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GRASS Programmer's Manual
6.5.svn(2012)-r51648
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00001 /* rmmult.c CCMATH mathematics library source code. 00002 * 00003 * Copyright (C) 2000 Daniel A. Atkinson All rights reserved. 00004 * This code may be redistributed under the terms of the GNU library 00005 * public license (LGPL). ( See the lgpl.license file for details.) 00006 * ------------------------------------------------------------------------ 00007 */ 00008 #include <stdlib.h> 00009 void rmmult(double *rm, double *a, double *b, int n, int m, int l) 00010 { 00011 double z, *q0, *p, *q; 00012 00013 int i, j, k; 00014 00015 q0 = (double *)calloc(m, sizeof(double)); 00016 for (i = 0; i < l; ++i, ++rm) { 00017 for (k = 0, p = b + i; k < m; p += l) 00018 q0[k++] = *p; 00019 for (j = 0, p = a, q = rm; j < n; ++j, q += l) { 00020 for (k = 0, z = 0.; k < m;) 00021 z += *p++ * q0[k++]; 00022 *q = z; 00023 } 00024 } 00025 free(q0); 00026 }