Chapter4_5_3

public class Ch4_5_3 {
    //实现矩阵的加法、减法和乘法
    public static void main(String[] args) {
        double [][] arry1  = {{1,2,3},{4,5,6},{7,8,9}};
        double [][] arry2  = {{1,2,3},{4,5,6},{7,8,9}};

        new Ch4_5_3().add(arry1,arry2);
        new Ch4_5_3().subtraction(arry1,arry2);
        new Ch4_5_3().multipication(arry1,arry2);
    }

    public void add(double[][]arry1,double[][]arry2){
        if(arry1.length== arry2.length&&arry1[0].length==arry2[0].length){
            double[][] arry = new double[arry1.length][arry1[0].length];
            for(int i = 0;i<arry1.length;i++){
                for(int j = 0;j<arry1[0].length;j++){
                    arry[i][j]=arry1[i][j]+arry2[i][j];
                }
            }

            for(int i = 0;i<arry.length;i++){
                for (int j = 0;j<arry[0].length;j++){
                    System.out.print(arry[i][j]+"\t");
                }
                System.out.println();
            }

        }
    }

    public void subtraction(double[][]arry1,double[][]arry2){
        if(arry1.length==arry2.length&&arry1[0].length==arry2[0].length){
            double[][] arry = new double[arry1.length][arry1[0].length];
            for (int i = 0; i < arry1.length; i++) {
                for(int j = 0;j<arry1[0].length;j++){
                    arry[i][j] = arry1[i][j]-arry2[i][j];
                }
            }

            for (int i = 0; i < arry.length; i++) {
                for(int j=0;j<arry[0].length;j++){
                    System.out.print(arry[i][j]+"\t");
                }
                System.out.println();
            }
        }

    }

    public void multipication(double[][]arry1,double[][]arry2){
        if(arry1[0].length==arry2.length){
            double[][] arry = new double[arry1.length][arry2[0].length];

            for (int i = 0; i < arry1.length; i++) {
                for(int j=0;j<arry2[0].length;j++){
                    for(int z = 0;z<arry1[0].length;z++){
                        arry[i][j] +=(arry1[i][z]*arry2[z][j]);
                    }
                }
            }

            for(int i = 0;i<arry.length;i++){
                for(int j =0;j<arry[0].length;j++){
                    System.out.print(arry[i][j]+"\t");
                }
                System.out.println();
            }
        }
    }
}