rinde.sim.pdptw.gendreau06.Gendreau06ObjectiveFunction Maven / Gradle / Ivy
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/**
*
*/
package rinde.sim.pdptw.gendreau06;
import rinde.sim.pdptw.common.ObjectiveFunction;
import rinde.sim.pdptw.common.StatisticsDTO;
/**
* @author Rinde van Lon
*
*/
public class Gendreau06ObjectiveFunction implements ObjectiveFunction {
protected final double alpha;
protected final double beta;
public Gendreau06ObjectiveFunction() {
alpha = 1d;
beta = 1d;
}
/**
* All parcels need to be delivered, all vehicles need to be back at the
* depot.
*/
@Override
public boolean isValidResult(StatisticsDTO stats) {
return stats.totalParcels == stats.acceptedParcels
&& stats.totalParcels == stats.totalPickups
&& stats.totalParcels == stats.totalDeliveries && stats.simFinish
&& stats.totalVehicles == stats.vehiclesAtDepot;
}
/**
* Computes the cost according to the definition of the paper: the cost
* function used throughout this work is to minimize a weighted sum of three
* different criteria: total travel time, sum of lateness over all pick-up and
* delivery locations and sum of overtime over all vehicles. The function
* is defined as:
* sum(Tk) + alpha sum(max(0,tv-lv)) + beta sum(max(0,tk-l0))
* Where: Tk is the total travel time on route Rk, alpha and beta are
* weighting parameters which were set to 1 in the paper. The definition of
* lateness: max(0,lateness) is commonly referred to as
* tardiness. All times are expressed in minutes.
*
*/
@Override
public double computeCost(StatisticsDTO stats) {
final double totalTravelTime = travelTime(stats);
final double sumTardiness = tardiness(stats);
final double overTime = overTime(stats);
return totalTravelTime + (alpha * sumTardiness) + (beta * overTime);
}
@Override
public String printHumanReadableFormat(StatisticsDTO stats) {
return new StringBuilder().append("Travel time: ")
.append(travelTime(stats)).append("\nTardiness: ")
.append(tardiness(stats)).append("\nOvertime: ")
.append(overTime(stats)).append("\nTotal: ").append(computeCost(stats))
.toString();
}
// time in minutes
public double travelTime(StatisticsDTO stats) {
// avg speed is 30 km/h
// = (dist / 30.0) * 60.0
return stats.totalDistance * 2d;
}
public double tardiness(StatisticsDTO stats) {
return (stats.pickupTardiness + stats.deliveryTardiness) / 60000d;
}
public double overTime(StatisticsDTO stats) {
return stats.overTime / 60000d;
}
}