Java program to find trace of a matrix

Let’s learn java program to find trace of a matrix.

Java program to find trace of a matrix

Trace of a matrix is nothing but sum of diagonal elements. For example consider square matrix m x m,

1 2 3
4 5 6
7 8 9

Trace of a matrix is: 1 + 5 + 9 = 15

Here’s the java program.

import java.util.Scanner;
public class TraceMatrixDemo 
{
   public static void main(String[] args) 
   {
      int[][] arrInput = new int[10][10];
      int a, b;
      double total = 0;
      System.out.println("Please enter total rows and columns: ");
      Scanner sc = new Scanner(System.in);
      int row = sc.nextInt();
      int column = sc.nextInt();
      System.out.println("Please enter matrix: ");
      for(a = 0; a < row; a++)
      {
         for(b = 0; b < column; b++) 
         {
            arrInput[a][b] = sc.nextInt();
            System.out.print(" ");
         }
      }
      System.out.println("Entered matrix is: ");
      for(a = 0; a < row; a++)
      {
         for(b = 0; b < column; b++)
         {
            System.out.println(arrInput[a][b] + " ");
         }
         System.out.println(" ");
      }
      System.out.println("Trace of a matrix: ");
      for(a = 0; a < row; a++)
      {  
         for(b = 0; b < column; b++)
         {
            if(a == b)
            {
               total = total + (arrInput[a][b]);
            }
         }
      }
      System.out.println(total);
      sc.close();
   }
}


Output:

Please enter total rows and columns:
3
3
Please enter matrix:
2
4
6
8
1
3
5
7
9
Entered matrix is:
2 4 6
8 1 3
5 7 9
Trace of a matrix:
12.0


Also read – strings in java