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1 package com.etymon.pj.util;
2
3 public class TMatrix {
4
5
7
10 public static float[][] init() {
11 float[][] id = { {1, 0, 0},
12 {0, 1, 0},
13 {0, 0, 1} };
14 return id;
15 }
16
17 public static String  toString(float[][] m) {
18 return "{ {" + m[0][0] + ", " + m[0][1] + ", " + m[0][2] + "},\n" +
19 " {" + m[1][0] + ", " + m[1][1] + ", " + m[1][2] + "},\n" +
20 " {" + m[2][0] + ", " + m[2][1] + ", " + m[2][2] + "} }";
21 }
22
23 public static float[][] toMatrix(float a, float b, float c, float d, float x, float y) {
24 float[][] m = init();
25 m[0][0] = a;
26 m[0][1] = b;
27 m[1][0] = c;
28 m[1][1] = d;
29 m[2][0] = x;
30 m[2][1] = y;
31 return m;
32 }
33
34 public static float[][] clone(float[][] m) {
35 float[][] n = init();
36 for (int r = 0; r < 3; r++) {
37 for (int c = 0; c < 3; c++) {
38 n[r][c] = m[r][c];
39 }
40 }
41 return n;
42 }
43
44 public static float[][] toMatrix(float x, float y) {
45 float[][] m = init();
46 m[2][0] = x;
47 m[2][1] = y;
48 return m;
49 }
50
51 public static float[][] multiply(float[][] a, float[][] b) {
52 if (a[0].length != b.length) {
53 return null;
54 }
55 float[][] c = new float[a.length][b[0].length];
56 for (int i = 0; i < a.length; i++) {
57 for (int k = 0; k < b[0].length; k++) {
58 float s = 0;
59 for (int j = 0; j < b.length; j++) {
60 s = s + a[i][j] * b[j][k];
61 }
62 c[i][k] = s;
63 }
64 }
65 return c;
66 }
67
68 public static float[][] IDENTITY = { {1, 0, 0},
69 {0, 1, 0},
70 {0, 0, 1} };
71
72 }
73 |
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