Examples with NNDescent de.lmu.ifi.dbs.elki.index.preprocessed.knn.NNDescent used on opensource projects

Example 1 with NNDescent

use of de.lmu.ifi.dbs.elki.index.preprocessed.knn.NNDescent in project elki by elki-project.

the class NNDescentTest method testPreprocessor.

@Test
public void testPreprocessor() {
    Database db = AbstractSimpleAlgorithmTest.makeSimpleDatabase(dataset, shoulds);
    Relation<DoubleVector> rel = db.getRelation(TypeUtil.DOUBLE_VECTOR_FIELD);
    DistanceQuery<DoubleVector> distanceQuery = db.getDistanceQuery(rel, EuclideanDistanceFunction.STATIC);
    // get linear queries
    LinearScanDistanceKNNQuery<DoubleVector> lin_knn_query = new LinearScanDistanceKNNQuery<>(distanceQuery);
    // get preprocessed queries
    ListParameterization config = new ListParameterization();
    config.addParameter(NNDescent.Factory.DISTANCE_FUNCTION_ID, distanceQuery.getDistanceFunction());
    config.addParameter(NNDescent.Factory.K_ID, k);
    config.addParameter(NNDescent.Factory.Parameterizer.SEED_ID, 0);
    config.addParameter(NNDescent.Factory.Parameterizer.DELTA_ID, 0.1);
    config.addParameter(NNDescent.Factory.Parameterizer.RHO_ID, 0.5);
    NNDescent.Factory<DoubleVector> preprocf = ClassGenericsUtil.parameterizeOrAbort(NNDescent.Factory.class, config);
    NNDescent<DoubleVector> preproc = preprocf.instantiate(rel);
    KNNQuery<DoubleVector> preproc_knn_query = preproc.getKNNQuery(distanceQuery, k);
    // add as index
    db.getHierarchy().add(rel, preproc);
    assertFalse("Preprocessor knn query class incorrect.", preproc_knn_query instanceof LinearScanDistanceKNNQuery);
    // test queries
    testKNNQueries(rel, lin_knn_query, preproc_knn_query, k);
    // also test partial queries, forward only
    testKNNQueries(rel, lin_knn_query, preproc_knn_query, k / 2);
}