Java Program to Find Inverse of a Matrix
Here you will get java program to find inverse of a matrix of order 2×2 and 3×3.
We can find inverse of a matrix in following way.
- First find the determinant of matrix.
- Calculate adjoint of matrix.
- Finally divide adjoint of matrix by determinant.
Below I have shared program to find inverse of 2×2 and 3×3 matrix.
Java Program to Find Inverse of a Matrix
2×2 Matrix
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 |
import java.util.Scanner; public class JavaMatrixInverse { public static void main(String args[]) { int i, j; float det, temp; float mat[][] = new float[2][2]; Scanner sc = new Scanner(System.in); System.out.println("Enter elements of matrix row wise:"); for(i = 0; i < 2; ++i) for(j = 0; j < 2; ++j) mat[i][j] = sc.nextFloat(); det = (mat[0][0] * mat[1][1]) - (mat[0][1] * mat[1][0]); System.out.println("\ndeterminant = " + det); temp = mat[0][0]; mat[0][0] = mat[1][1]; mat[1][1] = temp; mat[0][1] = - mat[0][1]; mat[1][0] = - mat[1][0]; System.out.println("\nInverse of matrix is:"); for(i = 0; i < 2; ++i) { for(j = 0; j < 2; ++j) System.out.print((mat[i][j]/det) + " "); System.out.print("\n"); } } } |
Output
Enter elements of matrix row wise:
4 7
2 6
determinant = 10.0
Inverse of matrix is:
0.6 -0.7
-0.2 0.4
3×3 Matrix
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 |
import java.util.Scanner; public class JavaMatrixInverse { public static void main(String args[]) { int i, j; float det = 0; float mat[][] = new float[3][3]; Scanner sc = new Scanner(System.in); System.out.println("Enter elements of matrix row wise:"); for(i = 0; i < 3; ++i) for(j = 0; j < 3; ++j) mat[i][j] = sc.nextFloat(); for(i = 0; i < 3; i++) det = det + (mat[0][i] * (mat[1][(i+1)%3] * mat[2][(i+2)%3] - mat[1][(i+2)%3] * mat[2][(i+1)%3])); System.out.println("\ndeterminant = " + det); System.out.println("\nInverse of matrix is:"); for(i = 0; i < 3; ++i) { for(j = 0; j < 3; ++j) System.out.print((((mat[(j+1)%3][(i+1)%3] * mat[(j+2)%3][(i+2)%3]) - (mat[(j+1)%3][(i+2)%3] * mat[(j+2)%3][(i+1)%3]))/ det) + " "); System.out.print("\n"); } } } |
Output
Enter elements of matrix row wise:
1 2 3
0 1 4
5 6 0
determinant = 1.0
Inverse of matrix is:
-24.0 18.0 5.0
20.0 -15.0 -4.0
-5.0 4.0 1.0
Comment below if you have any queries related to above program to find inverse of matrix in java.
10:50 am
is it possible that you write a generic program for the inverse of a matrix?
12:28 pm
Hmmmmm.
I may try to make an inverse. Check the loop – it has %3 (modulo 3) many places. And it has loops going up to and not including 3. This may be a part of it. Furthermore we may need to see how matrix multiplication is done with 3, 4 and 5 dimensions – then that may give a clue..
One day … Hmmmm
12:23 pm
Thank you so much for providing such software snippets. It is a great help for us who are maybe not THAAAAAT super experts in mathematics.
If you on the other hand, one day, need assistance on algorithms, feel welcome.