Examples with MeanVariance de.lmu.ifi.dbs.elki.math.MeanVariance used on opensource projects

Example 61 with MeanVariance

use of de.lmu.ifi.dbs.elki.math.MeanVariance in project elki by elki-project.

the class InstanceLogRankNormalizationTest method defaultParameters.

/**
 * Test with default parameters.
 */
@Test
public void defaultParameters() {
    String filename = UNITTEST + "normalization-test-1.csv";
    InstanceLogRankNormalization<DoubleVector> filter = new ELKIBuilder<>(InstanceLogRankNormalization.class).build();
    MultipleObjectsBundle bundle = readBundle(filename, filter);
    int dim = getFieldDimensionality(bundle, 0, TypeUtil.NUMBER_VECTOR_FIELD);
    // Compute the expected mean and variances..
    MeanVariance expected = new MeanVariance();
    for (int ii = 0; ii < dim; ii++) {
        expected.put(Math.log1p(ii / (double) (dim - 1)) * MathUtil.ONE_BY_LOG2);
    }
    // The smallest value (except for ties) must be mapped to 0, the largest to
    // 1. And (again, except for ties), the mean and variance must match above
    // expected values of a uniform distribution.
    MeanVarianceMinMax mms = new MeanVarianceMinMax();
    for (int row = 0; row < bundle.dataLength(); row++) {
        DoubleVector d = get(bundle, row, 0, DoubleVector.class);
        for (int col = 0; col < dim; col++) {
            mms.put(d.doubleValue(col));
        }
        assertEquals("Min value is not 0", 0., mms.getMin(), 0);
        assertEquals("Max value is not 1", 1., mms.getMax(), 0);
        assertEquals("Mean value is not as expected", expected.getMean(), mms.getMean(), 1e-14);
        assertEquals("Variance is not as expected", expected.getNaiveVariance(), mms.getNaiveVariance(), 1e-14);
        mms.reset();
    }
}