Examples with QuotientOutlierScoreMeta de.lmu.ifi.dbs.elki.result.outlier.QuotientOutlierScoreMeta used on opensource projects

Example 11 with QuotientOutlierScoreMeta

use of de.lmu.ifi.dbs.elki.result.outlier.QuotientOutlierScoreMeta in project elki by elki-project.

the class INFLO method run.

/**
 * Run the algorithm
 *
 * @param database Database to process
 * @param relation Relation to process
 * @return Outlier result
 */
public OutlierResult run(Database database, Relation<O> relation) {
    StepProgress stepprog = LOG.isVerbose() ? new StepProgress("INFLO", 3) : null;
    // Step one: find the kNN
    LOG.beginStep(stepprog, 1, "Materializing nearest-neighbor sets.");
    KNNQuery<O> knnq = DatabaseUtil.precomputedKNNQuery(database, relation, getDistanceFunction(), kplus1);
    // Step two: find the RkNN, minus kNN.
    LOG.beginStep(stepprog, 2, "Materialize reverse NN.");
    ModifiableDBIDs pruned = DBIDUtil.newHashSet();
    // RNNS
    WritableDataStore<ModifiableDBIDs> rnns = DataStoreUtil.makeStorage(relation.getDBIDs(), DataStoreFactory.HINT_TEMP | DataStoreFactory.HINT_HOT, ModifiableDBIDs.class);
    // init the rNN
    for (DBIDIter iditer = relation.iterDBIDs(); iditer.valid(); iditer.advance()) {
        rnns.put(iditer, DBIDUtil.newArray());
    }
    computeNeighborhoods(relation, knnq, pruned, rnns);
    // Step three: compute INFLO scores
    LOG.beginStep(stepprog, 3, "Compute INFLO scores.");
    // Calculate INFLO for any Object
    DoubleMinMax inflominmax = new DoubleMinMax();
    WritableDoubleDataStore inflos = DataStoreUtil.makeDoubleStorage(relation.getDBIDs(), DataStoreFactory.HINT_STATIC);
    // Note: this modifies knns, by adding rknns!
    computeINFLO(relation, pruned, knnq, rnns, inflos, inflominmax);
    LOG.setCompleted(stepprog);
    LOG.statistics(new LongStatistic(INFLO.class.getName() + ".pruned", pruned.size()));
    // Build result representation.
    DoubleRelation scoreResult = new MaterializedDoubleRelation("Influence Outlier Score", "inflo-outlier", inflos, relation.getDBIDs());
    OutlierScoreMeta scoreMeta = new QuotientOutlierScoreMeta(inflominmax.getMin(), inflominmax.getMax(), 0., Double.POSITIVE_INFINITY, 1.);
    return new OutlierResult(scoreMeta, scoreResult);
}

Example 12 with QuotientOutlierScoreMeta

use of de.lmu.ifi.dbs.elki.result.outlier.QuotientOutlierScoreMeta in project elki by elki-project.

the class SimpleKernelDensityLOF method run.

/**
 * Run the naive kernel density LOF algorithm.
 *
 * @param database Database to query
 * @param relation Data to process
 * @return LOF outlier result
 */
public OutlierResult run(Database database, Relation<O> relation) {
    StepProgress stepprog = LOG.isVerbose() ? new StepProgress("KernelDensityLOF", 3) : null;
    final int dim = RelationUtil.dimensionality(relation);
    DBIDs ids = relation.getDBIDs();
    LOG.beginStep(stepprog, 1, "Materializing neighborhoods w.r.t. distance function.");
    KNNQuery<O> knnq = DatabaseUtil.precomputedKNNQuery(database, relation, getDistanceFunction(), k);
    // Compute LRDs
    LOG.beginStep(stepprog, 2, "Computing densities.");
    WritableDoubleDataStore dens = DataStoreUtil.makeDoubleStorage(ids, DataStoreFactory.HINT_HOT | DataStoreFactory.HINT_TEMP);
    FiniteProgress densProgress = LOG.isVerbose() ? new FiniteProgress("Densities", ids.size(), LOG) : null;
    for (DBIDIter it = ids.iter(); it.valid(); it.advance()) {
        final KNNList neighbors = knnq.getKNNForDBID(it, k);
        int count = 0;
        double sum = 0.0;
        // Fast version for double distances
        for (DoubleDBIDListIter neighbor = neighbors.iter(); neighbor.valid(); neighbor.advance()) {
            if (DBIDUtil.equal(neighbor, it)) {
                continue;
            }
            double max = knnq.getKNNForDBID(neighbor, k).getKNNDistance();
            if (max == 0) {
                sum = Double.POSITIVE_INFINITY;
                break;
            }
            final double v = neighbor.doubleValue() / max;
            sum += kernel.density(v) / MathUtil.powi(max, dim);
            count++;
        }
        final double density = count > 0 ? sum / count : 0.;
        dens.putDouble(it, density);
        LOG.incrementProcessed(densProgress);
    }
    LOG.ensureCompleted(densProgress);
    // compute LOF_SCORE of each db object
    LOG.beginStep(stepprog, 3, "Computing KLOFs.");
    WritableDoubleDataStore lofs = DataStoreUtil.makeDoubleStorage(ids, DataStoreFactory.HINT_STATIC);
    // track the maximum value for normalization.
    DoubleMinMax lofminmax = new DoubleMinMax();
    FiniteProgress progressLOFs = LOG.isVerbose() ? new FiniteProgress("KLOF_SCORE for objects", ids.size(), LOG) : null;
    for (DBIDIter it = ids.iter(); it.valid(); it.advance()) {
        final double lrdp = dens.doubleValue(it);
        final double lof;
        if (lrdp > 0) {
            final KNNList neighbors = knnq.getKNNForDBID(it, k);
            double sum = 0.0;
            int count = 0;
            for (DBIDIter neighbor = neighbors.iter(); neighbor.valid(); neighbor.advance()) {
                // skip the point itself
                if (DBIDUtil.equal(neighbor, it)) {
                    continue;
                }
                sum += dens.doubleValue(neighbor);
                count++;
            }
            lof = (lrdp == Double.POSITIVE_INFINITY) ? (sum == Double.POSITIVE_INFINITY ? 1 : 0.) : sum / (count * lrdp);
        } else {
            lof = 1.0;
        }
        lofs.putDouble(it, lof);
        // update minimum and maximum
        lofminmax.put(lof);
        LOG.incrementProcessed(progressLOFs);
    }
    LOG.ensureCompleted(progressLOFs);
    LOG.setCompleted(stepprog);
    // Build result representation.
    DoubleRelation scoreResult = new MaterializedDoubleRelation("Kernel Density Local Outlier Factor", "kernel-density-slof-outlier", lofs, ids);
    OutlierScoreMeta scoreMeta = new QuotientOutlierScoreMeta(lofminmax.getMin(), lofminmax.getMax(), 0.0, Double.POSITIVE_INFINITY, 1.0);
    OutlierResult result = new OutlierResult(scoreMeta, scoreResult);
    return result;
}

Example 13 with QuotientOutlierScoreMeta

use of de.lmu.ifi.dbs.elki.result.outlier.QuotientOutlierScoreMeta in project elki by elki-project.

the class SOF method run.

/**
 * The main run method
 *
 * @param database Database to use (actually unused)
 * @param spatial Relation for neighborhood
 * @param relation Attributes to evaluate
 * @return Outlier result
 */
public OutlierResult run(Database database, Relation<N> spatial, Relation<O> relation) {
    final NeighborSetPredicate npred = getNeighborSetPredicateFactory().instantiate(database, spatial);
    DistanceQuery<O> distFunc = getNonSpatialDistanceFunction().instantiate(relation);
    WritableDoubleDataStore lrds = DataStoreUtil.makeDoubleStorage(relation.getDBIDs(), DataStoreFactory.HINT_TEMP | DataStoreFactory.HINT_HOT);
    WritableDoubleDataStore lofs = DataStoreUtil.makeDoubleStorage(relation.getDBIDs(), DataStoreFactory.HINT_STATIC);
    DoubleMinMax lofminmax = new DoubleMinMax();
    // Compute densities
    for (DBIDIter iditer = relation.iterDBIDs(); iditer.valid(); iditer.advance()) {
        DBIDs neighbors = npred.getNeighborDBIDs(iditer);
        double avg = 0;
        for (DBIDIter iter = neighbors.iter(); iter.valid(); iter.advance()) {
            avg += distFunc.distance(iditer, iter);
        }
        double lrd = 1 / (avg / neighbors.size());
        if (Double.isNaN(lrd)) {
            lrd = 0;
        }
        lrds.putDouble(iditer, lrd);
    }
    // Compute density quotients
    for (DBIDIter iditer = relation.iterDBIDs(); iditer.valid(); iditer.advance()) {
        DBIDs neighbors = npred.getNeighborDBIDs(iditer);
        double avg = 0;
        for (DBIDIter iter = neighbors.iter(); iter.valid(); iter.advance()) {
            avg += lrds.doubleValue(iter);
        }
        final double lrd = (avg / neighbors.size()) / lrds.doubleValue(iditer);
        if (!Double.isNaN(lrd)) {
            lofs.putDouble(iditer, lrd);
            lofminmax.put(lrd);
        } else {
            lofs.putDouble(iditer, 0.0);
        }
    }
    // Build result representation.
    DoubleRelation scoreResult = new MaterializedDoubleRelation("Spatial Outlier Factor", "sof-outlier", lofs, relation.getDBIDs());
    OutlierScoreMeta scoreMeta = new QuotientOutlierScoreMeta(lofminmax.getMin(), lofminmax.getMax(), 0.0, Double.POSITIVE_INFINITY, 1.0);
    OutlierResult or = new OutlierResult(scoreMeta, scoreResult);
    or.addChildResult(npred);
    return or;
}