Example usage for org.apache.commons.math3.ml.clustering Cluster addPoint

Introduction

In this page you can find the example usage for org.apache.commons.math3.ml.clustering Cluster addPoint.

Prototype

public void addPoint(final T point) 

Source Link

Document

Add a point to this cluster.

Usage

From source file:com.yahoo.egads.utilities.DBSCANClusterer.java

/**
 * Expands the cluster to include density-reachable items.
 *
 * @param cluster Cluster to expand/*w w  w. ja  v a2 s  .  c  o  m*/
 * @param point Point to add to cluster
 * @param neighbors List of neighbors
 * @param points the data set
 * @param visited the set of already visited points
 * @return the expanded cluster
 */
private Cluster<T> expandCluster(final Cluster<T> cluster, final T point, final List<T> neighbors,
        final Collection<T> points, final Map<Clusterable, PointStatus> visited) {
    cluster.addPoint(point);
    visited.put(point, PointStatus.PART_OF_CLUSTER);

    List<T> seeds = new ArrayList<T>(neighbors);
    int index = 0;
    while (index < seeds.size()) {
        final T current = seeds.get(index);
        PointStatus pStatus = visited.get(current);
        // only check non-visited points
        if (pStatus == null) {
            final List<T> currentNeighbors = getNeighbors(current, points);
            if (currentNeighbors.size() >= minPts) {
                seeds = merge(seeds, currentNeighbors);
            }
        }

        if (pStatus != PointStatus.PART_OF_CLUSTER) {
            visited.put(current, PointStatus.PART_OF_CLUSTER);
            cluster.addPoint(current);
        }

        index++;
    }
    return cluster;
}

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From source file:com.yahoo.egads.utilities.DBSCANClusterer.java

/**
 * Performs DBSCAN cluster analysis.//from  w  w  w. ja v  a  2s  .  co  m
 *
 * @param points the points to cluster
 * @return the list of clusters
 * @throws NullArgumentException if the data points are null
 */
public List<Cluster<T>> cluster(final Collection<T> points) throws NullArgumentException {

    // sanity checks
    MathUtils.checkNotNull(points);

    final List<Cluster<T>> clusters = new ArrayList<Cluster<T>>();
    final List<Cluster<T>> anomalousClusters = new ArrayList<Cluster<T>>();
    final Cluster<T> anomalyCluster = new Cluster<T>();
    final Map<Clusterable, PointStatus> visited = new HashMap<Clusterable, PointStatus>();

    for (final T point : points) {
        if (visited.get(point) != null) {
            continue;
        }
        final List<T> neighbors = getNeighbors(point, points);
        if (neighbors.size() >= minPts) {
            // DBSCAN does not care about center points
            final Cluster<T> cluster = new Cluster<T>();
            clusters.add(expandCluster(cluster, point, neighbors, points, visited));
        } else {
            visited.put(point, PointStatus.NOISE);
            anomalyCluster.addPoint(point);
        }
    }
    anomalousClusters.add(anomalyCluster);

    return anomalousClusters;
}

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