算法-->矩阵运算

梦里梦外; 2022-06-11 09:47 194阅读 0赞

package 矩阵运算;
    
    /** * 矩阵的加法，减法，乘法 * * @author 朱珍珍 * */
    public class juzheng {
        static void Add(double A[][], double B[][], int m, int n, double C[][]) {
            // A,B参与的矩阵，m,n列数C为相加后的 结果
            int i, j;
            for (i = 0; i < m; i++) {
                for (j = 0; j < n; j++) {
                    C[i][j] = A[i][j] + B[i][j];
                }
    
            }
        }
    
        static void Mat(double A[][], double B[][], int m, int n, double C[][]) {
            // A,B参与的矩阵，m,n列数C为相加后的 结果
            int i, j;
            for (i = 0; i < m; i++) {
                for (j = 0; j < n; j++) {
                    C[i][j] = A[i][j] - B[i][j];
                }
    
            }
        }
    
        static void mul(double A[][], double B[][], int m, int n, int k, double C[][]) {
            // k为矩阵B的列数
            int i, j, l;
            for (i = 0; i < m; i++) {
                for (j = 0; j < n; j++) {
                    C[i][j] = 0;
                    for (l = 0; l < k; l++) {
                        C[i][j] += (A[i][l] * B[l][j]);// 相乘累加
                    }
                }
    
            }
    
        }
    
        public static void main(String[] args) {
            double A[][] = { { 1.0, 2.0, 3.0 }, { 4.0, 5.0, 6.0 }, { 7.0, 8.0, 9.0 }
    
            };
            double B[][] = { { 2.0, -2.0, 1.0 }, { 1.0, 3.0, 9.0 }, { 17.0, -3.0, 7.0 }
    
            };
            double[][] C = new double[3][3];
            int m, n, i, j, k;
            m = 3;// 行数
            n = 3;// 列数
            k = 3;
    
            System.out.print("矩阵A和B想 加的结果 为：\n");
            Add(A, B, m, n, C);
    
            for (i = 0; i < m; i++) {
                for (j = 0; j < n; j++) {
                    System.out.printf("%10.6f", C[i][j]);
                }
                System.out.print("\n");
            }
            System.out.print("\n");
            System.out.print("矩阵A和B想 减的结果 为：\n");
            Mat(A, B, m, n, C);
    
            for (i = 0; i < m; i++) {
                for (j = 0; j < n; j++) {
                    System.out.printf("%10.6f", C[i][j]);
                }
                System.out.print("\n");
            }
            System.out.print("\n");
            System.out.print("矩阵A和B想 乘的结果 为：\n");
            mul(A, B, m, n, k, C);
            for (i = 0; i < m; i++) {
                for (j = 0; j < n; j++) {
                    System.out.printf("%15.6f", C[i][j]);
                }
                System.out.print("\n");
            }
        }
    }

![这里写图片描述][SouthEast]

[SouthEast]: /images/20220611/5a1895662bf44becad61a9ca1f65fce9.png