@Test
public void testCovariance() {
DataFrame df = context.table("testData2");
Double result = df.stat().cov("a", "b");
Assert.assertTrue(Math.abs(result) < 1.0e-6);
}
@Test
public void testCorrelation() {
DataFrame df = context.table("testData2");
Double pearsonCorr = df.stat().corr("a", "b", "pearson");
Assert.assertTrue(Math.abs(pearsonCorr) < 1.0e-6);
}