NEATUtil.java

/*
 * 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.neat;

import org.encog.ml.CalculateScore;
import org.encog.ml.ea.opp.CompoundOperator;
import org.encog.ml.ea.opp.selection.TruncationSelection;
import org.encog.ml.ea.train.basic.TrainEA;
import org.encog.neural.hyperneat.HyperNEATCODEC;
import org.encog.neural.neat.training.opp.NEATCrossover;
import org.encog.neural.neat.training.opp.NEATMutateAddLink;
import org.encog.neural.neat.training.opp.NEATMutateAddNode;
import org.encog.neural.neat.training.opp.NEATMutateRemoveLink;
import org.encog.neural.neat.training.opp.NEATMutateWeights;
import org.encog.neural.neat.training.opp.links.MutatePerturbLinkWeight;
import org.encog.neural.neat.training.opp.links.MutateResetLinkWeight;
import org.encog.neural.neat.training.opp.links.SelectFixed;
import org.encog.neural.neat.training.opp.links.SelectProportion;
import org.encog.neural.neat.training.species.OriginalNEATSpeciation;

/**
 * NEAT does not make use of a special trainer. Typically the generic TrainEA
 * trainer is used. This utility class creates a NEAT compatible TrainEA class.
 * 
 * -----------------------------------------------------------------------------
 * http://www.cs.ucf.edu/~kstanley/ Encog's NEAT implementation was drawn from
 * the following three Journal Articles. For more complete BibTeX sources, see
 * NEATNetwork.java.
 * 
 * Evolving Neural Networks Through Augmenting Topologies
 * 
 * Generating Large-Scale Neural Networks Through Discovering Geometric
 * Regularities
 * 
 * Automatic feature selection in neuroevolution
 */
public class NEATUtil {
	public static TrainEA constructNEATTrainer(
			final CalculateScore calculateScore, final int inputCount,
			final int outputCount, final int populationSize) {
		final NEATPopulation pop = new NEATPopulation(inputCount, outputCount,
				populationSize);
		pop.reset();
		return constructNEATTrainer(pop, calculateScore);
	}

	/**
	 * Construct a NEAT (or HyperNEAT trainer.
	 * @param population The population.
	 * @param calculateScore The score function.
	 * @return The NEAT EA trainer.
	 */
	public static TrainEA constructNEATTrainer(final NEATPopulation population,
			final CalculateScore calculateScore) {
		final TrainEA result = new TrainEA(population, calculateScore);
		result.setSpeciation(new OriginalNEATSpeciation());

		result.setSelection(new TruncationSelection(result, 0.3));
		final CompoundOperator weightMutation = new CompoundOperator();
		weightMutation.getComponents().add(
				0.1125,
				new NEATMutateWeights(new SelectFixed(1),
						new MutatePerturbLinkWeight(0.02)));
		weightMutation.getComponents().add(
				0.1125,
				new NEATMutateWeights(new SelectFixed(2),
						new MutatePerturbLinkWeight(0.02)));
		weightMutation.getComponents().add(
				0.1125,
				new NEATMutateWeights(new SelectFixed(3),
						new MutatePerturbLinkWeight(0.02)));
		weightMutation.getComponents().add(
				0.1125,
				new NEATMutateWeights(new SelectProportion(0.02),
						new MutatePerturbLinkWeight(0.02)));
		weightMutation.getComponents().add(
				0.1125,
				new NEATMutateWeights(new SelectFixed(1),
						new MutatePerturbLinkWeight(1)));
		weightMutation.getComponents().add(
				0.1125,
				new NEATMutateWeights(new SelectFixed(2),
						new MutatePerturbLinkWeight(1)));
		weightMutation.getComponents().add(
				0.1125,
				new NEATMutateWeights(new SelectFixed(3),
						new MutatePerturbLinkWeight(1)));
		weightMutation.getComponents().add(
				0.1125,
				new NEATMutateWeights(new SelectProportion(0.02),
						new MutatePerturbLinkWeight(1)));
		weightMutation.getComponents().add(
				0.03,
				new NEATMutateWeights(new SelectFixed(1),
						new MutateResetLinkWeight()));
		weightMutation.getComponents().add(
				0.03,
				new NEATMutateWeights(new SelectFixed(2),
						new MutateResetLinkWeight()));
		weightMutation.getComponents().add(
				0.03,
				new NEATMutateWeights(new SelectFixed(3),
						new MutateResetLinkWeight()));
		weightMutation.getComponents().add(
				0.01,
				new NEATMutateWeights(new SelectProportion(0.02),
						new MutateResetLinkWeight()));
		weightMutation.getComponents().finalizeStructure();

		result.setChampMutation(weightMutation);
		result.addOperation(0.5, new NEATCrossover());
		result.addOperation(0.494, weightMutation);
		result.addOperation(0.0005, new NEATMutateAddNode());
		result.addOperation(0.005, new NEATMutateAddLink());
		result.addOperation(0.0005, new NEATMutateRemoveLink());
		result.getOperators().finalizeStructure();

		if (population.isHyperNEAT()) {
			result.setCODEC(new HyperNEATCODEC());
		} else {
			result.setCODEC(new NEATCODEC());
		}

		return result;
	}
}