/* * Encog(tm) Core v3.4 - Java Version * http://www.heatonresearch.com/encog/ * https://github.com/encog/encog-java-core * Copyright 2008-2016 Heaton Research, Inc. * * 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. * * For more information on Heaton Research copyrights, licenses * and trademarks visit: * http://www.heatonresearch.com/copyright */ package org.encog.ml.data.basic; import org.encog.ml.data.MLData; import org.encog.util.kmeans.Centroid; /** * A basic implementation of a centroid. */ public class BasicMLDataCentroid implements Centroid<MLData>, Cloneable { /** * The value this centroid is based on. */ private BasicMLData value; /** * The number of elements. */ private int size; /** * Construct the centroid. * @param o The object to base the centroid on. */ public BasicMLDataCentroid(MLData o) { this.value = (BasicMLData) o.clone(); this.size = 1; } /** * {@inheritDoc} */ public void add(MLData d) { double[] a = d.getData(); for (int i = 0; i < value.size(); i++) value.setData(i, ((value.getData(i) * this.size) + a[i]) / (this.size+1)); this.size++; } /** * {@inheritDoc} */ public void remove(MLData d) { double[] a = d.getData(); for (int i = 0; i < value.size(); i++) value.setData(i, ((value.getData(i) * this.size) - a[i]) / (this.size-1)); this.size--; } /** * {@inheritDoc} */ public double distance(MLData d) { MLData diff = value.minus(d); double sum = 0.; for (int i = 0; i < diff.size(); i++) sum += diff.getData(i) * diff.getData(i); return Math.sqrt(sum); } }