@Test
public void testSummaryConsistency() {
final DescriptiveStatistics dstats = new DescriptiveStatistics();
final SummaryStatistics sstats = new SummaryStatistics();
final int windowSize = 5;
dstats.setWindowSize(windowSize);
final double tol = 1E-12;
for (int i = 0; i < 20; i++) {
dstats.addValue(i);
sstats.clear();
double[] values = dstats.getValues();
for (int j = 0; j < values.length; j++) {
sstats.addValue(values[j]);
}
TestUtils.assertEquals(dstats.getMean(), sstats.getMean(), tol);
TestUtils.assertEquals(new Mean().evaluate(values), dstats.getMean(), tol);
TestUtils.assertEquals(dstats.getMax(), sstats.getMax(), tol);
TestUtils.assertEquals(new Max().evaluate(values), dstats.getMax(), tol);
TestUtils.assertEquals(dstats.getGeometricMean(), sstats.getGeometricMean(), tol);
TestUtils.assertEquals(new GeometricMean().evaluate(values), dstats.getGeometricMean(), tol);
TestUtils.assertEquals(dstats.getMin(), sstats.getMin(), tol);
TestUtils.assertEquals(new Min().evaluate(values), dstats.getMin(), tol);
TestUtils.assertEquals(dstats.getStandardDeviation(), sstats.getStandardDeviation(), tol);
TestUtils.assertEquals(dstats.getVariance(), sstats.getVariance(), tol);
TestUtils.assertEquals(new Variance().evaluate(values), dstats.getVariance(), tol);
TestUtils.assertEquals(dstats.getSum(), sstats.getSum(), tol);
TestUtils.assertEquals(new Sum().evaluate(values), dstats.getSum(), tol);
TestUtils.assertEquals(dstats.getSumsq(), sstats.getSumsq(), tol);
TestUtils.assertEquals(new SumOfSquares().evaluate(values), dstats.getSumsq(), tol);
TestUtils.assertEquals(dstats.getPopulationVariance(), sstats.getPopulationVariance(), tol);
TestUtils.assertEquals(
new Variance(false).evaluate(values), dstats.getPopulationVariance(), tol);
}
}
@Test
public void testShuffledStatistics() {
// the purpose of this test is only to check the get/set methods
// we are aware shuffling statistics like this is really not
// something sensible to do in production ...
DescriptiveStatistics reference = createDescriptiveStatistics();
DescriptiveStatistics shuffled = createDescriptiveStatistics();
UnivariateStatistic tmp = shuffled.getGeometricMeanImpl();
shuffled.setGeometricMeanImpl(shuffled.getMeanImpl());
shuffled.setMeanImpl(shuffled.getKurtosisImpl());
shuffled.setKurtosisImpl(shuffled.getSkewnessImpl());
shuffled.setSkewnessImpl(shuffled.getVarianceImpl());
shuffled.setVarianceImpl(shuffled.getMaxImpl());
shuffled.setMaxImpl(shuffled.getMinImpl());
shuffled.setMinImpl(shuffled.getSumImpl());
shuffled.setSumImpl(shuffled.getSumsqImpl());
shuffled.setSumsqImpl(tmp);
for (int i = 100; i > 0; --i) {
reference.addValue(i);
shuffled.addValue(i);
}
Assert.assertEquals(reference.getMean(), shuffled.getGeometricMean(), 1.0e-10);
Assert.assertEquals(reference.getKurtosis(), shuffled.getMean(), 1.0e-10);
Assert.assertEquals(reference.getSkewness(), shuffled.getKurtosis(), 1.0e-10);
Assert.assertEquals(reference.getVariance(), shuffled.getSkewness(), 1.0e-10);
Assert.assertEquals(reference.getMax(), shuffled.getVariance(), 1.0e-10);
Assert.assertEquals(reference.getMin(), shuffled.getMax(), 1.0e-10);
Assert.assertEquals(reference.getSum(), shuffled.getMin(), 1.0e-10);
Assert.assertEquals(reference.getSumsq(), shuffled.getSum(), 1.0e-10);
Assert.assertEquals(reference.getGeometricMean(), shuffled.getSumsq(), 1.0e-10);
}