include/gsl/gsl_fft.h

0001 /* fft/gsl_fft.h
0002  *
0003  * Copyright (C) 1996, 1997, 1998, 1999, 2000, 2007 Brian Gough
0004  *
0005  * This program is free software; you can redistribute it and/or modify
0006  * it under the terms of the GNU General Public License as published by
0007  * the Free Software Foundation; either version 3 of the License, or (at
0008  * your option) any later version.
0009  *
0010  * This program is distributed in the hope that it will be useful, but
0011  * WITHOUT ANY WARRANTY; without even the implied warranty of
0012  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
0013  * General Public License for more details.
0014  *
0015  * You should have received a copy of the GNU General Public License
0016  * along with this program; if not, write to the Free Software
0017  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
0018  */
0019
0020 #ifndef __GSL_FFT_H__
0021 #define __GSL_FFT_H__
0022
0023 #include <gsl/gsl_complex.h>
0024
0025 #undef __BEGIN_DECLS
0026 #undef __END_DECLS
0027 #ifdef __cplusplus
0028 # define __BEGIN_DECLS extern "C" {
0029 # define __END_DECLS }
0030 #else
0031 # define __BEGIN_DECLS /* empty */
0032 # define __END_DECLS /* empty */
0033 #endif
0034
0035 __BEGIN_DECLS
0036
0037 typedef enum
0038   {
0039     gsl_fft_forward = -1, gsl_fft_backward = +1
0040   }
0041 gsl_fft_direction;
0042
0043 /* this gives the sign in the formula
0044
0045    h(f) = \sum x(t) exp(+/- 2 pi i f t)
0046
0047    where - is the forward transform direction and + the inverse direction */
0048
0049 __END_DECLS
0050
0051 #endif /* __GSL_FFT_H__ */