Java Code Examples for org.apache.commons.math3.distribution.MultivariateNormalDistribution#getCovariances()

The following examples show how to use org.apache.commons.math3.distribution.MultivariateNormalDistribution#getCovariances() . You can vote up the ones you like or vote down the ones you don't like, and go to the original project or source file by following the links above each example. You may check out the related API usage on the sidebar.

Example 1

Source File: GaussianTest.java From macrobase with Apache License 2.0

5 votes

@Test
public void testMahalanobis() {
    MultivariateNormalDistribution mvNormal = getSample3dNormal();
    Gaussian gaussian = new Gaussian(mvNormal.getMeans(), mvNormal.getCovariances());

    int N = 100000;
    int k = 3;
    double[][] testData = new double[N][k];
    for (int i = 0; i < N; i++) {
        testData[i] = mvNormal.sample();
    }

    double[] mScores = new double[N];
    long startTime = System.currentTimeMillis();
    for (int i = 0; i < N; i++) {
        mScores[i] = gaussian.mahalanobis(testData[i]);
    }
    long endTime = System.currentTimeMillis();
    log.debug("Mahalobis distance on {} in {}", N, endTime-startTime);

    double[] dScores = new double[N];
    startTime = System.currentTimeMillis();
    for (int i = 0; i < N; i++) {
        dScores[i] = -Math.log(mvNormal.density(testData[i]));
    }
    endTime = System.currentTimeMillis();
    log.debug("LogPDF on {} in {}", N, endTime-startTime);

    // Check that mahalonbis distance has same relative magnitude as -log(pdf)
    for (int i = 1; i < N; i++) {
        assertEquals(mScores[i] > mScores[i-1], dScores[i] > dScores[i-1]);
    }
}

Example 2

Source File: MultivariateNormalMixtureExpectationMaximizationTest.java From astor with GNU General Public License v2.0

4 votes

@Test
public void testFit() {
    // Test that the loglikelihood, weights, and models are determined and
    // fitted correctly
    final double[][] data = getTestSamples();
    final double correctLogLikelihood = -4.292431006791994;
    final double[] correctWeights = new double[] { 0.2962324189652912, 0.7037675810347089 };
    
    final double[][] correctMeans = new double[][]{
        {-1.4213112715121132, 1.6924690505757753},
        {4.213612224374709, 7.975621325853645}
    };
    
    final RealMatrix[] correctCovMats = new Array2DRowRealMatrix[2];
    correctCovMats[0] = new Array2DRowRealMatrix(new double[][] {
        { 1.739356907285747, -0.5867644251487614 },
        { -0.5867644251487614, 1.0232932029324642 } }
            );
    correctCovMats[1] = new Array2DRowRealMatrix(new double[][] {
        { 4.245384898007161, 2.5797798966382155 },
        { 2.5797798966382155, 3.9200272522448367 } });
    
    final MultivariateNormalDistribution[] correctMVNs = new MultivariateNormalDistribution[2];
    correctMVNs[0] = new MultivariateNormalDistribution(correctMeans[0], correctCovMats[0].getData());
    correctMVNs[1] = new MultivariateNormalDistribution(correctMeans[1], correctCovMats[1].getData());

    MultivariateNormalMixtureExpectationMaximization fitter
        = new MultivariateNormalMixtureExpectationMaximization(data);

    MixtureMultivariateNormalDistribution initialMix
        = MultivariateNormalMixtureExpectationMaximization.estimate(data, 2);
    fitter.fit(initialMix);
    MixtureMultivariateNormalDistribution fittedMix = fitter.getFittedModel();
    List<Pair<Double, MultivariateNormalDistribution>> components = fittedMix.getComponents();

    Assert.assertEquals(correctLogLikelihood,
                        fitter.getLogLikelihood(),
                        Math.ulp(1d));

    int i = 0;
    for (Pair<Double, MultivariateNormalDistribution> component : components) {
        final double weight = component.getFirst();
        final MultivariateNormalDistribution mvn = component.getSecond();
        final double[] mean = mvn.getMeans();
        final RealMatrix covMat = mvn.getCovariances();
        Assert.assertEquals(correctWeights[i], weight, Math.ulp(1d));
        Assert.assertTrue(Arrays.equals(correctMeans[i], mean));
        Assert.assertEquals(correctCovMats[i], covMat);
        i++;
    }
}

Example 3

Source File: MultivariateNormalMixtureExpectationMaximizationTest.java From astor with GNU General Public License v2.0

4 votes

@Test
public void testFit() {
    // Test that the loglikelihood, weights, and models are determined and
    // fitted correctly
    final double[][] data = getTestSamples();
    final double correctLogLikelihood = -4.292431006791994;
    final double[] correctWeights = new double[] { 0.2962324189652912, 0.7037675810347089 };
    
    final double[][] correctMeans = new double[][]{
        {-1.4213112715121132, 1.6924690505757753},
        {4.213612224374709, 7.975621325853645}
    };
    
    final RealMatrix[] correctCovMats = new Array2DRowRealMatrix[2];
    correctCovMats[0] = new Array2DRowRealMatrix(new double[][] {
        { 1.739356907285747, -0.5867644251487614 },
        { -0.5867644251487614, 1.0232932029324642 } }
            );
    correctCovMats[1] = new Array2DRowRealMatrix(new double[][] {
        { 4.245384898007161, 2.5797798966382155 },
        { 2.5797798966382155, 3.9200272522448367 } });
    
    final MultivariateNormalDistribution[] correctMVNs = new MultivariateNormalDistribution[2];
    correctMVNs[0] = new MultivariateNormalDistribution(correctMeans[0], correctCovMats[0].getData());
    correctMVNs[1] = new MultivariateNormalDistribution(correctMeans[1], correctCovMats[1].getData());

    MultivariateNormalMixtureExpectationMaximization fitter
        = new MultivariateNormalMixtureExpectationMaximization(data);

    MixtureMultivariateNormalDistribution initialMix
        = MultivariateNormalMixtureExpectationMaximization.estimate(data, 2);
    fitter.fit(initialMix);
    MixtureMultivariateNormalDistribution fittedMix = fitter.getFittedModel();
    List<Pair<Double, MultivariateNormalDistribution>> components = fittedMix.getComponents();

    Assert.assertEquals(correctLogLikelihood,
                        fitter.getLogLikelihood(),
                        Math.ulp(1d));

    int i = 0;
    for (Pair<Double, MultivariateNormalDistribution> component : components) {
        final double weight = component.getFirst();
        final MultivariateNormalDistribution mvn = component.getSecond();
        final double[] mean = mvn.getMeans();
        final RealMatrix covMat = mvn.getCovariances();
        Assert.assertEquals(correctWeights[i], weight, Math.ulp(1d));
        Assert.assertTrue(Arrays.equals(correctMeans[i], mean));
        Assert.assertEquals(correctCovMats[i], covMat);
        i++;
    }
}

Example 4

Source File: MultivariateNormalMixtureExpectationMaximizationTest.java From astor with GNU General Public License v2.0

4 votes

@Test
public void testFit() {
    // Test that the loglikelihood, weights, and models are determined and
    // fitted correctly
    final double[][] data = getTestSamples();
    final double correctLogLikelihood = -4.292431006791994;
    final double[] correctWeights = new double[] { 0.2962324189652912, 0.7037675810347089 };
    
    final double[][] correctMeans = new double[][]{
        {-1.4213112715121132, 1.6924690505757753},
        {4.213612224374709, 7.975621325853645}
    };
    
    final RealMatrix[] correctCovMats = new Array2DRowRealMatrix[2];
    correctCovMats[0] = new Array2DRowRealMatrix(new double[][] {
        { 1.739356907285747, -0.5867644251487614 },
        { -0.5867644251487614, 1.0232932029324642 } }
            );
    correctCovMats[1] = new Array2DRowRealMatrix(new double[][] {
        { 4.245384898007161, 2.5797798966382155 },
        { 2.5797798966382155, 3.9200272522448367 } });
    
    final MultivariateNormalDistribution[] correctMVNs = new MultivariateNormalDistribution[2];
    correctMVNs[0] = new MultivariateNormalDistribution(correctMeans[0], correctCovMats[0].getData());
    correctMVNs[1] = new MultivariateNormalDistribution(correctMeans[1], correctCovMats[1].getData());

    MultivariateNormalMixtureExpectationMaximization fitter
        = new MultivariateNormalMixtureExpectationMaximization(data);

    MixtureMultivariateNormalDistribution initialMix
        = MultivariateNormalMixtureExpectationMaximization.estimate(data, 2);
    fitter.fit(initialMix);
    MixtureMultivariateNormalDistribution fittedMix = fitter.getFittedModel();
    List<Pair<Double, MultivariateNormalDistribution>> components = fittedMix.getComponents();

    Assert.assertEquals(correctLogLikelihood,
                        fitter.getLogLikelihood(),
                        Math.ulp(1d));

    int i = 0;
    for (Pair<Double, MultivariateNormalDistribution> component : components) {
        final double weight = component.getFirst();
        final MultivariateNormalDistribution mvn = component.getSecond();
        final double[] mean = mvn.getMeans();
        final RealMatrix covMat = mvn.getCovariances();
        Assert.assertEquals(correctWeights[i], weight, Math.ulp(1d));
        Assert.assertTrue(Arrays.equals(correctMeans[i], mean));
        Assert.assertEquals(correctCovMats[i], covMat);
        i++;
    }
}

Example 5

Source File: MultivariateNormalMixtureExpectationMaximizationTest.java From astor with GNU General Public License v2.0

4 votes

@Test
public void testFit() {
    // Test that the loglikelihood, weights, and models are determined and
    // fitted correctly
    final double[][] data = getTestSamples();
    final double correctLogLikelihood = -4.292431006791994;
    final double[] correctWeights = new double[] { 0.2962324189652912, 0.7037675810347089 };
    
    final double[][] correctMeans = new double[][]{
        {-1.4213112715121132, 1.6924690505757753},
        {4.213612224374709, 7.975621325853645}
    };
    
    final RealMatrix[] correctCovMats = new Array2DRowRealMatrix[2];
    correctCovMats[0] = new Array2DRowRealMatrix(new double[][] {
        { 1.739356907285747, -0.5867644251487614 },
        { -0.5867644251487614, 1.0232932029324642 } }
            );
    correctCovMats[1] = new Array2DRowRealMatrix(new double[][] {
        { 4.245384898007161, 2.5797798966382155 },
        { 2.5797798966382155, 3.9200272522448367 } });
    
    final MultivariateNormalDistribution[] correctMVNs = new MultivariateNormalDistribution[2];
    correctMVNs[0] = new MultivariateNormalDistribution(correctMeans[0], correctCovMats[0].getData());
    correctMVNs[1] = new MultivariateNormalDistribution(correctMeans[1], correctCovMats[1].getData());

    MultivariateNormalMixtureExpectationMaximization fitter
        = new MultivariateNormalMixtureExpectationMaximization(data);

    MixtureMultivariateNormalDistribution initialMix
        = MultivariateNormalMixtureExpectationMaximization.estimate(data, 2);
    fitter.fit(initialMix);
    MixtureMultivariateNormalDistribution fittedMix = fitter.getFittedModel();
    List<Pair<Double, MultivariateNormalDistribution>> components = fittedMix.getComponents();

    Assert.assertEquals(correctLogLikelihood,
                        fitter.getLogLikelihood(),
                        Math.ulp(1d));

    int i = 0;
    for (Pair<Double, MultivariateNormalDistribution> component : components) {
        final double weight = component.getFirst();
        final MultivariateNormalDistribution mvn = component.getSecond();
        final double[] mean = mvn.getMeans();
        final RealMatrix covMat = mvn.getCovariances();
        Assert.assertEquals(correctWeights[i], weight, Math.ulp(1d));
        Assert.assertTrue(Arrays.equals(correctMeans[i], mean));
        Assert.assertEquals(correctCovMats[i], covMat);
        i++;
    }
}