/* fft/test_real.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.

 */

#include "bitreverse.h"

#include "signals.h"

#include "compare.h"

void FUNCTION(test_real,func) (size_t stride, size_t n);

void FUNCTION(test_real,bitreverse_order) (size_t stride, size_t n);

void FUNCTION(test_real,radix2) (size_t stride, size_t n);

void FUNCTION(test_real,func) (size_t stride, size_t n) 

{

  size_t i ;

  int status ;

  TYPE(gsl_fft_real_wavetable) * rw ;

  TYPE(gsl_fft_halfcomplex_wavetable) * hcw ;

  TYPE(gsl_fft_real_workspace) * rwork ;

  BASE * real_data = (BASE *) malloc (n * stride * sizeof (BASE));

  BASE * complex_data = (BASE *) malloc (2 * n * stride * sizeof (BASE));

  BASE * complex_tmp = (BASE *) malloc (2 * n * stride * sizeof (BASE));

  BASE * fft_complex_data = (BASE *) malloc (2 * n * stride * sizeof (BASE));

  for (i = 0 ; i < n * stride ; i++)

    {

      real_data[i] = (BASE)i ;

    }

  for (i = 0 ; i < 2 * n * stride ; i++)

    {

      complex_data[i] = (BASE)(i + 1000.0) ;

      complex_tmp[i] = (BASE)(i + 2000.0) ;

      fft_complex_data[i] = (BASE)(i + 3000.0) ;

    }

  gsl_set_error_handler (NULL); /* abort on any errors */

  /* mixed radix real fft */

  rw = FUNCTION(gsl_fft_real_wavetable,alloc) (n);

  gsl_test (rw == 0, NAME(gsl_fft_real_wavetable) 

            "_alloc, n = %d, stride = %d", n, stride);

  rwork = FUNCTION(gsl_fft_real_workspace,alloc) (n);

  gsl_test (rwork == 0, NAME(gsl_fft_real_workspace) 

            "_alloc, n = %d", n);

  FUNCTION(fft_signal,real_noise) (n, stride, complex_data, fft_complex_data);

  memcpy (complex_tmp, complex_data, 2 * n * stride * sizeof (BASE));

  for (i = 0; i < n; i++)

    {

      real_data[i*stride] = REAL(complex_data,stride,i);

    }

  FUNCTION(gsl_fft_real,transform) (real_data, stride, n, rw, rwork);

  FUNCTION(gsl_fft_halfcomplex,unpack) (real_data, complex_data, stride, n);

  status = FUNCTION(compare_complex,results) ("dft", fft_complex_data,

                                              "fft of noise", complex_data,

                                              stride, n, 1e6);

  gsl_test (status, NAME(gsl_fft_real) 

            " with signal_real_noise, n = %d, stride = %d", n, stride);

  /* compute the inverse fft */

  hcw = FUNCTION(gsl_fft_halfcomplex_wavetable,alloc) (n);

  gsl_test (hcw == 0, NAME(gsl_fft_halfcomplex_wavetable) 

            "_alloc, n = %d, stride = %d", n, stride);

  status = FUNCTION(gsl_fft_halfcomplex,transform) (real_data, stride, n, hcw, rwork);

  for (i = 0; i < n; i++)

    {

      real_data[i*stride] /= n;

    }

  FUNCTION(gsl_fft_real,unpack) (real_data, complex_data, stride, n);

  status = FUNCTION(compare_complex,results) ("orig", complex_tmp,

                                              "fft inverse", complex_data,

                                              stride, n, 1e6);

  gsl_test (status, NAME(gsl_fft_halfcomplex) 

            " with data from signal_noise, n = %d, stride = %d", n, stride);

  FUNCTION(gsl_fft_real_workspace,free) (rwork);

  FUNCTION(gsl_fft_real_wavetable,free) (rw);

  FUNCTION(gsl_fft_halfcomplex_wavetable,free) (hcw);

  free(real_data) ;

  free(complex_data) ;

  free(complex_tmp) ;

  free(fft_complex_data) ;

}

void 

FUNCTION(test_real,bitreverse_order) (size_t stride, size_t n) 

{

  int status ;

  size_t logn, i ;

  BASE * tmp = (BASE *) malloc (n * stride * sizeof (BASE));

  BASE * data = (BASE *) malloc (n * stride * sizeof (BASE));

  BASE * reversed_data = (BASE *) malloc (n * stride * sizeof (BASE));

  for (i = 0; i <  stride * n; i++) 

    {

      data[i] = (BASE)i ;

    }

  memcpy (tmp, data, n * stride * sizeof(BASE)) ;

  logn = 0 ;  while (n > (1U <

  /* do a naive bit reversal as a baseline for testing the other routines */

  for (i = 0; i < n; i++) 

    {

      size_t i_tmp = i ;

      size_t j = 0 ;

      size_t bit ;

      for (bit = 0; bit < logn; bit++)

        {

          j <<= 1;              /* reverse shift i into j */

          j |= i_tmp & 1;

          i_tmp >>= 1;

        }

      reversed_data[j*stride] = data[i*stride] ;

    }

  FUNCTION(fft_real,bitreverse_order) (data, stride, n, logn);

  status = FUNCTION(compare_real,results) ("naive bit reverse", 

                                           reversed_data,

                                           "fft_complex_bitreverse_order", 

                                           data,

                                           stride, n, 1e6);

  gsl_test (status, NAME(fft_real) "_bitreverse_order, n = %d", n);

  free (reversed_data) ;

  free (data) ;

  free (tmp) ;

}

void FUNCTION(test_real,radix2) (size_t stride, size_t n) 

{

  size_t i ;

  int status ;

  BASE * real_data = (BASE *) malloc (n * stride * sizeof (BASE));

  BASE * complex_data = (BASE *) malloc (2 * n * stride * sizeof (BASE));

  BASE * complex_tmp = (BASE *) malloc (2 * n * stride * sizeof (BASE));

  BASE * fft_complex_data = (BASE *) malloc (2 * n * stride * sizeof (BASE));

  for (i = 0 ; i < n * stride ; i++)

    {

      real_data[i] = (BASE)i ;

    }

  for (i = 0 ; i < 2 * n * stride ; i++)

    {

      complex_data[i] = (BASE)(i + 1000.0) ;

      complex_tmp[i] = (BASE)(i + 2000.0) ;

      fft_complex_data[i] = (BASE)(i + 3000.0) ;

    }

  gsl_set_error_handler (NULL); /* abort on any errors */

  /* radix-2 real fft */

  FUNCTION(fft_signal,real_noise) (n, stride, complex_data, fft_complex_data);

  memcpy (complex_tmp, complex_data, 2 * n * stride * sizeof (BASE));

  for (i = 0; i < n; i++)

    {

      real_data[i*stride] = REAL(complex_data,stride,i);

    }

  FUNCTION(gsl_fft_real,radix2_transform) (real_data, stride, n);

  FUNCTION(gsl_fft_halfcomplex,radix2_unpack) (real_data, complex_data, stride, n);

  status = FUNCTION(compare_complex,results) ("dft", fft_complex_data,

                                              "fft of noise", complex_data,

                                              stride, n, 1e6);

  gsl_test (status, NAME(gsl_fft_real) 

            "_radix2 with signal_real_noise, n = %d, stride = %d", n, stride);

  /* compute the inverse fft */

  status = FUNCTION(gsl_fft_halfcomplex,radix2_transform) (real_data, stride, n);

  for (i = 0; i < n; i++)

    {

      real_data[i*stride] /= n;

    }

  FUNCTION(gsl_fft_real,unpack) (real_data, complex_data, stride, n);

  status = FUNCTION(compare_complex,results) ("orig", complex_tmp,

                                              "fft inverse", complex_data,

                                              stride, n, 1e6);

  gsl_test (status, NAME(gsl_fft_halfcomplex) 

            "_radix2 with data from signal_noise, n = %d, stride = %d", n, stride);

  free(real_data) ;

  free(complex_data) ;

  free(complex_tmp) ;

  free(fft_complex_data) ;

}