@Test
public void testConstructors() {
VariableStatistics vs1 = new VariableStatistics();
Assert.assertEquals(vs1.getCount(), 0);
Assert.assertEquals(vs1.getSum(), 0, TOLERANCE);
Assert.assertEquals(vs1.getSumSquares(), 0, TOLERANCE);
VariableStatistics set1 = getVS1();
VariableStatistics set2 = getVS1();
Assert.assertTrue(set1.equivalent(set2));
Assert.assertFalse(set1.equivalent(vs1));
Assert.assertEquals(set1.getCount(), DATA_SET_SIZE);
Assert.assertEquals(set1.getSum(), 30, TOLERANCE);
Assert.assertEquals(set1.getSumSquares(), 166, TOLERANCE);
Assert.assertEquals(set1.getMean(), 5, TOLERANCE);
double stdev = set1.getStandardDeviation();
Assert.assertEquals(stdev, 1.63299, TOLERANCE);
set2 = getVS2();
Assert.assertEquals(set2.getCount(), DATA_SET_SIZE);
Assert.assertEquals(set2.getSum(), 30, TOLERANCE);
Assert.assertEquals(set2.getSumSquares(), 216, TOLERANCE);
Assert.assertEquals(set2.getMean(), 5, TOLERANCE);
stdev = set2.getStandardDeviation();
Assert.assertEquals(stdev, 3.3166, TOLERANCE);
}
@Test
public void testAdd() {
VariableStatistics set1 = getVS1();
VariableStatistics set2 = getVS2();
set1.add(set2);
Assert.assertEquals(set1.getCount(), 2 * DATA_SET_SIZE);
Assert.assertEquals(set1.getSum(), 60, TOLERANCE);
Assert.assertEquals(set1.getSumSquares(), 216 + 166, TOLERANCE);
Assert.assertEquals(set1.getMean(), 5, TOLERANCE);
double stdev = set1.getStandardDeviation();
Assert.assertEquals(stdev, 2.61406452, TOLERANCE);
VariableStatistics setx = new VariableStatistics(set2, set2, set2, set2);
Assert.assertEquals(setx.getCount(), 4 * DATA_SET_SIZE);
Assert.assertEquals(setx.getSum(), 4 * 30, TOLERANCE);
Assert.assertEquals(setx.getSumSquares(), 4 * 216, TOLERANCE);
Assert.assertEquals(setx.getMean(), 5, TOLERANCE);
stdev = setx.getStandardDeviation();
Assert.assertEquals(stdev, 3.3166, TOLERANCE);
}