Java Program to Represent Linear Equations in Matrix Form

Last Updated : 12 Apr, 2023

Let's look at the System of Linear Equation with the help of an example:

The input of coefficients and variables is taken into play for consideration.

The scanner package should be imported into the program in order to use the object of the Scanner class to take the input from the user.
The array will be initialized to store the variables of the equations.
The coefficients of the variables will be taken from the user with the help of the object of the Scanner class.
The equations will then converted into the form of a matrix with the help of a loop.

Two examples are laid off:

3 variable linear equations in matrix form.
N variable linear equations in matrix form.

Illustration: Considering the most used practical linear equation used in mathematics, that is 3 variable linear equations.

Input: ax + by + cz = d

Output - 1 2 3 x = 10
     5 1 3 y = 12
      7 4 2 z = 20

Example 1: Java Program for 3 variable linear equations in matrix form.

Java

// Java Program to Represent Linear Equations in Matrix Form

// Importing Scanner class
// to take input from user
import java.util.Scanner;

public class GFG {
  
    // Mai driver method
    public static void main(String args[])
    {
        // Display message for better readability
        System.out.println(
            "******** 3 variable linear equation ********");

        // 3 variables of the linear equation
        char[] variable = { 'x', 'y', 'z' };

        // Creating Scanner class object
        Scanner sc = new Scanner(System.in);

        // Display message for asking user to enter input
        System.out.println(
            "Enter the coefficients of 3 variable");
        System.out.println(
            "Enter in the format shown below");
        System.out.println("ax + by + cz = d");

        // For 3*3 matrix or in other words
        // Dealing with linear equations of 3 coefficients

        // Input of coefficients from user
        int[][] matrix = new int[3][3];
        int[][] constt = new int[3][1];

        // Outer loop for iterating rows
        for (int i = 0; i < 3; i++) {
            // Inner loop for iterating columns
            for (int j = 0; j < 3; j++) {

                // Reading values from usr and
                // entering in the matrix form
                matrix[i][j] = sc.nextInt();
            }

            // One row input is over by now
            constt[i][0] = sc.nextInt();
        }

        // The linear equations in the form of matrix

        // Display message
        System.out.println(
            "Matrix representation of above linear equations is: ");

        // Outer loop for iterating rows
        for (int i = 0; i < 3; i++) {

            // Inner loop for iterating columns
            for (int j = 0; j < 3; j++) {

                // Printing matrix corresponding
                // linear equation
                System.out.print(" " + matrix[i][j]);
            }

            System.out.print("  " + variable[i]);
            System.out.print("  =  " + constt[i][0]);
            System.out.println();
        }

        // Close the stream and release the resources
        sc.close();
    }
}

Output:

Now, getting it generic for any value of N: “n-variable linear equation”

Illustration:

Input: ax + by + cz + ... = d

Output: 1 2 3 x = 10
        5 1 3 y = 12
     7 4 2 z = 20
     ...
     ...

Example 2: Java Program for N variable linear equations in matrix form.

Java

import java.util.Scanner;

public class Linear_Equations_n {
    public static void main(String args[])
    {
        System.out.println(
            "******** n variable linear equation ********");
        // Initializing the variables
        char[] variable
            = { 'a', 'b', 'c', 'x', 'y', 'z', 'w' };
        System.out.println("Enter the number of variables");
        Scanner sc = new Scanner(System.in);
        int num = sc.nextInt();
        System.out.println(
            "Enter the coefficients variable");
        System.out.println(
            "Enter in the format shown below");
        System.out.println("ax + by + cz + ... = d");
      
        // Input of coefficients from user
        int[][] matrix = new int[num][num];
        int[][] constt = new int[num][1];
        for (int i = 0; i < num; i++) {
            for (int j = 0; j < num; j++) {
                matrix[i][j] = sc.nextInt();
            }
            constt[i][0] = sc.nextInt();
        }
        // Representation of linear equations in form of
        // matrix
        System.out.println(
            "Matrix representation of above linear equations is: ");
        for (int i = 0; i < num; i++) {
            for (int j = 0; j < num; j++) {
                System.out.print(" " + matrix[i][j]);
            }
            System.out.print("  " + variable[i]);
            System.out.print("  =  " + constt[i][0]);
            System.out.println();
        }
        sc.close();
    }
}