Java课程设计 矩阵类 实现加、减、乘法

矩阵类：

// Filename: Matrix.javaclass Matrix {Matrix(){}    Matrix(int r, int c)    {    row = r;    col = c;    matrix = new double[r][c];    }        Matrix(double [][] m, int r, int c)    {    row = r;    col = c;        matrix = m;    }        Matrix(double [][] m)     {    row = m.length;    col = m[0].length;        matrix = m;    }        Matrix add(Matrix b)    {    if((row != b.row) && (col != b.col))    {    System.out.println("Matrix A can't add Matri B!");    System.exit(1);    }        Matrix tmp = new Matrix(row, col);        for(int i = 0; i < row; i++)    for(int j = 0; j < col; j++)    {    tmp.matrix[i][j] = matrix[i][j] + b.matrix[i][j];    }        return tmp;    }        Matrix sub(Matrix b)    {    if((row != b.row) && (col != b.col))    {    System.out.println("Matrix A can't subtract Matri B!");    System.exit(1);    }        Matrix tmp = new Matrix(row, col);        for(int i = 0; i < row; i++)    for(int j = 0; j < col; j++)    {    tmp.matrix[i][j] = matrix[i][j] - b.matrix[i][j];    }        return tmp;    }        Matrix mul(Matrix b)    {    if(col != b.row)    {    System.out.println("Matrix A can't multiply Matrix B!");    System.exit(1);    }        Matrix tmp = new Matrix(row, b.col);    for(int i = 0; i < row; i++)    for(int j = 0; j < b.col; j++)    {    tmp.matrix[i][j] = 0.0;    for(int k = 0; k < b.row; k++)    {    tmp.matrix[i][j] += matrix[i][k] * b.matrix[k][j];    }    }    return tmp;    }        void print()    {    for(int i = 0; i < row; i++)    {    System.out.print(matrix[i][0]);    for(int j = 1; j < col; j++)    {    System.out.print(" " + matrix[i][j]);    }    System.out.println("");    }    }        private int col;//列数    private int row;//行数    private double [][] matrix;//保存矩阵}

测试程序：

// Filename: MatrixDriveTestimport java.io.*;import java.util.*;public class MatrixDriveTest {    public static void main(String [] args) throws Exception    {        int m, n;//m保存行数, n保存列数    double [][] matrix;//保存矩阵        Scanner in = new Scanner(System.in);        System.out.println("Input a m×n matrix...");        m = in.nextInt();    n = in.nextInt();        matrix = new double[m][n];        //System.out.println("m = " + matrix.length);    //System.out.println("n = " + matrix[0].length);        for(int i = 0; i < m; i++)    for(int j = 0; j < n; j++)    {    matrix[i][j] = in.nextDouble();    }        Matrix A = new Matrix(matrix);    //A.print();        System.out.println("Input a m×n matrix...");        m = in.nextInt();    n = in.nextInt();        matrix = new double[m][n];        //System.out.println("m = " + matrix.length);    //System.out.println("n = " + matrix[0].length);        for(int i = 0; i < m; i++)    for(int j = 0; j < n; j++)    {    matrix[i][j] = in.nextDouble();    }        Matrix B = new Matrix(matrix);        //Matrix C = A.add(B);    //C.print();    //Matrix D = A.sub(B);    //D.print();    //Matrix E = A.mul(B);    //E.print();        System.out.println("1. A + b");System.out.println("2. A - B");System.out.println("3. A * B");int ch = 0;System.out.print("Choose your operation: ");try{BufferedReader br = new BufferedReader( new InputStreamReader(System.in) );ch = Integer.parseInt(br.readLine());}catch(IOException ex){}Matrix C = new Matrix();switch(ch){case 1:C = A.add(B);C.print();break;case 2:C = A.sub(B);C.print();break;case 3:C = A.mul(B);C.print();break;default:System.out.println("Choice Error!!");break;}    }        }