JavaWorld: October 2015

We use 2D array to implement the matrices in java.

1) Matrix Addition In Java:

import java.util.Scanner;

public class MatrixAddition
{
public static void main(String[] args)
{
Scanner sc = new Scanner(System.in);

System.out.println("Enter The Number Of Rows");

int row = sc.nextInt();

System.out.println("Enter The Number Of Columns");

int cols = sc.nextInt();

int[][] matrix1 = new int[row][cols];

int[][] matrix2 = new int[row][cols];

int[][] sum = new int[row][cols];

System.out.println("Enter The Data For First Matrix :");

for (int i = 0; i < row; i++)
{
for (int j = 0; j < cols; j++)
{
matrix1[i][j] = sc.nextInt();
}
}

System.out.println("Enter The Data For Second Matrix :");

for (int i = 0; i < row; i++)
{
for (int j = 0; j < cols; j++)
{
matrix2[i][j] = sc.nextInt();
}
}

System.out.println("First Matrix = ");

for (int i = 0; i < row; i++)
{
for (int j = 0; j < cols; j++)
{
System.out.print(matrix1[i][j]+"\t");
}

System.out.println();
}

System.out.println("Second Matrix = ");

for (int i = 0; i < row; i++)
{
for (int j = 0; j < cols; j++)
{
System.out.print(matrix2[i][j]+"\t");
}

System.out.println();
}

System.out.println("Sum = ");

for (int i = 0; i < row; i++)
{
for (int j = 0; j < cols; j++)
{
sum[i][j] = matrix1[i][j] + matrix2[i][j];

System.out.print(sum[i][j]+"\t");
}

System.out.println();
}
}
}

2) Matrix Subtraction In Java :

import java.util.Scanner;

public class MatrixSubtraction
{
public static void main(String[] args)
{
Scanner sc = new Scanner(System.in);

System.out.println("Enter The Number Of Rows");

int row = sc.nextInt();

System.out.println("Enter The Number Of Columns");

int cols = sc.nextInt();

int[][] matrix1 = new int[row][cols];

int[][] matrix2 = new int[row][cols];

int[][] sub = new int[row][cols];

System.out.println("Enter The Data For First Matrix :");

for (int i = 0; i < row; i++)
{
for (int j = 0; j < cols; j++)
{
matrix1[i][j] = sc.nextInt();
}
}

System.out.println("Enter The Data For Second Matrix :");

for (int i = 0; i < row; i++)
{
for (int j = 0; j < cols; j++)
{
matrix2[i][j] = sc.nextInt();
}
}

System.out.println("First Matrix = ");

for (int i = 0; i < row; i++)
{
for (int j = 0; j < cols; j++)
{
System.out.print(matrix1[i][j]+"\t");
}

System.out.println();
}

System.out.println("Second Matrix = ");

for (int i = 0; i < row; i++)
{
for (int j = 0; j < cols; j++)
{
System.out.print(matrix2[i][j]+"\t");
}

System.out.println();
}

System.out.println("Subtraction = ");

for (int i = 0; i < row; i++)
{
for (int j = 0; j < cols; j++)
{
sub[i][j] = matrix1[i][j] - matrix2[i][j];

System.out.print(sub[i][j]+"\t");
}

System.out.println();
}
}
}

3) Matrix Multiplication In Java :

import java.util.Scanner;

public class MatrixMultiplication
{
public static void main(String[] args)
{
Scanner sc = new Scanner(System.in);

System.out.println("Enter The Number Of Rows In First Matrix");

int rowsInFirst = sc.nextInt();

System.out.println("Enter The Number Of Columns In First Matrix/Rows In Second Matrix");

int colsInFirstRowsInSecond = sc.nextInt();

System.out.println("Enter The Number Of Columns In Second Matrix");

int colsInSecond = sc.nextInt();

int[][] matrix1 = new int[rowsInFirst][colsInFirstRowsInSecond];

int[][] matrix2 = new int[colsInFirstRowsInSecond][colsInSecond];

int[][] product = new int[rowsInFirst][colsInSecond];

System.out.println("Enter The Data For First Matrix :");

for (int i = 0; i < rowsInFirst; i++)
{
for (int j = 0; j < colsInFirstRowsInSecond; j++)
{
matrix1[i][j] = sc.nextInt();
}
}

System.out.println("Enter The Data For Second Matrix :");

for (int i = 0; i < colsInFirstRowsInSecond; i++)
{
for (int j = 0; j < colsInSecond; j++)
{
matrix2[i][j] = sc.nextInt();
}
}

System.out.println("First Matrix = ");

for (int i = 0; i < rowsInFirst; i++)
{
for (int j = 0; j < colsInFirstRowsInSecond; j++)
{
System.out.print(matrix1[i][j]+"\t");
}

System.out.println();
}

System.out.println("Second Matrix = ");

for (int i = 0; i < colsInFirstRowsInSecond; i++)
{
for (int j = 0; j < colsInSecond; j++)
{
System.out.print(matrix2[i][j]+"\t");
}

System.out.println();
}

System.out.println("Product = ");

for (int i = 0; i < rowsInFirst; i++)
{
for (int j = 0; j < colsInSecond; j++)
{
for (int k = 0; k < colsInFirstRowsInSecond; k++)
{
product[i][j] += matrix1[i][k] * matrix2[k][j];
}
}
}

for (int i = 0; i < rowsInFirst; i++)
{
for (int j = 0; j < colsInSecond; j++)
{
System.out.print(product[i][j]+"\t");
}

System.out.println();
}
}
}

4) Transpose Of A Matrix

Transpose of a matrix is formed by turning all rows of a matrix into columns and columns into

rows.

import java.util.Scanner;

public class MatrixTranspose
{
public static void main(String[] args)
{
Scanner sc = new Scanner(System.in);

System.out.println("Enter The Number Of Rows");

int rows = sc.nextInt();

System.out.println("Enter The Number Of Columns");

int cols = sc.nextInt();

int[][] matrix = new int[rows][cols];

int[][] transpose = new int[cols][rows];

System.out.println("Enter The Data For Matrix :");

for (int i = 0; i < rows; i++)
{
for (int j = 0; j < cols; j++)
{
matrix[i][j] = sc.nextInt();
}
}

System.out.println("Your Matrix is :");

for (int i = 0; i < rows; i++)
{
for (int j = 0; j < cols; j++)
{
System.out.print(matrix[i][j]+" ");
}

System.out.println();
}

System.out.println("Transpose of Matrix is :");

for (int i = 0; i < rows; i++)
{
for (int j = 0; j < cols; j++)
{
transpose[j][i] = matrix[i][j];
}
}

for (int i = 0; i < cols; i++)
{
for (int j = 0; j < rows; j++)
{
System.out.print(transpose[i][j]+"\t");
}

System.out.println();
}
}
}

JavaWorld

Saturday, 10 October 2015

Matrix Operations In Java