/*
* 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.neural.som.training.basic.neighborhood;
/**
* A neighborhood function that uses a simple bubble. A radius is defined, and
* any neuron that is plus or minus that width from the winning neuron will be
* updated as a result of training.
*
* @author jheaton
*
*/
public class NeighborhoodBubble implements NeighborhoodFunction {
/**
* The radius of the bubble.
*/
private double radius;
/**
* Create a bubble neighborhood function that will return 1.0 (full update)
* for any neuron that is plus or minus the width distance from the winning
* neuron.
*
* @param radius
* The width of the bubble, this is the distance that the neuron
* can be from the winning neuron. The true width, across the
* bubble, is actually two times this parameter.
*/
public NeighborhoodBubble(final int radius) {
this.radius = radius;
}
/**
* Determine how much the current neuron should be affected by training
* based on its proximity to the winning neuron.
*
* @param currentNeuron
* THe current neuron being evaluated.
* @param bestNeuron
* The winning neuron.
* @return The ratio for this neuron's adjustment.
*/
@Override
public double function(final int currentNeuron,
final int bestNeuron) {
final int distance = Math.abs(bestNeuron - currentNeuron);
if (distance <= this.radius) {
return 1.0;
} else {
return 0.0;
}
}
/**
* @return The radius.
*/
@Override
public double getRadius() {
return this.radius;
}
/**
* Set the radius.
*
* @param radius
* The new radius.
*/
@Override
public void setRadius(final double radius) {
this.radius = radius;
}
}