text: /* fft/gsl_fft.h
   * 
   * 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.
   */
  
  #ifndef __GSL_FFT_H__
  #define __GSL_FFT_H__
  
  #include <gsl/gsl_complex.h>
  
  #undef __BEGIN_DECLS
  #undef __END_DECLS
  #ifdef __cplusplus
  # define __BEGIN_DECLS extern "C" {
  # define __END_DECLS }
  #else
  # define __BEGIN_DECLS /* empty */
  # define __END_DECLS /* empty */
  #endif
  
  __BEGIN_DECLS
  
  #ifndef GSL_DISABLE_DEPRECATED
  typedef enum
    {
      forward = -1, backward = +1,
      gsl_fft_forward = -1, gsl_fft_backward = +1      
    }
  gsl_fft_direction;
  #else
  typedef enum
    {
      gsl_fft_forward = -1, gsl_fft_backward = +1   
    }
  gsl_fft_direction;
  #endif
  
  /* this gives the sign in the formula
  
     h(f) = \sum x(t) exp(+/- 2 pi i f t) 
         
     where - is the forward transform direction and + the inverse direction */
  
  __END_DECLS
  
  #endif /* __GSL_FFT_H__ */
  