Examples with MixtureMultivariateNormalDistribution org.apache.commons.math3.distribution.MixtureMultivariateNormalDistribution used on opensource projects

Example 1 with MixtureMultivariateNormalDistribution

use of org.apache.commons.math3.distribution.MixtureMultivariateNormalDistribution in project gatk-protected by broadinstitute.

the class CoverageDropoutDetector method retrieveGaussianMixtureModelForFilteredTargets.

/** <p>Produces a Gaussian mixture model based on the difference between targets and segment means.</p>
     * <p>Filters targets to populations where more than the minProportion lie in a single segment.</p>
     * <p>Returns null if no pass filtering.  Please note that in these cases,
     * in the rest of this class, we use this to assume that a GMM is not a good model.</p>
     *
     * @param segments  -- segments with segment mean in log2 copy ratio space
     * @param targets -- targets with a log2 copy ratio estimate
     * @param minProportion -- minimum proportion of all targets that a given segment must have in order to be used
     *                      in the evaluation
     * @param numComponents -- number of components to use in the GMM.  Usually, this is 2.
     * @return  never {@code null}.  Fitting result with indications whether it converged or was even attempted.
     */
private MixtureMultivariateNormalFitResult retrieveGaussianMixtureModelForFilteredTargets(final List<ModeledSegment> segments, final TargetCollection<ReadCountRecord.SingleSampleRecord> targets, double minProportion, int numComponents) {
    // For each target in a segment that contains enough targets, normalize the difference against the segment mean
    //  and collapse the filtered targets into the copy ratio estimates.
    final List<Double> filteredTargetsSegDiff = getNumProbeFilteredTargetList(segments, targets, minProportion);
    if (filteredTargetsSegDiff.size() < numComponents) {
        return new MixtureMultivariateNormalFitResult(null, false, false);
    }
    // Assume that Apache Commons wants data points in the first dimension.
    // Note that second dimension of length 2 (instead of 1) is to wrok around funny Apache commons API.
    final double[][] filteredTargetsSegDiff2d = new double[filteredTargetsSegDiff.size()][2];
    // Convert the filtered targets into 2d array (even if second dimension is length 1).  The second dimension is
    //  uncorrelated Gaussian.  This is only to get around funny API in Apache Commons, which will throw an
    //  exception if the length of the second dimension is < 2
    final RandomGenerator rng = RandomGeneratorFactory.createRandomGenerator(new Random(RANDOM_SEED));
    final NormalDistribution nd = new NormalDistribution(rng, 0, .1);
    for (int i = 0; i < filteredTargetsSegDiff.size(); i++) {
        filteredTargetsSegDiff2d[i][0] = filteredTargetsSegDiff.get(i);
        filteredTargetsSegDiff2d[i][1] = nd.sample();
    }
    final MixtureMultivariateNormalDistribution estimateEM0 = MultivariateNormalMixtureExpectationMaximization.estimate(filteredTargetsSegDiff2d, numComponents);
    final MultivariateNormalMixtureExpectationMaximization multivariateNormalMixtureExpectationMaximization = new MultivariateNormalMixtureExpectationMaximization(filteredTargetsSegDiff2d);
    try {
        multivariateNormalMixtureExpectationMaximization.fit(estimateEM0);
    } catch (final MaxCountExceededException | ConvergenceException | SingularMatrixException e) {
        //  did not converge.  Include the model as it was when the exception was thrown.
        return new MixtureMultivariateNormalFitResult(multivariateNormalMixtureExpectationMaximization.getFittedModel(), false, true);
    }
    return new MixtureMultivariateNormalFitResult(multivariateNormalMixtureExpectationMaximization.getFittedModel(), true, true);
}

Example 2 with MixtureMultivariateNormalDistribution

use of org.apache.commons.math3.distribution.MixtureMultivariateNormalDistribution in project gatk by broadinstitute.

the class CoverageDropoutDetector method retrieveGaussianMixtureModelForFilteredTargets.

/** <p>Produces a Gaussian mixture model based on the difference between targets and segment means.</p>
     * <p>Filters targets to populations where more than the minProportion lie in a single segment.</p>
     * <p>Returns null if no pass filtering.  Please note that in these cases,
     * in the rest of this class, we use this to assume that a GMM is not a good model.</p>
     *
     * @param segments  -- segments with segment mean in log2 copy ratio space
     * @param targets -- targets with a log2 copy ratio estimate
     * @param minProportion -- minimum proportion of all targets that a given segment must have in order to be used
     *                      in the evaluation
     * @param numComponents -- number of components to use in the GMM.  Usually, this is 2.
     * @return  never {@code null}.  Fitting result with indications whether it converged or was even attempted.
     */
private MixtureMultivariateNormalFitResult retrieveGaussianMixtureModelForFilteredTargets(final List<ModeledSegment> segments, final TargetCollection<ReadCountRecord.SingleSampleRecord> targets, double minProportion, int numComponents) {
    // For each target in a segment that contains enough targets, normalize the difference against the segment mean
    //  and collapse the filtered targets into the copy ratio estimates.
    final List<Double> filteredTargetsSegDiff = getNumProbeFilteredTargetList(segments, targets, minProportion);
    if (filteredTargetsSegDiff.size() < numComponents) {
        return new MixtureMultivariateNormalFitResult(null, false, false);
    }
    // Assume that Apache Commons wants data points in the first dimension.
    // Note that second dimension of length 2 (instead of 1) is to wrok around funny Apache commons API.
    final double[][] filteredTargetsSegDiff2d = new double[filteredTargetsSegDiff.size()][2];
    // Convert the filtered targets into 2d array (even if second dimension is length 1).  The second dimension is
    //  uncorrelated Gaussian.  This is only to get around funny API in Apache Commons, which will throw an
    //  exception if the length of the second dimension is < 2
    final RandomGenerator rng = RandomGeneratorFactory.createRandomGenerator(new Random(RANDOM_SEED));
    final NormalDistribution nd = new NormalDistribution(rng, 0, .1);
    for (int i = 0; i < filteredTargetsSegDiff.size(); i++) {
        filteredTargetsSegDiff2d[i][0] = filteredTargetsSegDiff.get(i);
        filteredTargetsSegDiff2d[i][1] = nd.sample();
    }
    final MixtureMultivariateNormalDistribution estimateEM0 = MultivariateNormalMixtureExpectationMaximization.estimate(filteredTargetsSegDiff2d, numComponents);
    final MultivariateNormalMixtureExpectationMaximization multivariateNormalMixtureExpectationMaximization = new MultivariateNormalMixtureExpectationMaximization(filteredTargetsSegDiff2d);
    try {
        multivariateNormalMixtureExpectationMaximization.fit(estimateEM0);
    } catch (final MaxCountExceededException | ConvergenceException | SingularMatrixException e) {
        //  did not converge.  Include the model as it was when the exception was thrown.
        return new MixtureMultivariateNormalFitResult(multivariateNormalMixtureExpectationMaximization.getFittedModel(), false, true);
    }
    return new MixtureMultivariateNormalFitResult(multivariateNormalMixtureExpectationMaximization.getFittedModel(), true, true);
}