mirror of
https://github.com/VK3FNG/soundmodem.git
synced 2025-12-06 03:01:59 +01:00
81 lines
2.1 KiB
C
81 lines
2.1 KiB
C
/*
|
|
* Matrix operations library
|
|
*
|
|
* Copyright (C) 1999-2000
|
|
* Thomas Sailer, <sailer@ife.ee.ethz.ch>
|
|
*
|
|
* 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 2 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
|
*/
|
|
|
|
#ifdef HAVE_CONFIG_H
|
|
#include "config.h"
|
|
#endif
|
|
|
|
/* AIX requires this to be the first thing in the file. */
|
|
#ifndef __GNUC__
|
|
# if HAVE_ALLOCA_H
|
|
# include <alloca.h>
|
|
# else
|
|
# ifdef _AIX
|
|
#pragma alloca
|
|
# else
|
|
# ifndef alloca /* predefined by HP cc +Olibcalls */
|
|
char *alloca ();
|
|
# endif
|
|
# endif
|
|
# endif
|
|
#endif
|
|
|
|
#include "mat.h"
|
|
#include <math.h>
|
|
#include <stdio.h>
|
|
|
|
/*
|
|
* This routine calculates A*c=b iteratively, using the Gauss-Seidel iteration method
|
|
*/
|
|
|
|
int fcgaussseidel(const cplxfloat_t *a, const cplxfloat_t *b, cplxfloat_t *c, unsigned int d, unsigned int iter)
|
|
{
|
|
cplxfloat_t *adiag;
|
|
unsigned int i, j, k;
|
|
cplxfloat_t s;
|
|
|
|
adiag = alloca(d*sizeof(adiag[0]));
|
|
/* initial vector */
|
|
for (i = 1; i < d; i++)
|
|
cplx(c[i], 0, 0);
|
|
cplx(c[0], 1, 0);
|
|
/* check for diagonal */
|
|
for (i = 0; i < d; i++) {
|
|
if (real(a[i*d+i]) == 0 && imag(a[i*d+i]) == 0) {
|
|
fprintf(stderr, "fcgaussseidel: matrix diagonal zero a[%u][%u]=%g%+gi\n", i, i, real(a[i*d+i]), imag(a[i*d+i]));
|
|
return -1;
|
|
}
|
|
cinv(adiag[i], a[i*d+i]);
|
|
}
|
|
/* iteration */
|
|
for (i = 0; i < iter; i++) {
|
|
for (j = 0; j < d; j++) {
|
|
s = b[j];
|
|
for (k = 0; k < j; k++)
|
|
cmsub(s, a[j*d+k], c[k]);
|
|
for (k = j+1; k < d; k++)
|
|
cmsub(s, a[j*d+k], c[k]);
|
|
cmul(c[j], s, adiag[j]);
|
|
}
|
|
}
|
|
return 0;
|
|
}
|