/** Created by schroeder on 16/01/15. */
class InsertionNoiseMaker implements SoftActivityConstraint, IterationStartsListener {
private final double noiseProbability;
private boolean makeNoise = false;
private double noiseLevel = 0.1;
private Random random = RandomNumberGeneration.newInstance();
// private Random[] randomArray;
private double maxCosts;
InsertionNoiseMaker(
VehicleRoutingProblem vrp, double maxCosts, double noiseLevel, double noiseProbability) {
this.noiseLevel = noiseLevel;
this.noiseProbability = noiseProbability;
this.maxCosts = maxCosts;
// randomArray = new Random[vrp.getNuActivities() + 2];
// for (int i = 0; i < randomArray.length; i++) {
// Random r = new Random();
// r.setSeed(random.nextLong());
// randomArray[i] = r;
// }
}
@Override
public void informIterationStarts(
int i, VehicleRoutingProblem problem, Collection<VehicleRoutingProblemSolution> solutions) {
if (random.nextDouble() < noiseProbability) {
makeNoise = true;
} else makeNoise = false;
}
@Override
public double getCosts(
JobInsertionContext iFacts,
TourActivity prevAct,
TourActivity newAct,
TourActivity nextAct,
double prevActDepTime) {
if (makeNoise) {
return noiseLevel * maxCosts * random.nextDouble();
}
return 0;
}
public void setRandom(Random random) {
this.random = random;
}
}
public class SearchStrategyManager {
private List<SearchStrategyListener> searchStrategyListeners =
new ArrayList<SearchStrategyListener>();
private List<SearchStrategy> strategies = new ArrayList<SearchStrategy>();
private List<Double> weights = new ArrayList<Double>();
private Map<String, Integer> id2index = new HashMap<String, Integer>();
private Random random = RandomNumberGeneration.getRandom();
private double sumWeights = 0;
private int strategyIndex = 0;
public void setRandom(Random random) {
this.random = random;
}
public List<SearchStrategy> getStrategies() {
return Collections.unmodifiableList(strategies);
}
/**
* Returns the probabilities. [schroeder (2014.11.21): Now they are actually no propabilities
* anymore but weights. The resulting probabilities are calculated here with the sum of weights]
*
* @return list of probabilities
*/
@Deprecated
public List<Double> getProbabilities() {
return Collections.unmodifiableList(weights);
}
public List<Double> getWeights() {
return Collections.unmodifiableList(weights);
}
public double getWeight(String strategyId) {
return weights.get(id2index.get(strategyId));
}
/**
* adds a new search strategy with a certain weight.
*
* @param strategy strategy to be added
* @param weight of corresponding strategy to be added
* @throws java.lang.IllegalStateException if strategy is null OR weight < 0
*/
public void addStrategy(SearchStrategy strategy, double weight) {
if (strategy == null) {
throw new IllegalStateException("strategy is null. make sure adding a valid strategy.");
}
if (id2index.keySet().contains(strategy.getId())) {
throw new IllegalStateException(
"strategyId "
+ strategy.getId()
+ " already in use. replace strateId in your config file or code with a unique strategy id");
}
if (weight < 0.0) {
throw new IllegalStateException("weight is lower than zero.");
}
id2index.put(strategy.getId(), strategyIndex);
strategyIndex++;
strategies.add(strategy);
weights.add(weight);
sumWeights += weight;
}
public void informStrategyWeightChanged(String strategyId, double weight) {
int strategyIndex = id2index.get(strategyId);
weights.set(strategyIndex, weight);
updateSumWeights();
}
private void updateSumWeights() {
double sum = 0.;
for (double w : weights) {
sum += w;
}
sumWeights = sum;
}
/**
* Returns search strategy that has been randomly selected.
*
* @return selected search strategy
* @throws java.lang.IllegalStateException if randomNumberGenerator is null OR no search strategy
* can be found
*/
public SearchStrategy getRandomStrategy() {
if (random == null)
throw new IllegalStateException(
"randomizer is null. make sure you set random object correctly");
double randomFig = random.nextDouble();
double sumProbabilities = 0.0;
for (int i = 0; i < weights.size(); i++) {
sumProbabilities += weights.get(i) / sumWeights;
if (randomFig < sumProbabilities) {
return strategies.get(i);
}
}
throw new IllegalStateException("no search-strategy found");
}
public void addSearchStrategyListener(SearchStrategyListener strategyListener) {
searchStrategyListeners.add(strategyListener);
}
public void addSearchStrategyModuleListener(SearchStrategyModuleListener moduleListener) {
for (SearchStrategy s : strategies) {
s.addModuleListener(moduleListener);
}
}
}