| 1 | package de.uka.ipd.sdq.simucomframework.variables.cache; |
| 2 | |
| 3 | import java.util.Collection; |
| 4 | import java.util.Collections; |
| 5 | import java.util.HashMap; |
| 6 | import java.util.Iterator; |
| 7 | |
| 8 | import org.apache.log4j.Logger; |
| 9 | import org.eclipse.emf.common.util.EList; |
| 10 | import org.eclipse.emf.ecore.EObject; |
| 11 | import org.eclipse.emf.ecore.util.EcoreUtil; |
| 12 | |
| 13 | import de.uka.ipd.sdq.probfunction.BoxedPDF; |
| 14 | import de.uka.ipd.sdq.probfunction.ContinuousSample; |
| 15 | import de.uka.ipd.sdq.probfunction.ProbabilityMassFunction; |
| 16 | import de.uka.ipd.sdq.probfunction.Sample; |
| 17 | import de.uka.ipd.sdq.probfunction.math.IProbabilityDensityFunction; |
| 18 | import de.uka.ipd.sdq.probfunction.math.IProbabilityFunction; |
| 19 | import de.uka.ipd.sdq.probfunction.math.IProbabilityFunctionFactory; |
| 20 | import de.uka.ipd.sdq.probfunction.math.IProbabilityMassFunction; |
| 21 | import de.uka.ipd.sdq.probfunction.print.ProbFunctionPrettyPrint; |
| 22 | import de.uka.ipd.sdq.probfunction.util.ProbfunctionSwitch; |
| 23 | import de.uka.ipd.sdq.stoex.Expression; |
| 24 | |
| 25 | /** |
| 26 | * A cache for Probability Functions. This saves the time to calculate the |
| 27 | * inverse commulative distribution function every time again |
| 28 | * @author Steffen Becker |
| 29 | * |
| 30 | */ |
| 31 | public class ProbFunctionCache { |
| 32 | private static Logger logger = |
| 33 | Logger.getLogger(ProbFunctionCache.class.getName()); |
| 34 | |
| 35 | private HashMap<EObject,IProbabilityFunction> probFunctions = new HashMap<EObject,IProbabilityFunction>(); |
| 36 | |
| 37 | /** |
| 38 | * Polymorphic switch to analyse and store probability functions |
| 39 | */ |
| 40 | private ProbfunctionSwitch<Object> probFunctionAnnotator = new ProbfunctionSwitch<Object>() { |
| 41 | @Override |
| 42 | public Object caseBoxedPDF(BoxedPDF object) { |
| 43 | adjustPDF(object); |
| 44 | IProbabilityDensityFunction pdf = null; |
| 45 | try { |
| 46 | pdf = IProbabilityFunctionFactory.eINSTANCE.transformToPDF(object); |
| 47 | pdf.checkConstrains(); |
| 48 | } catch(Exception ex) { |
| 49 | RuntimeException ex2 = new RuntimeException("PDF not valid: "+new ProbFunctionPrettyPrint().doSwitch(object)+". Caused by "+ex.getMessage(), ex); |
| 50 | logger.error("PMF not valid!", ex2); |
| 51 | throw ex2; |
| 52 | } |
| 53 | probFunctions.put(object, pdf); |
| 54 | return super.caseBoxedPDF(object); |
| 55 | } |
| 56 | |
| 57 | private void adjustPDF(BoxedPDF object) { |
| 58 | // Adjust PDFs which do not sum up to 1. Issue a warning if needed |
| 59 | EList<ContinuousSample> samples = object.getSamples(); |
| 60 | double sum = 0; |
| 61 | for(ContinuousSample sample : samples) { |
| 62 | sum += sample.getProbability(); |
| 63 | } |
| 64 | if (Math.abs(sum - 1) > 10e-10 ){ |
| 65 | //Get the problematic PDF as a string so the user can find it. |
| 66 | String sampleString = "...PDF["; |
| 67 | for (ContinuousSample continuousSample : samples) { |
| 68 | sampleString += "("+continuousSample.getValue()+";"+continuousSample.getProbability()+")"; |
| 69 | } |
| 70 | sampleString += "]"; |
| 71 | |
| 72 | // Adjust wrong PDFs |
| 73 | double delta = (1 - sum) / countNonZeroContiniousSamples(samples); |
| 74 | for(ContinuousSample sample : samples) { |
| 75 | if (sample.getProbability() > 0) |
| 76 | sample.setProbability(sample.getProbability()+delta); |
| 77 | } |
| 78 | |
| 79 | String sampleStringNew = "...PDF["; |
| 80 | for (ContinuousSample continuousSample : samples) { |
| 81 | sampleStringNew += "("+continuousSample.getValue()+";"+continuousSample.getProbability()+")"; |
| 82 | } |
| 83 | sampleStringNew += "]"; |
| 84 | |
| 85 | logger.warn("Probfunction needed adjustment as it didn't sum up to 1! Fix your input specification!! Was: "+sampleString+", now is: "+sampleStringNew); |
| 86 | } |
| 87 | |
| 88 | } |
| 89 | |
| 90 | private double countNonZeroContiniousSamples(EList<ContinuousSample> samples) { |
| 91 | int count=0; |
| 92 | for (ContinuousSample s : samples) |
| 93 | if (s.getProbability()>0) |
| 94 | count++; |
| 95 | return count; |
| 96 | } |
| 97 | |
| 98 | private double countNonZeroSamples(EList<Sample> samples) { |
| 99 | int count=0; |
| 100 | for (Sample s : samples) |
| 101 | if (s.getProbability()>0) |
| 102 | count++; |
| 103 | return count; |
| 104 | } |
| 105 | |
| 106 | @Override |
| 107 | public Object caseProbabilityMassFunction(ProbabilityMassFunction object) { |
| 108 | adjustPMF(object); |
| 109 | |
| 110 | IProbabilityMassFunction pmf = IProbabilityFunctionFactory.eINSTANCE.transformToPMF(object); |
| 111 | try { |
| 112 | pmf.checkConstrains(); |
| 113 | } catch(Exception ex) { |
| 114 | RuntimeException ex2 = new RuntimeException("PMF not valid: "+new ProbFunctionPrettyPrint().doSwitch(object), ex); |
| 115 | logger.error("PMF not valid!", ex2); |
| 116 | throw ex2; |
| 117 | } |
| 118 | probFunctions.put(object, pmf); |
| 119 | return super.caseProbabilityMassFunction(object); |
| 120 | } |
| 121 | |
| 122 | private void adjustPMF(ProbabilityMassFunction object) { |
| 123 | // Adjust wrong PMFs |
| 124 | EList<Sample> samples = object.getSamples(); |
| 125 | double sum = 0; |
| 126 | for(Sample sample : (Collection<Sample>)samples) { |
| 127 | sum += sample.getProbability(); |
| 128 | } |
| 129 | if (Math.abs(sum - 1) > 10e-10 ){ |
| 130 | double delta = (1 - sum) / countNonZeroSamples(samples); |
| 131 | for(Sample sample : (Collection<Sample>)samples) { |
| 132 | if (sample.getProbability() > 0) |
| 133 | sample.setProbability(sample.getProbability()+delta); |
| 134 | } |
| 135 | logger.warn("Probfunction needed adjustment as it didn't sum up to 1! Fix your input specification!!"); |
| 136 | } |
| 137 | } |
| 138 | }; |
| 139 | |
| 140 | |
| 141 | /** |
| 142 | * Initialise the probfunctition cache for all probfunctions in the |
| 143 | * given expression. A visitor is used to search for and cache all |
| 144 | * probfuntions |
| 145 | * @param ex The stoex to analyse |
| 146 | */ |
| 147 | public ProbFunctionCache(Expression ex) { |
| 148 | for (Iterator<EObject> it=EcoreUtil.getAllContents(Collections.singleton(ex)); |
| 149 | it.hasNext(); ) { |
| 150 | probFunctionAnnotator.doSwitch(it.next()); |
| 151 | } |
| 152 | } |
| 153 | |
| 154 | |
| 155 | /** |
| 156 | * Return the cached probfuntion for partial expression e |
| 157 | * @param e SubExpession which has to be a probfunction literal for |
| 158 | * which to query the cache |
| 159 | * @return Cached probfunction |
| 160 | */ |
| 161 | public IProbabilityFunction getProbFunction(EObject e) { |
| 162 | assert probFunctions.containsKey(e); |
| 163 | return probFunctions.get(e); |
| 164 | } |
| 165 | } |