3 * Copyright (C) 1996, 1997, 1998, 1999, 2000, 2007 Brian Gough
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 3 of the License, or (at
8 * your option) any later version.
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
21 FUNCTION(gsl_fft_halfcomplex,unpack) (const BASE halfcomplex_coefficient[],
22 BASE complex_coefficient[],
23 const size_t stride, const size_t n)
29 GSL_ERROR ("length n must be positive integer", GSL_EDOM);
32 REAL(complex_coefficient,stride,0) = halfcomplex_coefficient[0];
33 IMAG(complex_coefficient,stride,0) = 0.0;
35 for (i = 1; i < n - i; i++)
37 const ATOMIC hc_real = halfcomplex_coefficient[(2 * i - 1) * stride];
38 const ATOMIC hc_imag = halfcomplex_coefficient[2 * i * stride];
40 REAL(complex_coefficient,stride,i) = hc_real;
41 IMAG(complex_coefficient,stride,i) = hc_imag;
42 REAL(complex_coefficient,stride,n - i) = hc_real;
43 IMAG(complex_coefficient,stride,n - i) = -hc_imag;
48 REAL(complex_coefficient,stride,i) = halfcomplex_coefficient[(n - 1) * stride];
49 IMAG(complex_coefficient,stride,i) = 0.0;
57 FUNCTION(gsl_fft_halfcomplex,radix2_unpack) (const BASE halfcomplex_coefficient[],
58 BASE complex_coefficient[],
59 const size_t stride, const size_t n)
65 GSL_ERROR ("length n must be positive integer", GSL_EDOM);
68 REAL(complex_coefficient,stride,0) = halfcomplex_coefficient[0];
69 IMAG(complex_coefficient,stride,0) = 0.0;
71 for (i = 1; i < n - i; i++)
73 const ATOMIC hc_real = halfcomplex_coefficient[i * stride];
74 const ATOMIC hc_imag = halfcomplex_coefficient[(n - i) * stride];
76 REAL(complex_coefficient,stride,i) = hc_real;
77 IMAG(complex_coefficient,stride,i) = hc_imag;
78 REAL(complex_coefficient,stride,n - i) = hc_real;
79 IMAG(complex_coefficient,stride,n - i) = -hc_imag;
84 REAL(complex_coefficient,stride,i) = halfcomplex_coefficient[i * stride];
85 IMAG(complex_coefficient,stride,i) = 0.0;