@Test
public void testSummarize() {

  IntColumn c = IntColumn.indexColumn("t", 99, 1);
  IntColumn c2 = c.copy();
  c2.appendCell("");
  double c2Variance = c2.variance();
  double cVariance = StatUtils.variance(c.asDoubleArray());
  assertEquals(cVariance, c2Variance, 0.00001);
  assertEquals(StatUtils.sumLog(c.asDoubleArray()), c2.sumOfLogs(), 0.00001);
  assertEquals(StatUtils.sumSq(c.asDoubleArray()), c2.sumOfSquares(), 0.00001);
  assertEquals(StatUtils.geometricMean(c.asDoubleArray()), c2.geometricMean(), 0.00001);
  assertEquals(StatUtils.product(c.asDoubleArray()), c2.product(), 0.00001);
  assertEquals(StatUtils.populationVariance(c.asDoubleArray()), c2.populationVariance(), 0.00001);
  assertEquals(
      new DescriptiveStatistics(c.asDoubleArray()).getQuadraticMean(),
      c2.quadraticMean(),
      0.00001);
  assertEquals(
      new DescriptiveStatistics(c.asDoubleArray()).getStandardDeviation(),
      c2.standardDeviation(),
      0.00001);
  assertEquals(
      new DescriptiveStatistics(c.asDoubleArray()).getKurtosis(), c2.kurtosis(), 0.00001);
  assertEquals(
      new DescriptiveStatistics(c.asDoubleArray()).getSkewness(), c2.skewness(), 0.00001);
  assertEquals(StatUtils.variance(c.asDoubleArray()), c.variance(), 0.00001);
  assertEquals(StatUtils.sumLog(c.asDoubleArray()), c.sumOfLogs(), 0.00001);
  assertEquals(StatUtils.sumSq(c.asDoubleArray()), c.sumOfSquares(), 0.00001);
  assertEquals(StatUtils.geometricMean(c.asDoubleArray()), c.geometricMean(), 0.00001);
  assertEquals(StatUtils.product(c.asDoubleArray()), c.product(), 0.00001);
  assertEquals(StatUtils.populationVariance(c.asDoubleArray()), c.populationVariance(), 0.00001);
  assertEquals(
      new DescriptiveStatistics(c.asDoubleArray()).getQuadraticMean(),
      c.quadraticMean(),
      0.00001);
  assertEquals(
      new DescriptiveStatistics(c.asDoubleArray()).getStandardDeviation(),
      c.standardDeviation(),
      0.00001);
  assertEquals(new DescriptiveStatistics(c.asDoubleArray()).getKurtosis(), c.kurtosis(), 0.00001);
  assertEquals(new DescriptiveStatistics(c.asDoubleArray()).getSkewness(), c.skewness(), 0.00001);
}