/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.
*/
package org.apache.mahout.ga.watchmaker.utils;
import com.google.common.collect.Maps;
import org.uncommons.watchmaker.framework.FitnessEvaluator;
import org.apache.mahout.common.RandomUtils;
import java.util.List;
import java.util.Map;
import java.util.Random;
/**
* Dummy FitnessEvaluator that stores the evaluations it calculates. Uses a static storage to handle the evaluator
* duplication when passed as a Job parameter.
*/
public final class DummyEvaluator implements FitnessEvaluator<DummyCandidate> {
private final Random rng = RandomUtils.getRandom();
private static final Map<Integer, Double> evaluations = Maps.newHashMap();
public static double getFitness(Integer key) {
if (!evaluations.containsKey(key)) {
throw new IllegalArgumentException("Fitness not found");
}
return evaluations.get(key);
}
public static void clearEvaluations() {
evaluations.clear();
}
@Override
public double getFitness(DummyCandidate candidate,
List<? extends DummyCandidate> population) {
if (evaluations.containsKey(candidate.getIndex())) {
throw new IllegalArgumentException("Duplicate Fitness");
}
double fitness = rng.nextDouble();
evaluations.put(candidate.getIndex(), fitness);
return fitness;
}
@Override
public boolean isNatural() {
return false;
}
}