Write the following in Netbeans IDE 81 Write a method that r

Write the following in Netbeans IDE 8.1

Write a method that returns the sum of all the elements in a specified column in a matrix using the following header: public static double sumColumn(double[][] m, int columnIndex) Write a test program that reads a 3-by-4 matrix and displays the sum of each column. Here is a sample run: Enter a 3-by-4 matrix row by row: 1.5 2 3 4 5.5 6 7 8 9.5 1 3 1 Sum of the elements at column 0 is 16.5 Sum of the elements at column 1 is 9.0 Sum of the elements at column 2 is 13.0 Sum of the elements at column 3 is 13.0

Solution

ArrayColumnSum.java

import java.util.Scanner;

public class ArrayColumnSum {

   public static void main(String[] args) {
       double d[][] = new double[3][4];
       Scanner scan = new Scanner(System.in);
       System.out.println(\"Enter a 3-by-4 matrix row by row: \");
       for(int i=0; i<d.length; i++){
           for(int j=0; j<d[i].length; j++){
               d[i][j] = scan.nextDouble();
           }
       }
       for(int i=0; i<4; i++){
           System.out.println(\"Sum of the elements at column \"+i+\" is \"+sumColumn(d,i));
       }
   }
   public static double sumColumn(double[][] m, int columnIndex){
       double sum = 0;
       for(int i=0; i<m.length;i++){
           sum = sum + m[i][columnIndex];
       }
       return sum;
   }

}

Output:

Enter a 3-by-4 matrix row by row:
1.5 2 3 4
5.5 6 7 8
9.5 1 3 1
Sum of the elements at column 0 is 16.5
Sum of the elements at column 1 is 9.0
Sum of the elements at column 2 is 13.0
Sum of the elements at column 3 is 13.0