| 1 | package de.uka.ipd.sdq.tcfmoop.terminationcriteria; |
| 2 | |
| 3 | import java.util.HashMap; |
| 4 | import java.util.LinkedList; |
| 5 | import java.util.List; |
| 6 | import java.util.Map; |
| 7 | |
| 8 | import org.opt4j.core.Archive; |
| 9 | import org.opt4j.core.Individual; |
| 10 | import org.opt4j.core.Population; |
| 11 | |
| 12 | import de.uka.ipd.sdq.tcfmoop.config.IConfiguration; |
| 13 | import de.uka.ipd.sdq.tcfmoop.config.ParetoOptimalSetStabilityConfig; |
| 14 | import de.uka.ipd.sdq.tcfmoop.config.ParetoOptimalSetStabilityConfig.EvaluationMode; |
| 15 | import de.uka.ipd.sdq.tcfmoop.outputtree.Node; |
| 16 | import de.uka.ipd.sdq.tcfmoop.outputtree.Node.NodeType; |
| 17 | |
| 18 | /** |
| 19 | * @author Atanas Dimitrov |
| 20 | */ |
| 21 | public class ParetoOptimalSetStabilityCriterion extends |
| 22 | AbstractTerminationCriterion { |
| 23 | |
| 24 | /* |
| 25 | * The evaluation modes that this criterion supports. If mode is set to EXACT_NUMBER, then the criterion searches every time |
| 26 | * for exactly x candidates who have survived for n iterations. If PERCENTAGE is set as evaluation mode, then the number of |
| 27 | * the survived candidates is relative to the current amount of candidates in the archive. |
| 28 | */ |
| 29 | private EvaluationMode mode; |
| 30 | //The minimum number of individual who must survive |
| 31 | private int minimumSurvivors; |
| 32 | //The minimum number of individual in percentage who must survive |
| 33 | private Double minimumSurvivorsInPercentage; |
| 34 | //The minimum amount of iterations these individuals have to survive |
| 35 | private int minimumIterationsToSurvive; |
| 36 | //Stores information about the individuals, including survived generations |
| 37 | private Map<Individual, IndividualStatistics> survivalsCounter; |
| 38 | //Denotes how many individuals have remained pareto optimal the longest or how many have reached the required minimum number of iterations to survive. |
| 39 | private int numberOfIndividualsThatHasRemainedOptimalTheLongest; |
| 40 | //Shows the currently reached maximum number of survived iterations. |
| 41 | private int currentlyReachedMaxNumberOfIterations; |
| 42 | |
| 43 | //OutputNodes |
| 44 | //static |
| 45 | @SuppressWarnings("unused") |
| 46 | private Node evaluationModeNode; |
| 47 | //dynamic |
| 48 | private Node survivedGenerationsNode; |
| 49 | private Node survivorsNode; |
| 50 | |
| 51 | public ParetoOptimalSetStabilityCriterion(IConfiguration conf, Population population, |
| 52 | Archive archive) { |
| 53 | super(conf, population, archive); |
| 54 | if((conf instanceof ParetoOptimalSetStabilityConfig) && conf.validateConfiguration()){ |
| 55 | this.minimumIterationsToSurvive = ((ParetoOptimalSetStabilityConfig)(conf)).getMinimumIterationsToSurvive(); |
| 56 | this.mode = ((ParetoOptimalSetStabilityConfig)(conf)).getEvaluationMode(); |
| 57 | if(this.mode == EvaluationMode.EXACT_NUMBER){ |
| 58 | this.minimumSurvivors = ((ParetoOptimalSetStabilityConfig)(conf)).getMinimumSurvivors(); |
| 59 | }else{ |
| 60 | this.minimumSurvivorsInPercentage = ((ParetoOptimalSetStabilityConfig)(conf)).getMinimumSurvivorsInPercentage(); |
| 61 | } |
| 62 | }else{ |
| 63 | throw new RuntimeException("ParetoOptimalSetStabilityCriterion.initialize: " + |
| 64 | "wrong or invalid configuration object"); |
| 65 | } |
| 66 | survivalsCounter = new HashMap<Individual, IndividualStatistics>(); |
| 67 | this.initializeOutputTree(archive); |
| 68 | } |
| 69 | |
| 70 | private void initializeOutputTree(Archive archive){ |
| 71 | this.outputInformation.updateValue("Pareto Optimal Set Stability"); |
| 72 | this.outputInformation.getChildren().clear(); |
| 73 | |
| 74 | this.evaluationModeNode = this.outputInformation.addChild("Evaluation Mode: " + this.mode.name(), NodeType.PARAMETER); |
| 75 | this.survivedGenerationsNode = this.outputInformation.addChild("Survived Generations: " + this.currentlyReachedMaxNumberOfIterations + "/" + this.minimumIterationsToSurvive, NodeType.PARAMETER); |
| 76 | |
| 77 | if(this.mode == EvaluationMode.EXACT_NUMBER){ |
| 78 | this.survivorsNode = this.outputInformation.addChild("Survivors: " + this.numberOfIndividualsThatHasRemainedOptimalTheLongest + "/" + this.minimumSurvivors, NodeType.PARAMETER); |
| 79 | }else{ |
| 80 | this.survivorsNode = this.outputInformation.addChild("Survivors: " + (double)this.numberOfIndividualsThatHasRemainedOptimalTheLongest/archive.size()*100 + "%/" + this.minimumSurvivorsInPercentage*100 + "%", NodeType.PARAMETER); |
| 81 | } |
| 82 | this.outputInformation.getChildren().add(this.suggestedStop); |
| 83 | } |
| 84 | |
| 85 | /** |
| 86 | * {@inheritDoc} |
| 87 | * Implements the Pareto Optimal Set Stability Criterion: This criterion evaluates how many candidates |
| 88 | * have remained pareto optimal and for how many iterations. If the numbers reach the supplied requirements |
| 89 | * this criterion decides that the spareto optimal set is stable enough and probably would not change in the near future. |
| 90 | * And therefore suggests the termination of the optimization. |
| 91 | */ |
| 92 | @Override |
| 93 | public void evaluateImpl(int iteration, long currentTime) { |
| 94 | for(Individual indi : archive){ |
| 95 | if(this.survivalsCounter.containsKey(indi)){ |
| 96 | this.survivalsCounter.get(indi).renewSurvivalStatus(iteration); |
| 97 | }else{ |
| 98 | this.survivalsCounter.put(indi, new IndividualStatistics(iteration)); |
| 99 | } |
| 100 | } |
| 101 | |
| 102 | //Select the objects to delete |
| 103 | |
| 104 | List<Individual> individualsToRemove = new LinkedList<Individual>(); |
| 105 | |
| 106 | for(Map.Entry<Individual, IndividualStatistics> mapEntry : this.survivalsCounter.entrySet()){ |
| 107 | if(!mapEntry.getValue().hasSurvived(iteration)){ |
| 108 | individualsToRemove.add(mapEntry.getKey()); |
| 109 | } |
| 110 | } |
| 111 | |
| 112 | //Delete these objects |
| 113 | |
| 114 | for(Individual i : individualsToRemove){ |
| 115 | this.survivalsCounter.remove(i); |
| 116 | } |
| 117 | |
| 118 | //Count the survivors |
| 119 | |
| 120 | this.currentlyReachedMaxNumberOfIterations = 0; |
| 121 | this.numberOfIndividualsThatHasRemainedOptimalTheLongest = 0; |
| 122 | |
| 123 | for(IndividualStatistics iStat : this.survivalsCounter.values()){ |
| 124 | //Has the currently highest generation number reached the required minimum |
| 125 | if(this.currentlyReachedMaxNumberOfIterations == this.minimumIterationsToSurvive){ |
| 126 | if(iStat.getNumberOfSurvivedGenerations() >= this.minimumIterationsToSurvive){ |
| 127 | this.numberOfIndividualsThatHasRemainedOptimalTheLongest++; |
| 128 | } |
| 129 | }else{ |
| 130 | //Currently reached Generation number is lower than the required minimum |
| 131 | if(iStat.getNumberOfSurvivedGenerations() > this.currentlyReachedMaxNumberOfIterations){ |
| 132 | this.numberOfIndividualsThatHasRemainedOptimalTheLongest = 1; |
| 133 | this.currentlyReachedMaxNumberOfIterations = iStat.getNumberOfSurvivedGenerations(); |
| 134 | if(this.currentlyReachedMaxNumberOfIterations > this.minimumIterationsToSurvive){ |
| 135 | this.currentlyReachedMaxNumberOfIterations = this.minimumIterationsToSurvive; |
| 136 | } |
| 137 | }else if(iStat.getNumberOfSurvivedGenerations() == this.currentlyReachedMaxNumberOfIterations){ |
| 138 | this.numberOfIndividualsThatHasRemainedOptimalTheLongest++; |
| 139 | } |
| 140 | } |
| 141 | |
| 142 | } |
| 143 | |
| 144 | //Make the decision based on the mode |
| 145 | if(this.currentlyReachedMaxNumberOfIterations == this.minimumIterationsToSurvive && |
| 146 | ((this.mode == EvaluationMode.EXACT_NUMBER && this.numberOfIndividualsThatHasRemainedOptimalTheLongest >= this.minimumSurvivors) || |
| 147 | (this.mode == EvaluationMode.PERCENTAGE && (double)this.numberOfIndividualsThatHasRemainedOptimalTheLongest/this.archive.size() >= this.minimumSurvivorsInPercentage))){ |
| 148 | this.evaluationResult = true; |
| 149 | }else{ |
| 150 | this.evaluationResult = false; |
| 151 | } |
| 152 | } |
| 153 | |
| 154 | /** |
| 155 | * {@inheritDoc} |
| 156 | */ |
| 157 | @Override |
| 158 | public void updateOutputInformation() { |
| 159 | this.survivedGenerationsNode.updateValue("Survived Generations: " + this.currentlyReachedMaxNumberOfIterations + "/" + this.minimumIterationsToSurvive); |
| 160 | if(this.mode == EvaluationMode.EXACT_NUMBER){ |
| 161 | this.survivorsNode.updateValue("Survivors: " + this.numberOfIndividualsThatHasRemainedOptimalTheLongest + "/" + this.minimumSurvivors); |
| 162 | }else{ |
| 163 | this.survivorsNode.updateValue("Survivors: " + (double)this.numberOfIndividualsThatHasRemainedOptimalTheLongest/this.archive.size()*100 + "%/" + this.minimumSurvivorsInPercentage*100 + "%"); |
| 164 | } |
| 165 | } |
| 166 | |
| 167 | /** |
| 168 | * A helper class for storing individuals survival information. |
| 169 | * @author Atanas Dimitrov |
| 170 | */ |
| 171 | private class IndividualStatistics{ |
| 172 | private int survivedGenerations; |
| 173 | private int lastUpdated; |
| 174 | |
| 175 | public IndividualStatistics(int generationNumber){ |
| 176 | this.survivedGenerations = 1; |
| 177 | this.lastUpdated = generationNumber; |
| 178 | } |
| 179 | |
| 180 | /** |
| 181 | * Automatically updates the complete statistic for the individual in question. |
| 182 | * @param generationNumber |
| 183 | */ |
| 184 | public void renewSurvivalStatus(int generationNumber){ |
| 185 | this.survivedGenerations++; |
| 186 | this.lastUpdated = generationNumber; |
| 187 | } |
| 188 | |
| 189 | /** |
| 190 | * Answer whether the individual has survived the supplied iteration. |
| 191 | * @param iterationNumber - number if the iteration |
| 192 | * @return true if the individual has survived the iteration |
| 193 | */ |
| 194 | public boolean hasSurvived(int iterationNumber){ |
| 195 | return (this.lastUpdated >= iterationNumber); |
| 196 | } |
| 197 | |
| 198 | /** |
| 199 | * Return the number of the survived iterations for the individual |
| 200 | * @return the number of the survived iterations for the individual |
| 201 | */ |
| 202 | public int getNumberOfSurvivedGenerations(){ |
| 203 | return this.survivedGenerations; |
| 204 | } |
| 205 | } |
| 206 | |
| 207 | } |