Question

use java please

Exercise 3 Sum the Major Diagonal of a Matrix Complete exercise 8.2 on page 308 of the textbook. Note there are some modifications to the exercise in the steps below. 1. Create a new NetBeans project called Ex3SumDiagonal. 2. Generate a 4x4 array and fill with random doubles between 1 and 20. Display your array. Hint: The printf() method can be used to limit the decimal places displayed. The code below can be used to generate a double within a given range. val - (MIN VAL + ((MAXVAL - MIN VAL). Ind.nextDouble())); 3. Code a user defined method that sums all the numbers in the major diagonal in an n'n matrix. The major diagonal runs from top left to bottom right. public static double sumMajor Diagonal (double[] [] m) double sum - 0; return sum; 4. Test your method using the array you generated in step 2 and display the result. For testing purposes, you may generate the hard-coded array shown in the book and verify your output matches the book. Output - Ex3SumDiagonal (run) X 7.17 9.72 12.17 4.99 5.67 1.13 3.46 1.06 11.49 16.21 9.15 4.50 19.97 15.54 17.17 8.52 The sum of the major diagonal is 25.97 BUILD SUCCESSFUL total time: seconds)

Answer 1

package Ex3SumDiagonal;

import java.util.Random;

public class Ex3SumDiagonal {

    public static double sumMajorDiagonal(double[][] m) {
        double sum = 0;
        for (int i = 0; i < m.length; i++) {
            sum += m[i][i];
        }
        return sum;
    }

    public static void main(String[] args) {
        Random random = new Random();
        final int SIZE = 4;
        double[][] m = new double[SIZE][SIZE];
        for (int i = 0; i < SIZE; i++) {
            for (int j = 0; j < SIZE; j++) {
                m[i][j] = 1 + random.nextDouble() * 19;
            }
        }

        for (int i = 0; i < SIZE; i++) {
            for (int j = 0; j < SIZE; j++) {
                System.out.printf("%.2f ", m[i][j]);
            }
            System.out.println();
        }

        System.out.printf("\nThe sum of the major diagonal is %.2f\n", sumMajorDiagonal(m));
    }
}

13.95 13.15 9.50 6.25 19.46 1.55 11.62 14.14 17.53 12.66 2.80 8.39 7.82 13.35 4.60 3.72 The sum of the major diagonal is 22.01,