      T zc = z;
      // Use formula for derivative of LogGamma(z)
      if (z < 10)
        {
          const signed char n = 10 - z;
          for (signed char k = n - 1; k >= 0; k--)
            p -= 1.0 / (k + z);
          zc += n;
        }
      p += Lanczos_approximation_psi (zc);
    }

  return p;
}

// explicit instantiations
template double psi<double> (const double& z);
template float  psi<float> (const float& z);

template <typename T>
std::complex<T>
psi (const std::complex<T>& z)
{
  // adapted from XLiFE++ gammaFunctions

  typedef typename std::complex<T>::value_type P;

  P z_r  = z.real ();
  P z_ra = z_r;

  std::complex<T> dgam (0.0, 0.0);
  if (z.imag () == 0)
    dgam = std::complex<T> (psi (z_r), 0.0);
  else if (z_r < 0)
    dgam = psi (P (1.0) - z)- (P (pi) / tan (P (pi) * z));
  else
    {
      // Use formula for derivative of LogGamma(z)
      std::complex<T> z_m = z;
      if (z_ra < 8)
        {
          unsigned char n = 8 - z_ra;
          z_m = z + std::complex<T> (n, 0.0);

          // Recurrence formula.  For | Re(z) | < 8, use recursively
          //
          //   DiGamma(z) = DiGamma(z+1) - 1/z
          std::complex<T> z_p = z + P (n - 1);
          for (unsigned char k = n; k > 0; k--, z_p -= 1.0)
            dgam -= P (1.0) / z_p;
        }

      // for | Re(z) | > 8, use derivative of C.Lanczos expansion for
      // LogGamma
      //
      //   psi(z) = log(z) - 1/(2z) - 1/12z^2 + 3/360z^4 - 5/1260z^6
      //     + 7/1680z^8 - 9/1188z^10 + ...
      //
      // (Abramowitz&Stegun, page 259, formula 6.3.18
      dgam += Lanczos_approximation_psi (z_m);
    }
  return dgam;
}

// explicit instantiations
template Complex psi<double> (const Complex& z);
template FloatComplex psi<float> (const FloatComplex& z);


template <typename T>
static inline void
fortran_psifn (const T z, const octave_idx_type n, T* ans,
               octave_idx_type* ierr);

template <>
inline void
fortran_psifn<double> (const double z, const octave_idx_type n,
                       double* ans, octave_idx_type* ierr)
{
  octave_idx_type flag = 0;
  F77_XFCN (dpsifn, DPSIFN, (&z, n, 1, 1, ans, &flag, ierr));
}

template <>
inline void
fortran_psifn<float> (const float z, const octave_idx_type n,
                      float* ans, octave_idx_type* ierr)
{
  octave_idx_type flag = 0;
  F77_XFCN (psifn, PSIFN, (&z, n, 1, 1, ans, &flag, ierr));
}

template <typename T>
T
psi (const octave_idx_type n, const T z)
{
  T ans;
  octave_idx_type ierr = 0;
  fortran_psifn<T> (z, n, &ans, &ierr);
  if (ierr == 0)
    {
      // Remember that psifn and dpsifn return scales values
      // When n is 1: do nothing since ((-1)**(n+1)/gamma(n+1)) == 1
      // When n is 0: change sign since ((-1)**(n+1)/gamma(n+1)) == -1
      if (n > 1)
        // FIXME: xgamma here is a killer for our precision since it grows
        //        way too fast.
        ans = ans / (pow (-1.0, n + 1) / xgamma (double (n+1)));
      else if (n == 0)
        ans = -ans;
    }
  else if (ierr == 2)
    ans = - octave_Inf;
  else // we probably never get here
    ans = octave_NaN;

  return ans;
}

// explicit instantiations
template double psi<double> (const octave_idx_type n, const double z);
template float  psi<float>  (const octave_idx_type n, const float z);