[927] | 1 | // Copyright 2012 Georg-August-Universität Göttingen, Germany |
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| 2 | // |
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| 3 | // Licensed under the Apache License, Version 2.0 (the "License"); |
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| 4 | // you may not use this file except in compliance with the License. |
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| 5 | // You may obtain a copy of the License at |
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| 6 | // |
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| 7 | // http://www.apache.org/licenses/LICENSE-2.0 |
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| 8 | // |
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| 9 | // Unless required by applicable law or agreed to in writing, software |
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| 10 | // distributed under the License is distributed on an "AS IS" BASIS, |
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| 11 | // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
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| 12 | // See the License for the specific language governing permissions and |
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| 13 | // limitations under the License. |
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| 14 | |
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[922] | 15 | package de.ugoe.cs.autoquest.testgeneration; |
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[523] | 16 | |
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| 17 | import java.util.Collection; |
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| 18 | import java.util.HashSet; |
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| 19 | import java.util.List; |
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| 20 | import java.util.Set; |
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| 21 | |
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[922] | 22 | import de.ugoe.cs.autoquest.eventcore.Event; |
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| 23 | import de.ugoe.cs.autoquest.usageprofiles.IStochasticProcess; |
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[523] | 24 | |
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| 25 | /** |
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| 26 | * <p> |
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| 27 | * Generates a test suite by randomly walking an {@link IStochasticProcess}. |
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| 28 | * </p> |
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| 29 | * |
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| 30 | * @author Steffen Herbold |
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| 31 | * @version 1.0 |
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| 32 | */ |
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| 33 | public class RandomWalkGenerator { |
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| 34 | |
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[559] | 35 | /** |
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| 36 | * <p> |
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| 37 | * Number of sequences in the test suite. |
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| 38 | * </p> |
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| 39 | */ |
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| 40 | private final int numSequences; |
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[523] | 41 | |
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[559] | 42 | /** |
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| 43 | * <p> |
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| 44 | * Minimal length of a test sequence. |
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| 45 | * </p> |
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| 46 | */ |
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| 47 | private final int minLength; |
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[523] | 48 | |
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[559] | 49 | /** |
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| 50 | * <p> |
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| 51 | * Maximal length of a test sequence. |
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| 52 | * </p> |
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| 53 | */ |
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| 54 | private final int maxLength; |
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[523] | 55 | |
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[559] | 56 | /** |
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| 57 | * <p> |
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| 58 | * In case this member is true, only test cases that end in the global end event |
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| 59 | * {@link Event#ENDEVENT} are generated. If it is false, the end event can be any event. |
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| 60 | * </p> |
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| 61 | */ |
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| 62 | private final boolean validEnd; |
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[523] | 63 | |
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[559] | 64 | /** |
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| 65 | * <p> |
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| 66 | * Maximal number of random walks performed before aborting the test case generation and |
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| 67 | * returning a test suite with less than {@link #numSequences} test cases. This can happen if |
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| 68 | * too many generated random walks have to be discarded because their length is not between |
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| 69 | * {@link #minLength} and {@link #maxLength}. |
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| 70 | * </p> |
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| 71 | */ |
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| 72 | private final long maxIter; |
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[523] | 73 | |
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[559] | 74 | /** |
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| 75 | * <p> |
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[2026] | 76 | * Maximal number of attempts for creating a valid sequence. If this value is reached, the |
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| 77 | * sequence generation will be aborted. |
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| 78 | * </p> |
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| 79 | */ |
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| 80 | private final long maxIterValidSequence; |
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| 81 | |
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| 82 | /** |
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| 83 | * <p> |
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[559] | 84 | * Actual number of random walks performed to generate the test suite. |
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| 85 | * </p> |
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| 86 | */ |
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| 87 | private long actualIter = -1; |
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[523] | 88 | |
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[559] | 89 | /** |
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| 90 | * <p> |
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| 91 | * Constructor. Creates a new RandomWalkGenerator and ensures the validity of the parameters: |
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[2218] | 92 | * </p> |
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[559] | 93 | * <ul> |
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| 94 | * <li>numSequences must at least be 1 |
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| 95 | * <li>maxLength must at least be 1 |
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| 96 | * <li>minLength must be less than or equal to maxLength |
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| 97 | * <li>maxIter must be greater than or equal to numSequences |
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| 98 | * </ul> |
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[2218] | 99 | * <p> |
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[766] | 100 | * If one of these conditions is violated an {@link IllegalArgumentException} is thrown. |
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[559] | 101 | * </p> |
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| 102 | * |
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| 103 | * @param numSequences |
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| 104 | * number of sequences desired for the test suite |
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| 105 | * @param minLength |
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| 106 | * minimal length of a test sequence |
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| 107 | * @param maxLength |
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| 108 | * maximal length of a test sequence |
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| 109 | * @param validEnd |
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| 110 | * defines if test cases have to end with the global end event {@link Event#ENDEVENT} |
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| 111 | * (see {@link #validEnd}) |
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| 112 | * @param maxIter |
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| 113 | * maximal number of random walks before aborting the test case generation (see |
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| 114 | * {@link #maxIter}) |
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[2026] | 115 | * @param maxIterValidSequence |
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| 116 | * maximal number of attempts to create a valid sequence within the given restrictions |
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[559] | 117 | */ |
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| 118 | public RandomWalkGenerator(int numSequences, |
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| 119 | int minLength, |
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| 120 | int maxLength, |
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| 121 | boolean validEnd, |
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[2026] | 122 | long maxIter, |
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| 123 | long maxIterValidSequence) |
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[559] | 124 | { |
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| 125 | // check validity of the parameters |
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| 126 | if (numSequences < 1) { |
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[766] | 127 | throw new IllegalArgumentException("number of sequences must be at least 1 but is " + |
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[559] | 128 | numSequences); |
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| 129 | } |
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| 130 | if (maxLength < 1) { |
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[766] | 131 | throw new IllegalArgumentException( |
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[2026] | 132 | "maximal allowed length of test cases must be at least 1 but is " + |
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| 133 | maxLength); |
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[559] | 134 | } |
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| 135 | if (minLength > maxLength) { |
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[766] | 136 | throw new IllegalArgumentException( |
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[2026] | 137 | "minimal allowed length of test cases must be less than or equal to the maximal allowed length (min length: " + |
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| 138 | minLength + " ; max length: " + maxLength + ")"); |
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[559] | 139 | } |
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| 140 | if (maxIter < numSequences) { |
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[766] | 141 | throw new IllegalArgumentException( |
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[2026] | 142 | "maximal number of iterations must greater than or equal to the number of sequences (number of sequences: " + |
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| 143 | numSequences + |
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| 144 | " ; max iterations: " + |
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| 145 | maxIter + |
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| 146 | ")"); |
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[559] | 147 | } |
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[2026] | 148 | if( maxIterValidSequence < 1) { |
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| 149 | throw new IllegalArgumentException("maximal number of attempts to get a valid sequence must be positive, but is: " + maxIterValidSequence); |
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| 150 | } |
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[559] | 151 | this.numSequences = numSequences; |
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| 152 | this.minLength = minLength; |
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| 153 | this.maxLength = maxLength; |
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| 154 | this.validEnd = validEnd; |
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| 155 | this.maxIter = maxIter; |
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[2026] | 156 | this.maxIterValidSequence = maxIterValidSequence; |
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[559] | 157 | } |
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[523] | 158 | |
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[559] | 159 | /** |
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| 160 | * <p> |
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| 161 | * Generates a test suite by repeatedly randomly walking a stochastic process. |
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| 162 | * </p> |
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| 163 | * |
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| 164 | * @param model |
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| 165 | * stochastic process which performs the random walks |
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| 166 | * @return the test suite |
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| 167 | */ |
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| 168 | public Collection<List<Event>> generateTestSuite(IStochasticProcess model) { |
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| 169 | if (model == null) { |
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[766] | 170 | throw new IllegalArgumentException("model must not be null!"); |
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[559] | 171 | } |
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[523] | 172 | |
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[559] | 173 | Set<List<Event>> sequences = new HashSet<List<Event>>(numSequences); |
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| 174 | actualIter = 0; |
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| 175 | while (sequences.size() < numSequences && actualIter < maxIter) { |
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[2026] | 176 | List<Event> generatedSequence = model.randomSequence(maxLength, validEnd, maxIterValidSequence); |
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[559] | 177 | if (generatedSequence.size() >= minLength && generatedSequence.size() <= maxLength) { |
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| 178 | ((List<Event>) generatedSequence).add(0, Event.STARTEVENT); |
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| 179 | if (validEnd) { |
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| 180 | ((List<Event>) generatedSequence).add(Event.ENDEVENT); |
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| 181 | } |
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| 182 | sequences.add(generatedSequence); |
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| 183 | } |
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| 184 | actualIter++; |
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| 185 | } |
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[523] | 186 | |
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[559] | 187 | return sequences; |
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| 188 | } |
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[523] | 189 | |
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[559] | 190 | /** |
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| 191 | * <p> |
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| 192 | * Returns the actual number of random walks performed during the last call of |
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| 193 | * {@link #generateTestSuite(IStochasticProcess)} or -1 if |
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| 194 | * {@link #generateTestSuite(IStochasticProcess)} has not been called yet. |
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| 195 | * </p> |
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| 196 | * |
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| 197 | * @return actual number of random walks or -1 if {@link #generateTestSuite(IStochasticProcess)} |
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| 198 | * has not been called |
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| 199 | */ |
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| 200 | public long getActualIter() { |
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| 201 | return actualIter; |
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| 202 | } |
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[523] | 203 | } |
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