Trusted answers to developer questions
How to check if a given matrix is a diagonal matrix
abhilash
What is a diagonal matrix?
A diagonal matrix is a square matrix in which all members are zero, except the major diagonal elements.
Example
| Dimension | Matrix |
|---|---|
| 2 x 2 | [[34, 0], [0, -4]] |
| 3 x 3 | [[4, 0, 0], [0, -1, 0], [0, 0, -3]] |
Algorithm
-
Start looping over the elements of the matrix.
-
For every element, check the following:
a. If the row number is equal to the column number, then it’s a diagonal element. Check if the value is not equal to
zero.b. If the row number is not equal to the column number, then it’s not a diagonal element. Check if the value is
zero.c. If any of the above conditions are
false, then the matrix is not a diagonal matrix, and the program returnsfalse.d. Otherwise, it returns
true, indicating that the matrix is a diagonal matrix.
Code
import java.util.Arrays;
public class Main {
private static void printMatrix(int[][] matrix){
for(int[] row: matrix){
System.out.println(Arrays.toString(row));
}
}
private static boolean checkDiagonalMatrix(int[][] matrix){
for(int i=0; i<matrix.length;i++)
for(int j=0; j<matrix[i].length;j++){
if((i == j && matrix[i][j] == 0) || (i != j && matrix[i][j] != 0)) return false;
}
return true;
}
private static void wrapper(int[][] matrix){
printMatrix(matrix);
if(checkDiagonalMatrix(matrix)) System.out.println("The matrix is a diagonal matrix");
else System.out.println("The matrix is not a diagonal matrix");
}
public static void main(String[] args){
int[][] matrix = {{4, -1},{15, -4}};
wrapper(matrix);
System.out.println("-------------");
int[][] matrix1 = {{4, 0},{0, -4}};
wrapper(matrix1);
}
}RELATED TAGS
matrix
datastructure
communitycreator
CONTRIBUTOR
abhilash
RELATED COURSES
View all Courses
Keep Exploring
Related Courses
