矩阵乘法通过将2个矩阵相乘得到一个新的矩阵。但这只有在第一矩阵的列等于第二矩阵的行的情况下才有可能。下面给出了具有平方矩阵的矩阵乘法的示例。
public class Example { public static void main(String args[]) { int n = 3; int[][] a = { {5, 2, 3}, {2, 6, 3}, {6, 9, 1} }; int[][] b = { {2, 7, 5}, {1, 4, 3}, {1, 2, 1} }; int[][] c = new int[n][n]; System.out.println("矩阵A:"); for (int i = 0; i < n; i++) { for (int j = 0; j < n; j++) { System.out.print(a[i][j] + " "); } System.out.println(); } System.out.println("矩阵B:"); for (int i = 0; i < n; i++) { for (int j = 0; j < n; j++) { System.out.print(b[i][j] + " "); } System.out.println(); } for (int i = 0; i < n; i++) { for (int j = 0; j < n; j++){ for (int k = 0; k < n; k++) { c[i][j] = c[i][j] + a[i][k] * b[k][j]; } } } System.out.println("两个矩阵的乘积为:"); for (int i = 0; i < n; i++) { for (int j = 0; j < n; j++) { System.out.print(c[i][j] + " "); } System.out.println(); } } }
输出结果
矩阵A: 5 2 3 2 6 3 6 9 1 矩阵B: 2 7 5 1 4 3 1 2 1 两个矩阵的乘积为: 15 49 34 13 44 31 22 80 58