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 another method that returns the sum of all the elements in a specified row in a matrix using

the following header:

public static double sumRow( double [][] m, int rowIndex)

Write a test program that reads a 3-by-4 matrix and displays the sum of each column and sum of each row.

the result should print the sum of both the row and column respectively