import ccj.*; public class Vproduct { public static void main(String[] args) { double[][] m = new double[3][3]; m[0][0] = 1; m[0][1] = 2; m[0][2] = 3; m[1][0] = 0; m[1][1] = 1; m[1][2] = -1; m[2][0] = 2; m[2][1] = 1; m[2][2] = 0; double[] v = new double[3]; v[0] = 4; v[1] = 5; v[2] = 6; double[] r = vproduct(m, v); int i; for (i = 0; i < r.length; i++) System.out.println(r[i]); } public static double[] vproduct(double[][] a, double[] v) { double[] r = new double[a.length]; int i; for (i = 0; i < a.length; i++) { if (a[i].length != v.length) throw new IllegalArgumentException(); int k; double sum = 0; for (k = 0; k < v.length; k++) sum = sum + a[i][k] * v[k]; r[i] = sum; } return r; } }