edu.snu.cms.reef.ml.kmeans.data.Centroid.java Source code

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Here is the source code for edu.snu.cms.reef.ml.kmeans.data.Centroid.java

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/**
 * Copyright (C) 2014 Seoul National University
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *         http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package edu.snu.cms.reef.ml.kmeans.data;

import org.apache.mahout.math.DenseVector;
import org.apache.mahout.math.Vector;

import java.io.Serializable;
import java.util.Formatter;
import java.util.Locale;

/**
 * A cluster centroid implementation of k-means clustering
 */
public final class Centroid implements Serializable {

    private final int clusterId;
    public Vector vector;

    /**
     * This constructor does not create a deep copy of @param vector.
     */
    public Centroid(final int clusterId, final Vector vector) {
        this.clusterId = clusterId;
        this.vector = vector;
    }

    /**
     * A copy constructor that creates a deep copy of a centroid.
     *
     * The newly created KMeansCentroid does not reference
     * anything from the original KMeansCentroid.
     */
    public Centroid(final Centroid centroid) {
        this.clusterId = centroid.clusterId;
        final Vector vector = new DenseVector(centroid.vector.size());
        for (int i = 0; i < vector.size(); i++) {
            vector.set(i, centroid.vector.get(i));
        }
        this.vector = vector;
    }

    public final int getClusterId() {
        return clusterId;
    }

    @SuppressWarnings("boxing")
    @Override
    public String toString() {
        final StringBuilder b = new StringBuilder("KMeansCentroid(");
        try (final Formatter formatter = new Formatter(b, Locale.US)) {
            formatter.format("Id %d, ", this.clusterId);
            for (int i = 0; i < this.vector.size() - 1; ++i) {
                formatter.format("%1.3f, ", this.vector.get(i));
            }
            formatter.format("%1.3f", this.vector.get(this.vector.size() - 1));
        }
        b.append(')');
        return b.toString();
    }

}