Determinant of matrix in java

Answer 1

/*This function will return the determinant of any two dimensional matrix. For this particular function a two dimensional double matrix needs to be passed as arguments - Avishek Ghosh*/

public double determinant(double[][] mat) {

double result = 0;

if(mat.length 2) {

result = mat[0][0] * mat[1][1] - mat[0][1] * mat[1][0];

return result;

}

for(int i = 0; i < mat[0].length; i++) {

double temp[][] = new double[mat.length - 1][mat[0].length - 1];

for(int j = 1; j < mat.length; j++) {

System.arraycopy(mat[j], 0, temp[j-1], 0, i);

System.arraycopy(mat[j], i+1, temp[j-1], i, mat[0].length-i-1);

}

result += mat[0][i] * Math.pow(-1, i) * determinant(temp);

}

return result;

}