matrices java code example

Example 1: multiply matrices java

public class Matrix {
  private double[][] multiply(double[][] matrixOne, double[][] matrixTwo) {
            assert matrixOne[0].length == matrixTwo.length: "width of matrix one must be equal to height of matrix two";
            double[][] product = new double[matrixOne.length][matrixTwo[0].length];
    		//fills output matrix with 0's
            for(short l = 0; l<matrixOne.length; l++) {
                for(short m = 0; m<matrixTwo[0].length; m++) {
                    product[l][m] = 0;
                }
            }
    		//takes the dot product of the rows and columns and adds them to output matrix
            for(short i = 0; i<matrixOne.length; i++) {
                for(short j = 0; j<matrixTwo[0].length; j++) {
                    for(short k = 0; k<matrixOne[0].length; k++) {
                        product[i][j] += matrixOne[i][k] * matrixTwo[k][j];
                    }
                }
            }
            return product;
        }
}

Example 2: java matrix

int [ ] [ ] scores = {   { 20, 18, 22, 20, 16 },
                                 { 18, 20, 18, 21, 20 },
                                 { 16, 18, 16, 20, 24 },
                                 {  25, 24, 22, 24, 25 }
                             };