1 /* linalg/multiply.c
2 *
3 * Copyright (C) 1996, 1997, 1998, 1999, 2000, 2007 Gerard Jungman, Brian Gough
4 *
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.
9 *
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.
14 *
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.
18 */
19
20 /* Author: G. Jungman */
21
22 #include "gsl__config.h"
23 #include <stdlib.h>
24 #include "gsl_math.h"
25 #include "gsl_linalg.h"
26
27 #define SWAP_SIZE_T(a, b) do { size_t swap_tmp = a; a = b; b = swap_tmp; } while(0)
28
29 int
gsl_linalg_matmult(const gsl_matrix * A,const gsl_matrix * B,gsl_matrix * C)30 gsl_linalg_matmult (const gsl_matrix * A, const gsl_matrix * B, gsl_matrix * C)
31 {
32 if (A->size2 != B->size1 || A->size1 != C->size1 || B->size2 != C->size2)
33 {
34 GSL_ERROR ("matrix sizes are not conformant", GSL_EBADLEN);
35 }
36 else
37 {
38 double a, b;
39 double temp;
40 size_t i, j, k;
41
42 for (i = 0; i < C->size1; i++)
43 {
44 for (j = 0; j < C->size2; j++)
45 {
46 a = gsl_matrix_get (A, i, 0);
47 b = gsl_matrix_get (B, 0, j);
48 temp = a * b;
49 for (k = 1; k < A->size2; k++)
50 {
51 a = gsl_matrix_get (A, i, k);
52 b = gsl_matrix_get (B, k, j);
53 temp += a * b;
54 }
55 gsl_matrix_set (C, i, j, temp);
56 }
57 }
58
59 return GSL_SUCCESS;
60 }
61 }
62
63
64 int
gsl_linalg_matmult_mod(const gsl_matrix * A,gsl_linalg_matrix_mod_t modA,const gsl_matrix * B,gsl_linalg_matrix_mod_t modB,gsl_matrix * C)65 gsl_linalg_matmult_mod (const gsl_matrix * A, gsl_linalg_matrix_mod_t modA,
66 const gsl_matrix * B, gsl_linalg_matrix_mod_t modB,
67 gsl_matrix * C)
68 {
69 if (modA == GSL_LINALG_MOD_NONE && modB == GSL_LINALG_MOD_NONE)
70 {
71 return gsl_linalg_matmult (A, B, C);
72 }
73 else
74 {
75 size_t dim1_A = A->size1;
76 size_t dim2_A = A->size2;
77 size_t dim1_B = B->size1;
78 size_t dim2_B = B->size2;
79 size_t dim1_C = C->size1;
80 size_t dim2_C = C->size2;
81
82 if (modA & GSL_LINALG_MOD_TRANSPOSE)
83 SWAP_SIZE_T (dim1_A, dim2_A);
84 if (modB & GSL_LINALG_MOD_TRANSPOSE)
85 SWAP_SIZE_T (dim1_B, dim2_B);
86
87 if (dim2_A != dim1_B || dim1_A != dim1_C || dim2_B != dim2_C)
88 {
89 GSL_ERROR ("matrix sizes are not conformant", GSL_EBADLEN);
90 }
91 else
92 {
93 double a, b;
94 double temp;
95 size_t i, j, k;
96 size_t a1, a2, b1, b2;
97
98 for (i = 0; i < dim1_C; i++)
99 {
100 for (j = 0; j < dim2_C; j++)
101 {
102 a1 = i;
103 a2 = 0;
104 b1 = 0;
105 b2 = j;
106 if (modA & GSL_LINALG_MOD_TRANSPOSE)
107 SWAP_SIZE_T (a1, a2);
108 if (modB & GSL_LINALG_MOD_TRANSPOSE)
109 SWAP_SIZE_T (b1, b2);
110
111 a = gsl_matrix_get (A, a1, a2);
112 b = gsl_matrix_get (B, b1, b2);
113 temp = a * b;
114
115 for (k = 1; k < dim2_A; k++)
116 {
117 a1 = i;
118 a2 = k;
119 b1 = k;
120 b2 = j;
121 if (modA & GSL_LINALG_MOD_TRANSPOSE)
122 SWAP_SIZE_T (a1, a2);
123 if (modB & GSL_LINALG_MOD_TRANSPOSE)
124 SWAP_SIZE_T (b1, b2);
125 a = gsl_matrix_get (A, a1, a2);
126 b = gsl_matrix_get (B, b1, b2);
127 temp += a * b;
128 }
129
130 gsl_matrix_set (C, i, j, temp);
131 }
132 }
133
134 return GSL_SUCCESS;
135 }
136 }
137 }
138