Question

For the program described below, document your code well.

Use descriptive identifier names. Use spaces and indentation to improve readability. Include a beginning comment block as well as explanatory comments throughout. In the beginning comment block, add your name, program name, date written, program description. The description briefly describes what the program does. Include a comment at the beginning of each method to describe what the method does.

Write a program to perform operations on square matrices (i.e. equal number of rows and columns). Both matrices should have the same number of rows and columns. The user should be asked to enter the number of rows/columns of the matrix. Use 2-D arrays to represent the matrices. Your program will fill the arrays with random numbers between 1 and 10 Option 1 The program should do the following in order Fill the arrays Print the matrices Transpose first matrix Transpose second matrix Print the matrices Multiply the matrices Print the result . You should have methods for at least the following: fillArray – accepts an array and fills it with random numbers transposeArray – accepts an array and transposes it i.e. interchanges rows and columns printArray – a cepts an array and prints it multiply – accepts two arrays, multiplies them and returns the result. Use JOptionPane to interact with the user except when printing the matrices

The program should do the following in order

Fill the arrays

Print the matrices

Transpose first matrix

Transpose second

matrix Print the matrices

Multiply the matrices

Print the result .

You should have methods for at least the following: fillArray – accepts an array and fills it with random numbers

transposeArray – accepts an array and transposes it i.e. interchanges rows and columns

printArray – a cepts an array and prints it

multiply – accepts two arrays, multiplies them and returns the result.

Use JOptionPane to interact with the user except when printing the matrices

Answer 1

Hi,

Please find the java program below:

///////////////////////////

import java.util.Random;
import java.util.Scanner;

/****************************************************
*
* @author
* Name:
* Program Name:
* Date:
*
***************************************************
*Program Description:
*Program to perform operations on square matrices
*
****************************************************/

public class SquareMatrixOperations {

   public static void main(String[] args) {
       int rowsOrColumns;
       Scanner keyboard = new Scanner(System.in);
       System.out.println("Enter the number of rows/columns of the matrix:");
       rowsOrColumns = keyboard.nextInt();
       int squareMatrix[][] = new int[rowsOrColumns][rowsOrColumns];
       // Fill the square matrix with random numbers
       fillArray(squareMatrix,rowsOrColumns);
       // print the square matrix
       System.out.println("Square Matrix:= ");
       printArray(squareMatrix,rowsOrColumns);
       // transpose the square matrix
       int[][] transposedMatrix= transposeArray(squareMatrix,rowsOrColumns);
       // print the transposed square matrix
       System.out.println("Transposed Matrix:= ");
       printArray(transposedMatrix,rowsOrColumns);
      
       int[][] multipledMatrix=multiply(squareMatrix,transposedMatrix,rowsOrColumns);
       System.out.println("Multiplied Matrix:= ");
       printArray(multipledMatrix,rowsOrColumns);
      
       keyboard.close();
   }

   /****************************************
   * Fills the array with random numbers
   * @param array
   * @param n
   *****************************************/
   public static void fillArray(int[][] array,int n) {
       Random r = new Random();
       for (int i = 0; i < n; i++) {
           for (int j = 0; j < n; j++) {
               //random numbers between 1 to 10
               array[i][j] = r.nextInt(10) + 1;
           }
       }
   }

   /****************************************
   * transposes the Array
   * @param array
   * @param n
   * return transposed matrix
   *****************************************/
   public static int[][] transposeArray(int[][] array,int n) {
       int transpose[][] = new int[n][n];
       for (int i = 0; i < n; i++) {
           for (int j = 0; j < n; j++) {
               //transpose the array
               transpose[i][j] = array[j][i];
           }
       }
       return transpose;
   }

   /****************************************
   * prints the the Array
   * @param array a
   * @param array b
   * @param n
   *****************************************/
   public static int[][] multiply(int[][] a, int[][] b,int n) {
       int c[][]=new int[n][n];

       for(int i=0;i<n;i++){
           for(int j=0;j<n;j++){
               c[i][j]=0;  
               for(int k=0;k<n;k++)  
               {  
                   c[i][j]+=a[i][k]*b[k][j];  
               }

           }
       }
       return c;
   }
  
   /****************************************
   * prints the the Array
   * @param array
   * @param n
   *****************************************/
   public static void printArray(int[][] array,int n) {

       for (int i = 0; i < n; i++) {
           for (int j = 0; j < n; j++) {
               //print the array element
               System.out.print(array[i][j] + "   ");
           }
           //print new line for new row
           System.out.println();
       }
       System.out.println("--------------------------");
   }
}

//////////////////////////

Sample output
Enter the number of rows/columns of the matrix:
2
Square Matrix:=
3   7
4   3
--------------------------
Transposed Matrix:=
3   4
7   3
--------------------------
Multiplied Matrix:=
58   33
33   25
--------------------------

Screenshot:

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Hope this helps.

Thanks.