Example usage for org.apache.mahout.math.decomposer SimpleEigenVerifier SimpleEigenVerifier

Introduction

In this page you can find the example usage for org.apache.mahout.math.decomposer SimpleEigenVerifier SimpleEigenVerifier.

Prototype

SimpleEigenVerifier

Source Link

Usage

From source file:io.ssc.relationdiscovery.SVD.java

License:Open Source License

private void findSingularVectors(Iterable<MatrixSlice> singularVectorCandidates) {

    Map<MatrixSlice, EigenStatus> eigenMetaData = Maps.newHashMap();

    SimpleEigenVerifier verifier = new SimpleEigenVerifier();
    for (MatrixSlice slice : singularVectorCandidates) {
        EigenStatus status = verifier.verify(A, slice.vector());
        eigenMetaData.put(slice, status);
    }//from w  w w .  ja  v  a2  s  .c  o  m

    List<Map.Entry<MatrixSlice, EigenStatus>> prunedEigenMeta = Lists.newArrayList();

    for (Map.Entry<MatrixSlice, EigenStatus> entry : eigenMetaData.entrySet()) {
        if (Math.abs(1 - entry.getValue().getCosAngle()) < MAX_ERROR
                && entry.getValue().getEigenValue() > MIN_EIGENVALUE) {
            prunedEigenMeta.add(entry);
        }
    }

    Collections.sort(prunedEigenMeta, new Comparator<Map.Entry<MatrixSlice, EigenStatus>>() {
        @Override
        public int compare(Map.Entry<MatrixSlice, EigenStatus> e1, Map.Entry<MatrixSlice, EigenStatus> e2) {
            return Ints.compare(e1.getKey().index(), e2.getKey().index());
        }
    });

    int limit = prunedEigenMeta.size() > rank ? rank : prunedEigenMeta.size();
    for (int n = 0; n < limit; n++) {
        Map.Entry<MatrixSlice, EigenStatus> entry = prunedEigenMeta.get(n);
        double eigenvalue = Math.sqrt(entry.getValue().getEigenValue());
        log.info("Eigenvalue {}: {}", n, eigenvalue);
        singularVectors.add(new WeightedVector(entry.getKey().vector(), eigenvalue, n));
    }

}

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