private HashMap<Integer, Set<Integer>> createVesselDepartureChromosome(
HashMap<Integer, Set<Integer>> installationDepartureChromosome) {
HashMap<Integer, Set<Integer>> individualVesselDeparturePatterns =
new HashMap<Integer, Set<Integer>>();
Set<Integer> daysWithDeparture =
getDaysWithDeparture(
installationDepartureChromosome); // get all days that installations require a departure
for (Vessel vessel :
problemData
.getVessels()) { // for each vessel, choose a random vessel pattern that fits with the
// installationDepartureChromosome
Set<Integer> randomVesselDeparturePattern =
pickRandomVesselDeparturePattern(daysWithDeparture, individualVesselDeparturePatterns);
if (randomVesselDeparturePattern == null) { // workaround until a smarter heuristic is created
numberOfPatternRestarts++;
return createVesselDepartureChromosome(installationDepartureChromosome);
}
individualVesselDeparturePatterns.put(vessel.getNumber(), randomVesselDeparturePattern);
}
if (isDepotConstraintViolated(individualVesselDeparturePatterns)) {
numberOfDepotRestarts++;
return createVesselDepartureChromosome(installationDepartureChromosome);
}
return individualVesselDeparturePatterns;
}
private int getAlreadyVisitedDaysAvailable(
HashMap<Integer, Set<Integer>> individualVesselDeparturePatterns,
Set<Integer> unvisitedDays) {
int vesselsLeft =
problemData.getVessels().size()
- individualVesselDeparturePatterns.keySet().size(); // number of unchartered vessels
int maxDeparturesInPattern =
Collections.max(
problemData
.getVesselDeparturePatterns()
.keySet()); // the maximum number of departures found in any vessel pattern
int alreadyVisitedDaysAvailable =
(vesselsLeft * maxDeparturesInPattern
- unvisitedDays
.size()); // if there is 1 unchartered vessel and the patterns have maximum 3
// departures and there are 2 days without departures, at most 1*3 - 2 = 1
// day that already has a departure can be part of the new pattern
return alreadyVisitedDaysAvailable;
}
private HashMap<Integer, HashMap<Integer, ArrayList<Integer>>> createGiantTourChromosome(
HashMap<Integer, Set<Integer>> installationDepartureChromosome,
HashMap<Integer, Set<Integer>> vesselDepartureChromosome) {
HashMap<Integer, Set<Integer>> reversedInstallationChromosome =
Utilities.getReversedHashMap(
installationDepartureChromosome); // the key is a period/day and the Set<Integer> is a
// set of installation numbers
HashMap<Integer, Set<Integer>> reversedVesselChromosome =
Utilities.getReversedHashMap(
vesselDepartureChromosome); // the key is a period/day, and the Set<Integer> is a set of
// vessel numbers
int nDays = problemData.getLengthOfPlanningPeriod();
int nVessels = problemData.getVessels().size();
// initializing
HashMap<Integer, HashMap<Integer, ArrayList<Integer>>> giantTourChromosome =
GenotypeHGS.generateEmptyGiantTourChromosome(nDays, nVessels);
// allocating
for (Integer day : reversedInstallationChromosome.keySet()) {
Set<Integer> installationsToAllocate = reversedInstallationChromosome.get(day);
Set<Integer> availableVessels = reversedVesselChromosome.get(day);
HashMap<Integer, ArrayList<Integer>> vesselAllocations = giantTourChromosome.get(day);
for (Integer installation : installationsToAllocate) {
Integer randomVessel = Utilities.pickRandomElementFromSet(availableVessels);
ArrayList<Integer> existingInstallations = vesselAllocations.get(randomVessel);
existingInstallations.add(installation);
vesselAllocations.put(randomVessel, existingInstallations);
}
giantTourChromosome.put(day, vesselAllocations);
}
// shuffle sequence of visits
for (Integer day : giantTourChromosome.keySet()) {
for (Integer vessel : giantTourChromosome.get(day).keySet()) {
ArrayList<Integer> installationsToVisit = giantTourChromosome.get(day).get(vessel);
Collections.shuffle(installationsToVisit);
}
}
return giantTourChromosome;
}