add and test new ruin strategy: RuinWorst

jsprit-core/src/main/java/jsprit/core/algorithm/ruin/RuinWorst.java

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+/*******************************************************************************
+ * Copyright (C) 2014  Stefan Schroeder
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 3.0 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public 
+ * License along with this library.  If not, see <http://www.gnu.org/licenses/>.
+ ******************************************************************************/
+package jsprit.core.algorithm.ruin;
+
+import jsprit.core.problem.VehicleRoutingProblem;
+import jsprit.core.problem.driver.DriverImpl;
+import jsprit.core.problem.job.Job;
+import jsprit.core.problem.solution.route.VehicleRoute;
+import jsprit.core.problem.solution.route.activity.TourActivity;
+import jsprit.core.problem.vehicle.Vehicle;
+import jsprit.core.util.NoiseMaker;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+import java.util.*;
+
+
+/**
+ * Ruin strategy that ruins current solution randomly. I.e.
+ * customer are removed randomly from current solution.
+ * 
+ * @author stefan schroeder
+ * 
+ */
+
+public final class RuinWorst extends AbstractRuinStrategy {
+
+	private Logger logger = LogManager.getLogger(RuinWorst.class);
+
+	private VehicleRoutingProblem vrp;
+
+	private NoiseMaker noiseMaker = new NoiseMaker(){
+
+		@Override
+		public double makeNoise() {
+			return 0;
+		}
+	};
+
+	public void setNoiseMaker(NoiseMaker noiseMaker) {
+		this.noiseMaker = noiseMaker;
+	}
+
+	public RuinWorst(VehicleRoutingProblem vrp, final int initialNumberJobsToRemove) {
+		super();
+		this.vrp = vrp;
+		setRuinShareFactory(new RuinShareFactory() {
+			@Override
+			public int createNumberToBeRemoved() {
+				return initialNumberJobsToRemove;
+			}
+		});
+        logger.info("initialise " + this);
+		logger.info("done");
+	}
+
+	/**
+	 * Removes a fraction of jobs from vehicleRoutes. 
+	 * 
+	 * <p>The number of jobs is calculated as follows: Math.ceil(vrp.getJobs().values().size() * fractionOfAllNodes2beRuined).
+	 */
+	@Override
+	public Collection<Job> ruinRoutes(Collection<VehicleRoute> vehicleRoutes) {
+        List<Job> unassignedJobs = new ArrayList<Job>();
+		int nOfJobs2BeRemoved = getRuinShareFactory().createNumberToBeRemoved();
+		ruin(vehicleRoutes, nOfJobs2BeRemoved, unassignedJobs);
+        return unassignedJobs;
+	}
+
+	/**
+	 * Removes nOfJobs2BeRemoved from vehicleRoutes, including targetJob.
+	 */
+	@Override
+	public Collection<Job> ruinRoutes(Collection<VehicleRoute> vehicleRoutes, Job targetJob, int nOfJobs2BeRemoved) {
+        throw new UnsupportedOperationException("ruinRoutes not supported");
+	}
+
+	private void ruin(Collection<VehicleRoute> vehicleRoutes, int nOfJobs2BeRemoved, List<Job> unassignedJobs) {
+		LinkedList<Job> availableJobs = new LinkedList<Job>(vrp.getJobs().values());
+		int toRemove = nOfJobs2BeRemoved;
+		while(toRemove > 0){
+			Job worst = getWorst(vehicleRoutes);
+			if(worst == null) break;
+			removeJob(worst,vehicleRoutes);
+			availableJobs.remove(worst);
+			unassignedJobs.add(worst);
+			toRemove--;
+		}
+	}
+
+	private Job getWorst(Collection<VehicleRoute> copied) {
+		Job worst = null;
+		double bestSavings = Double.MIN_VALUE;
+
+		for(VehicleRoute route : copied) {
+			if(route.isEmpty()) continue;
+			Map<Job,Double> savingsMap = new HashMap<Job,Double>();
+			TourActivity actBefore = route.getStart();
+			TourActivity actToEval = null;
+			for (TourActivity act : route.getActivities()) {
+				if (actToEval == null) {
+					actToEval = act;
+					continue;
+				}
+				double savings = savings(route, actBefore, actToEval, act);
+				Job job = ((TourActivity.JobActivity) actToEval).getJob();
+				if(!savingsMap.containsKey(job)){
+					savingsMap.put(job,savings);
+				}
+				else {
+					double s = savingsMap.get(job);
+					savingsMap.put(job,s+savings);
+				}
+				actBefore = actToEval;
+				actToEval = act;
+			}
+			double savings = savings(route, actBefore, actToEval, route.getEnd());
+			Job job = ((TourActivity.JobActivity) actToEval).getJob();
+			if(!savingsMap.containsKey(job)){
+				savingsMap.put(job,savings);
+			}
+			else {
+				double s = savingsMap.get(job);
+				savingsMap.put(job,s+savings);
+			}
+			//getCounts best
+			for(Job j : savingsMap.keySet()){
+				if(savingsMap.get(j) > bestSavings){
+					bestSavings = savingsMap.get(j);
+					worst = j;
+				}
+			}
+		}
+		return worst;
+	}
+
+	private double savings(VehicleRoute route, TourActivity actBefore, TourActivity actToEval, TourActivity act) {
+		double savings = c(actBefore, actToEval, route.getVehicle()) + c(actToEval, act, route.getVehicle()) - c(actBefore, act, route.getVehicle());
+		return Math.max(0,savings + noiseMaker.makeNoise());
+	}
+
+	private double c(TourActivity from, TourActivity to, Vehicle vehicle) {
+		return vrp.getTransportCosts().getTransportCost(from.getLocation(),to.getLocation(),from.getEndTime(), DriverImpl.noDriver(), vehicle);
+	}
+
+	@Override
+	public String toString() {
+		return "[name=worstRuin]";
+	}
+
+}

jsprit-core/src/main/java/jsprit/core/util/NoiseMaker.java

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+package jsprit.core.util;
+
+/**
+ * Created by schroeder on 16/01/15.
+ */
+public interface NoiseMaker {
+
+    public double makeNoise();
+
+}