(Column sorting) Implement the following method to sort the columns in a twodimensional array. A new array is returned and the original array is intact

/*********************************************************************************
* (Column sorting) Implement the following method to sort the columns in a       *
* twodimensional array. A new array is returned and the original array is intact.*
*                                                                                *
* public static double[][] sortColumns(double[][] m)                             *
*                                                                                *
* Write a test program that prompts the user to enter a 3 * 3 matrix of double   *
* values and displays a new column-sorted matrix. Here is a sample run:          *
*********************************************************************************/
import java.util.Scanner;

public class Exercise_08_27 {
	/** Main method */
	public static void main(String[] args) {
		// Get a 3 x 3 matrix of double values from user input
		double[][] matrix = getMatrix();

		// Get a new sorted matrix
		double[][] sortedMatrix = sortColumns(matrix);

		// Display new sorted matrix
		System.out.println("\nThe column-sorted array is");
		for (int i = 0; i < sortedMatrix.length; i++) {
			for (int j = 0; j < sortedMatrix.length; j++) {
				System.out.print(sortedMatrix[i][j] + " ");
			}
			System.out.println();
		}
	}

	/** getMatrix prompts the user to enter a 3 x 3 
	    matrix of double values then returns it */
	public static double[][] getMatrix() {
		Scanner input = new Scanner(System.in);
		double[][] m = new double[3][3];

		System.out.println("Enter a 3-by-3 matrix row by row:");
		for (int i = 0; i < m.length; i++) {
			for (int j = 0; j < m[i].length; j++) {
				m[i][j] = input.nextDouble();
			}
		}
		return m;
	}

	/** sortColums return a new column-sorted  
	    array leaving original array intact */
	public static double[][] sortColumns(double[][] m)  {
		// Create a new 3-by-3 matrix
		double[][] s = new double[m.length][m[0].length];
		
		// Copy elements to new matrix
		copyMatrix(m, s);

		// Sort new matrix by column
		for (int col = 0; col < s.length; col++) {
			for (int row = 0; row < s.length - 1; row++) {
				double min = s[row][col];
				int index = row;
				for (int j = row + 1; j < s.length; j++) {
					if (min > s[j][col]) {
						min = s[j][col];
						index = j;
					}
				}
				if (index != row) {
					s[index][col] = s[row][col];
					s[row][col] = min;
				}
			}
		}
		return s;
	}

	/** copyMatrix copies all the elements in the original matrix to the copy */ 
	public static void copyMatrix(double[][] original, double[][] copy) {
		for (int i = 0; i < original.length; i++) {
			for (int j = 0; j < original[i].length; j++) {
				copy[i][j] = original[i][j];
			}
		}
	}
}