/*
* 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.ml.data.MLDataPair;
import org.encog.util.kmeans.Centroid;
/**
* A centroid for BasicMLDataPair.
*/
public class BasicMLDataPairCentroid
implements Centroid<MLDataPair>, Cloneable
{
/**
* The value the centroid is based on.
*/
private BasicMLData value;
/**
* The number of elements.
*/
private int size;
/**
* Construct the centroid.
* @param o The pair to base the centroid on.
*/
public BasicMLDataPairCentroid(BasicMLDataPair o)
{
this.value = (BasicMLData) o.getInput().clone();
this.size = 1;
}
/**
* {@inheritDoc}
*/
@Override
public void remove(MLDataPair d)
{
double[] a = d.getInputArray();
for (int i = 0; i < value.size(); i++)
value.setData(i,
((value.getData(i) * value.size()) - a[i]) / (value.size()-1));
}
/**
* {@inheritDoc}
*/
@Override
public double distance(MLDataPair d)
{
MLData diff = value.minus(d.getInput());
double sum = 0.;
for (int i = 0; i < diff.size(); i++)
sum += diff.getData(i) * diff.getData(i);
return Math.sqrt(sum);
}
/**
* {@inheritDoc}
*/
@Override
public void add(MLDataPair d) {
double[] a = d.getInputArray();
for (int i = 0; i < value.size(); i++)
value.setData(i,
((value.getData(i) * value.size()) + a[i]) / (value.size()+1));
}
}