summaryrefslogtreecommitdiff
path: root/src/common/matrix.c
diff options
context:
space:
mode:
Diffstat (limited to 'src/common/matrix.c')
-rw-r--r--src/common/matrix.c63
1 files changed, 0 insertions, 63 deletions
diff --git a/src/common/matrix.c b/src/common/matrix.c
deleted file mode 100644
index 60f9afb..0000000
--- a/src/common/matrix.c
+++ /dev/null
@@ -1,63 +0,0 @@
1#include "common/matrix.h"
2#include <assert.h>
3#include <memory.h>
4#include <stdlib.h>
5#include "common/mem.h"
6
7static inline IntSquareMatrix *matrix_without_row(IntSquareMatrix *target, IntSquareMatrix *origin,
8 IntVector omitted_row) {
9 int origin_row, target_row;
10
11 for (origin_row = 0, target_row = 0; origin_row < origin->dim; ++origin_row)
12 if (origin_row != omitted_row)
13 target->elements[target_row++] = origin->elements[origin_row];
14
15 return target;
16}
17
18static inline IntVector det_dev_sign(IntVector row, IntVector col) {
19 assert(row > 0 && col > 0);
20 return ((row + col) % 2 == 0) ? 1 : -1;
21}
22
23static inline IntVector det_reduce(IntSquareMatrix *matrix) {
24 IntSquareMatrix sub_matrix;
25 int row;
26 IntVector det = 0;
27
28 assert(matrix->dim > 2);
29
30 sub_matrix.dim = matrix->dim - 1;
31 sub_matrix.elements = malloc_or_die(sub_matrix.dim * sizeof(IntVector *));
32
33 for (row = 0; row < matrix->dim; ++row)
34 det += matrix->elements[row][matrix->dim - 1]
35 * det_dev_sign(row + 1, matrix->dim)
36 * matrix_int_det(matrix_without_row(&sub_matrix, matrix, row));
37
38
39 free(sub_matrix.elements);
40 return det;
41}
42
43IntVector matrix_int_det(IntSquareMatrix *matrix) {
44 assert(matrix->dim > 0);
45 switch (matrix->dim) {
46 case 1:
47 return matrix->elements[0][0];
48
49 case 2:
50 return matrix->elements[0][0] * matrix->elements[1][1] - matrix->elements[0][1] * matrix->elements[1][0];
51
52 default:
53 return det_reduce(matrix);
54 }
55}
56
57void matrix_reshape(IntVector **bi_dim, IntVector *flat, int width, int height) {
58 int row;
59 assert(width > 0 && height > 0);
60
61 for (row = 0; row < height; ++row)
62 bi_dim[row] = flat + row * width;
63}