TwoingStatisticTest.java

package hex.singlenoderf;

import org.junit.Test;
import org.junit.Assert;

public class TwoingStatisticTest {

  @Test
  public void twoingTest() {
    // basic test cases to check twoing computation
    int[] dd_l = {4,0,0,1};
    int[] dd_r = {0,3,2,0};
    double result = twoing(dd_l, 5, dd_r, 5);
    Assert.assertTrue(Math.abs(result - 4.0) < 1e-10);

    dd_l[0] = 4; dd_l[1] = 3; dd_l[2] = 2; dd_l[3] = 0;
    dd_r[0] = 0; dd_r[1] = 0; dd_r[2] = 0; dd_r[3] = 1;
    result = twoing(dd_l, 9, dd_r, 1);
    Assert.assertTrue(Math.abs(result - 4.0) < 1e-10);

    dd_l[0] = 4; dd_l[1] = 3; dd_l[2] = 1; dd_l[3] = 0;
    dd_r[0] = 0; dd_r[1] = 0; dd_r[2] = 1; dd_r[3] = 1;
    result = twoing(dd_l, 8, dd_r, 2);
    Assert.assertTrue(Math.abs(result - 3.0625) < 1e-10);

    dd_l[0] = 999; dd_l[1] = 1000005; dd_l[2] = 3009; dd_l[3] = 1;
    dd_r[0] = 999; dd_r[1] = 1000005; dd_r[2] = 3009; dd_r[3] = 1;
    result = twoing(dd_l, 999+1000005+3009+1, dd_r, 999+1000005+3009+1);
    Assert.assertTrue(Math.abs(result - 0.0) < 1e-10);
  }

  private double twoing(int[] dd_l, int sum_l, int[] dd_r, int sum_r ) {
    double result = 0.0;
    double sd_l = (double)sum_l;
    double sd_r = (double)sum_r;
    for (int i = 0; i < dd_l.length; i++) {
      double tmp = Math.abs(((double)dd_l[i])/sd_l - ((double)dd_r[i])/sd_r);
      result = result + tmp;
    }
    result = result * result;
    return result;
  }
}