/*
* RapidMiner
*
* Copyright (C) 2001-2008 by Rapid-I and the contributors
*
* Complete list of developers available at our web site:
*
* http://rapid-i.com
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see http://www.gnu.org/licenses/.
*/
package com.rapidminer.operator.features.weighting;
import java.util.LinkedList;
import java.util.List;
import com.rapidminer.example.Attribute;
import com.rapidminer.example.ExampleSet;
import com.rapidminer.example.set.AttributeWeightedExampleSet;
import com.rapidminer.operator.OperatorDescription;
import com.rapidminer.operator.features.Individual;
import com.rapidminer.operator.features.Population;
import com.rapidminer.operator.features.PopulationOperator;
import com.rapidminer.operator.features.selection.AbstractGeneticAlgorithm;
import com.rapidminer.operator.features.selection.SelectionCrossover;
import com.rapidminer.parameter.ParameterType;
import com.rapidminer.parameter.ParameterTypeBoolean;
import com.rapidminer.parameter.ParameterTypeCategory;
import com.rapidminer.parameter.ParameterTypeDouble;
import com.rapidminer.parameter.UndefinedParameterError;
/**
* This operator performs the weighting of features with an evolutionary
* strategies approach. The variance of the gaussian additive mutation can be
* adapted by a 1/5-rule.
*
* @author Ingo Mierswa
* @version $Id: EvolutionaryWeighting.java,v 1.27 2006/04/14 07:47:17
* ingomierswa Exp $
*/
public class EvolutionaryWeighting extends AbstractGeneticAlgorithm {
/** The parameter name for "The (initial) variance for each mutation." */
public static final String PARAMETER_MUTATION_VARIANCE = "mutation_variance";
/** The parameter name for "If set to true, the 1/5 rule for variance adaption is used." */
public static final String PARAMETER_1_5_RULE = "1_5_rule";
/** The parameter name for "If set to true, the weights are bounded between 0 and 1." */
public static final String PARAMETER_BOUNDED_MUTATION = "bounded_mutation";
/** The parameter name for "Probability for an individual to be selected for crossover." */
public static final String PARAMETER_P_CROSSOVER = "p_crossover";
/** The parameter name for "Type of the crossover." */
public static final String PARAMETER_CROSSOVER_TYPE = "crossover_type";
private WeightingMutation weighting = null;
public EvolutionaryWeighting(OperatorDescription description) {
super(description);
}
public PopulationOperator getCrossoverPopulationOperator(ExampleSet eSet) throws UndefinedParameterError {
return new WeightingCrossover(getParameterAsInt(PARAMETER_CROSSOVER_TYPE), getParameterAsDouble(PARAMETER_P_CROSSOVER), getRandom());
}
public PopulationOperator getMutationPopulationOperator(ExampleSet eSet) throws UndefinedParameterError {
this.weighting = new WeightingMutation(getParameterAsDouble(PARAMETER_MUTATION_VARIANCE), getParameterAsBoolean(PARAMETER_BOUNDED_MUTATION), getRandom());
return weighting;
}
protected List<PopulationOperator> getPostProcessingPopulationOperators(ExampleSet eSet) throws UndefinedParameterError {
List<PopulationOperator> otherPostOps = new LinkedList<PopulationOperator>();
if (getParameterAsBoolean(PARAMETER_1_5_RULE)) {
otherPostOps.add(new VarianceAdaption(weighting, eSet.getAttributes().size()));
}
return otherPostOps;
}
public Population createInitialPopulation(ExampleSet exampleSet) throws UndefinedParameterError {
int numberOfIndividuals = getParameterAsInt(PARAMETER_POPULATION_SIZE);
Population initPop = new Population();
for (int i = 0; i < numberOfIndividuals; i++) {
AttributeWeightedExampleSet nes = new AttributeWeightedExampleSet((ExampleSet) exampleSet.clone());
for (Attribute attribute : nes.getAttributes()) {
nes.setWeight(attribute, getRandom().nextDouble());
}
initPop.add(new Individual(nes));
}
return initPop;
}
public List<ParameterType> getParameterTypes() {
List<ParameterType> types = super.getParameterTypes();
types.add(new ParameterTypeDouble(PARAMETER_MUTATION_VARIANCE, "The (initial) variance for each mutation.", 0.0d, Double.POSITIVE_INFINITY, 1.0d));
types.add(new ParameterTypeBoolean(PARAMETER_1_5_RULE, "If set to true, the 1/5 rule for variance adaption is used.", true));
types.add(new ParameterTypeBoolean(PARAMETER_BOUNDED_MUTATION, "If set to true, the weights are bounded between 0 and 1.", false));
ParameterType type = new ParameterTypeDouble(PARAMETER_P_CROSSOVER, "Probability for an individual to be selected for crossover.", 0.0d, 1.0d, 0.0d);
type.setExpert(false);
types.add(type);
types.add(new ParameterTypeCategory(PARAMETER_CROSSOVER_TYPE, "Type of the crossover.", SelectionCrossover.CROSSOVER_TYPES, SelectionCrossover.UNIFORM));
return types;
}
}