Examples with KNNList de.lmu.ifi.dbs.elki.database.ids.KNNList used on opensource projects

Example 1 with KNNList

use of de.lmu.ifi.dbs.elki.database.ids.KNNList in project elki by elki-project.

the class GeoIndexing method main.

public static void main(String[] args) {
    // Set the logging level to statistics:
    LoggingConfiguration.setStatistics();
    // Generate a random data set.
    Random rand = new Random(0L);
    // Note: ELKI has a nice data generator class, use that instead.
    double[][] data = new double[100000][];
    for (int i = 0; i < data.length; i++) {
        data[i] = randomLatitudeLongitude(rand);
    }
    // Adapter to load data from an existing array.
    DatabaseConnection dbc = new ArrayAdapterDatabaseConnection(data);
    // Since the R-tree has so many options, it is a bit easier to configure it
    // using the parameterization API, which handles defaults, instantiation,
    // and additional constraint checks.
    RStarTreeFactory<?> indexfactory = // 
    new ELKIBuilder<>(RStarTreeFactory.class).with(AbstractPageFileFactory.Parameterizer.PAGE_SIZE_ID, // 
    512).with(RStarTreeFactory.Parameterizer.BULK_SPLIT_ID, // 
    SortTileRecursiveBulkSplit.class).build();
    // Create the database, and initialize it.
    Database db = new StaticArrayDatabase(dbc, Arrays.asList(indexfactory));
    // This will build the index of the database.
    db.initialize();
    // Relation containing the number vectors we put in above:
    Relation<NumberVector> rel = db.getRelation(TypeUtil.NUMBER_VECTOR_FIELD);
    // We can use this to identify rows of the input data below.
    DBIDRange ids = (DBIDRange) rel.getDBIDs();
    // For all indexes, dump their statistics.
    for (It<Index> it = db.getHierarchy().iterDescendants(db).filter(Index.class); it.valid(); it.advance()) {
        it.get().logStatistics();
    }
    // We use the WGS84 earth model, and "latitude, longitude" coordinates:
    // This distance function returns meters.
    LatLngDistanceFunction df = new LatLngDistanceFunction(WGS84SpheroidEarthModel.STATIC);
    // k nearest neighbor query:
    KNNQuery<NumberVector> knnq = QueryUtil.getKNNQuery(rel, df);
    // Let's find the closest points to New York:
    DoubleVector newYork = DoubleVector.wrap(new double[] { 40.730610, -73.935242 });
    KNNList knns = knnq.getKNNForObject(newYork, 10);
    // Iterate over all results.
    System.out.println("Close to New York:");
    for (DoubleDBIDListIter it = knns.iter(); it.valid(); it.advance()) {
        // To kilometers
        double km = it.doubleValue() / 1000;
        System.out.println(rel.get(it) + " distance: " + km + " km row: " + ids.getOffset(it));
    }
    // Many other indexes will fail if we search close to the date line.
    DoubleVector tuvalu = DoubleVector.wrap(new double[] { -7.4784205, 178.679924 });
    knns = knnq.getKNNForObject(tuvalu, 10);
    // Iterate over all results.
    System.out.println("Close to Tuvalu:");
    for (DoubleDBIDListIter it = knns.iter(); it.valid(); it.advance()) {
        // To kilometers
        double km = it.doubleValue() / 1000;
        System.out.println(rel.get(it) + " distance: " + km + " km row: " + ids.getOffset(it));
    }
    // the distances to a few points in the data set.
    for (It<Index> it = db.getHierarchy().iterDescendants(db).filter(Index.class); it.valid(); it.advance()) {
        it.get().logStatistics();
    }
}

Example 2 with KNNList

use of de.lmu.ifi.dbs.elki.database.ids.KNNList in project elki by elki-project.

the class ODIN method run.

/**
 * Run the ODIN algorithm
 *
 * Tutorial note: the <em>signature</em> of this method depends on the types
 * that we requested in the {@link #getInputTypeRestriction} method. Here we
 * requested a single relation of type {@code O} , the data type of our
 * distance function.
 *
 * @param database Database to run on.
 * @param relation Relation to process.
 * @return ODIN outlier result.
 */
public OutlierResult run(Database database, Relation<O> relation) {
    // Get the query functions:
    DistanceQuery<O> dq = database.getDistanceQuery(relation, getDistanceFunction());
    KNNQuery<O> knnq = database.getKNNQuery(dq, k);
    // Get the objects to process, and a data storage for counting and output:
    DBIDs ids = relation.getDBIDs();
    WritableDoubleDataStore scores = DataStoreUtil.makeDoubleStorage(ids, DataStoreFactory.HINT_DB, 0.);
    // Process all objects
    for (DBIDIter iter = ids.iter(); iter.valid(); iter.advance()) {
        // Find the nearest neighbors (using an index, if available!)
        KNNList neighbors = knnq.getKNNForDBID(iter, k);
        // For each neighbor, except ourselves, increase the in-degree:
        for (DBIDIter nei = neighbors.iter(); nei.valid(); nei.advance()) {
            if (DBIDUtil.equal(iter, nei)) {
                continue;
            }
            scores.put(nei, scores.doubleValue(nei) + 1);
        }
    }
    // Compute maximum
    double min = Double.POSITIVE_INFINITY, max = 0.0;
    for (DBIDIter iter = ids.iter(); iter.valid(); iter.advance()) {
        min = Math.min(min, scores.doubleValue(iter));
        max = Math.max(max, scores.doubleValue(iter));
    }
    // Wrap the result and add metadata.
    // By actually specifying theoretical min, max and baseline, we get a better
    // visualization (try it out - or see the screenshots in the tutorial)!
    OutlierScoreMeta meta = new InvertedOutlierScoreMeta(min, max, 0., ids.size() - 1, k);
    DoubleRelation rel = new MaterializedDoubleRelation("ODIN In-Degree", "odin", scores, ids);
    return new OutlierResult(meta, rel);
}

Example 3 with KNNList

use of de.lmu.ifi.dbs.elki.database.ids.KNNList in project elki by elki-project.

the class MaterializeKNNAndRKNNPreprocessor method objectsRemoved.

@Override
protected void objectsRemoved(DBIDs ids) {
    StepProgress stepprog = getLogger().isVerbose() ? new StepProgress(3) : null;
    // For debugging: valid DBIDs still in the database.
    final DBIDs valid = DBIDUtil.ensureSet(distanceQuery.getRelation().getDBIDs());
    ArrayDBIDs aids = DBIDUtil.ensureArray(ids);
    // delete the materialized (old) kNNs and RkNNs
    getLogger().beginStep(stepprog, 1, "New deletions ocurred, remove their materialized kNNs and RkNNs.");
    // Temporary storage of removed lists
    List<KNNList> kNNs = new ArrayList<>(ids.size());
    List<TreeSet<DoubleDBIDPair>> rkNNs = new ArrayList<>(ids.size());
    for (DBIDIter iter = aids.iter(); iter.valid(); iter.advance()) {
        kNNs.add(storage.get(iter));
        for (DBIDIter it = storage.get(iter).iter(); it.valid(); it.advance()) {
            if (!valid.contains(it) && !ids.contains(it)) {
                LOG.warning("False kNN: " + it);
            }
        }
        storage.delete(iter);
        rkNNs.add(materialized_RkNN.get(iter));
        for (DoubleDBIDPair it : materialized_RkNN.get(iter)) {
            if (!valid.contains(it) && !ids.contains(it)) {
                LOG.warning("False RkNN: " + it);
            }
        }
        materialized_RkNN.delete(iter);
    }
    // Keep only those IDs not also removed
    ArrayDBIDs kNN_ids = affectedkNN(kNNs, aids);
    ArrayDBIDs rkNN_ids = affectedRkNN(rkNNs, aids);
    // update the affected kNNs and RkNNs
    getLogger().beginStep(stepprog, 2, "New deletions ocurred, update the affected kNNs and RkNNs.");
    // Recompute the kNN for affected objects (in rkNN lists)
    {
        List<? extends KNNList> kNNList = knnQuery.getKNNForBulkDBIDs(rkNN_ids, k);
        int i = 0;
        for (DBIDIter reknn = rkNN_ids.iter(); reknn.valid(); reknn.advance(), i++) {
            if (kNNList.get(i) == null && !valid.contains(reknn)) {
                LOG.warning("BUG in online kNN/RkNN maintainance: " + DBIDUtil.toString(reknn) + " no longer in database.");
                continue;
            }
            assert (kNNList.get(i) != null);
            storage.put(reknn, kNNList.get(i));
            for (DoubleDBIDListIter it = kNNList.get(i).iter(); it.valid(); it.advance()) {
                materialized_RkNN.get(it).add(makePair(it, reknn));
            }
        }
    }
    // remove objects from RkNNs of objects (in kNN lists)
    {
        SetDBIDs idsSet = DBIDUtil.ensureSet(ids);
        for (DBIDIter nn = kNN_ids.iter(); nn.valid(); nn.advance()) {
            TreeSet<DoubleDBIDPair> rkNN = materialized_RkNN.get(nn);
            for (Iterator<DoubleDBIDPair> it = rkNN.iterator(); it.hasNext(); ) {
                if (idsSet.contains(it.next())) {
                    it.remove();
                }
            }
        }
    }
    // inform listener
    getLogger().beginStep(stepprog, 3, "New deletions ocurred, inform listeners.");
    fireKNNsRemoved(ids, rkNN_ids);
    getLogger().ensureCompleted(stepprog);
}

Example 4 with KNNList

use of de.lmu.ifi.dbs.elki.database.ids.KNNList in project elki by elki-project.

the class MaterializeKNNAndRKNNPreprocessor method affectedkNN.

/**
 * Extracts and removes the DBIDs in the given collections.
 *
 * @param extract a list of lists of DistanceResultPair to extract
 * @param remove the ids to remove
 * @return the DBIDs in the given collection
 */
protected ArrayDBIDs affectedkNN(List<? extends KNNList> extract, DBIDs remove) {
    HashSetModifiableDBIDs ids = DBIDUtil.newHashSet();
    for (KNNList drps : extract) {
        for (DBIDIter iter = drps.iter(); iter.valid(); iter.advance()) {
            ids.add(iter);
        }
    }
    ids.removeDBIDs(remove);
    // Convert back to array
    return DBIDUtil.newArray(ids);
}

Example 5 with KNNList

use of de.lmu.ifi.dbs.elki.database.ids.KNNList in project elki by elki-project.

the class MaterializeKNNPreprocessor method updateKNNsAfterDeletion.

/**
 * Updates the kNNs of the RkNNs of the specified ids.
 *
 * @param ids the ids of deleted objects causing a change of materialized kNNs
 * @return the RkNNs of the specified ids, i.e. the kNNs which have been
 *         updated
 */
private ArrayDBIDs updateKNNsAfterDeletion(DBIDs ids) {
    SetDBIDs idsSet = DBIDUtil.ensureSet(ids);
    ArrayModifiableDBIDs rkNN_ids = DBIDUtil.newArray();
    for (DBIDIter iditer = relation.iterDBIDs(); iditer.valid(); iditer.advance()) {
        KNNList kNNs = storage.get(iditer);
        for (DBIDIter it = kNNs.iter(); it.valid(); it.advance()) {
            if (idsSet.contains(it)) {
                rkNN_ids.add(iditer);
                break;
            }
        }
    }
    // update the kNNs of the RkNNs
    List<? extends KNNList> kNNList = knnQuery.getKNNForBulkDBIDs(rkNN_ids, k);
    DBIDIter iter = rkNN_ids.iter();
    for (int i = 0; i < rkNN_ids.size(); i++, iter.advance()) {
        storage.put(iter, kNNList.get(i));
    }
    return rkNN_ids;
}