TSPScore.java

/*
 * Encog(tm) Java Examples v3.4
 * http://www.heatonresearch.com/encog/
 * https://github.com/encog/encog-java-examples
 *
 * 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.
 *   
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 * and trademarks visit:
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 */
package org.encog.examples.ml.tsp.genetic;

import org.encog.examples.ml.tsp.City;
import org.encog.ml.CalculateScore;
import org.encog.ml.MLMethod;
import org.encog.ml.genetic.genome.IntegerArrayGenome;

public class TSPScore implements CalculateScore {

	private City[] cities;
	
	public TSPScore(City[] cities)
	{
		this.cities = cities;
	}
	
	@Override
	public double calculateScore(MLMethod phenotype) {
		double result = 0.0;
		IntegerArrayGenome genome = (IntegerArrayGenome) phenotype;
		int[] path = ((IntegerArrayGenome)genome).getData();
		
		for (int i = 0; i < cities.length - 1; i++) {
			City city1 = cities[path[i]];
			City city2 = cities[path[i+1]];
			
			final double dist = city1.proximity(city2);
			result += dist;
		}
		
		return result;
	}

	public boolean shouldMinimize() {
		return true;
	}

	@Override
	public boolean requireSingleThreaded() {
		return false;
	}

}