/* fft/hc_unpack.c

 * 

 * Copyright (C) 1996, 1997, 1998, 1999, 2000, 2007 Brian Gough

 * 

 * This program 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.

 * 

 * This program 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; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.

 */

int

FUNCTION(gsl_fft_halfcomplex,unpack) (const BASE halfcomplex_coefficient[],

                                      BASE complex_coefficient[],

                                      const size_t stride, const size_t n)

{

  size_t i;

  if (n == 0)

    {

      GSL_ERROR ("length n must be positive integer", GSL_EDOM);

    }

  REAL(complex_coefficient,stride,0) = halfcomplex_coefficient[0];

  IMAG(complex_coefficient,stride,0) = 0.0;

  for (i = 1; i < n - i; i++)

    {

      const ATOMIC hc_real = halfcomplex_coefficient[(2 * i - 1) * stride];

      const ATOMIC hc_imag = halfcomplex_coefficient[2 * i * stride];

      REAL(complex_coefficient,stride,i) = hc_real;

      IMAG(complex_coefficient,stride,i) = hc_imag;

      REAL(complex_coefficient,stride,n - i) = hc_real;

      IMAG(complex_coefficient,stride,n - i) = -hc_imag;

    }

  if (i == n - i)

    {

      REAL(complex_coefficient,stride,i) = halfcomplex_coefficient[(n - 1) * stride];

      IMAG(complex_coefficient,stride,i) = 0.0;

    }

  return 0;

}

int

FUNCTION(gsl_fft_halfcomplex,radix2_unpack) (const BASE halfcomplex_coefficient[],

                                             BASE complex_coefficient[],

                                             const size_t stride, const size_t n)

{

  size_t i;

  if (n == 0)

    {

      GSL_ERROR ("length n must be positive integer", GSL_EDOM);

    }

  REAL(complex_coefficient,stride,0) = halfcomplex_coefficient[0];

  IMAG(complex_coefficient,stride,0) = 0.0;

  for (i = 1; i < n - i; i++)

    {

      const ATOMIC hc_real = halfcomplex_coefficient[i * stride];

      const ATOMIC hc_imag = halfcomplex_coefficient[(n - i) * stride];

      REAL(complex_coefficient,stride,i) = hc_real;

      IMAG(complex_coefficient,stride,i) = hc_imag;

      REAL(complex_coefficient,stride,n - i) = hc_real;

      IMAG(complex_coefficient,stride,n - i) = -hc_imag;

    }

  if (i == n - i)

    {

      REAL(complex_coefficient,stride,i) = halfcomplex_coefficient[i * stride];

      IMAG(complex_coefficient,stride,i) = 0.0;

    }

  return 0;

}