From 057f12869778ab82f0055ba2b9bf7ac12375edbc Mon Sep 17 00:00:00 2001
From: oblonski <4sschroeder@gmail.com>
Date: Sat, 10 May 2014 16:34:25 +0200
Subject: [PATCH] outsourced automatic threshold initialization from
 algorithm.acceptor.SchrimpfAcceptance to
 algorithm.acceptor.SchrimpfInitialThresholdGenerator

---
 .../SchrimpfInitialThresholdGenerator.java    | 72 ++++++++++++++++++-
 .../acceptor/SchrimpfAcceptanceTest.java      |  1 +
 2 files changed, 70 insertions(+), 3 deletions(-)

diff --git a/jsprit-core/src/main/java/jsprit/core/algorithm/acceptor/SchrimpfInitialThresholdGenerator.java b/jsprit-core/src/main/java/jsprit/core/algorithm/acceptor/SchrimpfInitialThresholdGenerator.java
index 4c452277..50b8f41e 100644
--- a/jsprit-core/src/main/java/jsprit/core/algorithm/acceptor/SchrimpfInitialThresholdGenerator.java
+++ b/jsprit-core/src/main/java/jsprit/core/algorithm/acceptor/SchrimpfInitialThresholdGenerator.java
@@ -1,9 +1,75 @@
 package jsprit.core.algorithm.acceptor;
 
-class SchrimpfInitialThresholdGenerator {
+import java.net.URL;
+import java.util.Collection;
+
+import org.apache.commons.math.stat.descriptive.moment.StandardDeviation;
+import org.apache.log4j.Logger;
+
+import jsprit.core.algorithm.VehicleRoutingAlgorithm;
+import jsprit.core.algorithm.io.AlgorithmConfig;
+import jsprit.core.algorithm.io.AlgorithmConfigXmlReader;
+import jsprit.core.algorithm.io.VehicleRoutingAlgorithms;
+import jsprit.core.algorithm.listener.AlgorithmStartsListener;
+import jsprit.core.algorithm.listener.IterationEndsListener;
+import jsprit.core.problem.VehicleRoutingProblem;
+import jsprit.core.problem.solution.VehicleRoutingProblemSolution;
+import jsprit.core.util.Resource;
+import jsprit.core.util.Solutions;
+
+public class SchrimpfInitialThresholdGenerator implements AlgorithmStartsListener {
 	
-	public double getInitialThreshold(){
-		return 0.0;
+	private static Logger logger = Logger.getLogger(SchrimpfInitialThresholdGenerator.class);
+	
+	private SchrimpfAcceptance schrimpfAcceptance;
+	
+	private int nOfRandomWalks;
+	
+	public SchrimpfInitialThresholdGenerator(SchrimpfAcceptance schrimpfAcceptance, int nOfRandomWalks) {
+		super();
+		this.schrimpfAcceptance = schrimpfAcceptance;
+		this.nOfRandomWalks = nOfRandomWalks;
+	}
+
+	@Override
+	public void informAlgorithmStarts(VehicleRoutingProblem problem,VehicleRoutingAlgorithm algorithm,Collection<VehicleRoutingProblemSolution> solutions) {
+		logger.info("---------------------------------------------------------------------");
+		logger.info("prepare schrimpfAcceptanceFunction, i.e. determine initial threshold");
+		logger.info("start random-walk (see randomWalk.xml)");
+		double now = System.currentTimeMillis();
+		
+		/*
+		 * randomWalk to determine standardDev
+		 */
+		final double[] results = new double[nOfRandomWalks];
+		
+		URL resource = Resource.getAsURL("randomWalk.xml");
+		AlgorithmConfig algorithmConfig = new AlgorithmConfig();
+		new AlgorithmConfigXmlReader(algorithmConfig).read(resource);
+		VehicleRoutingAlgorithm vra = VehicleRoutingAlgorithms.createAlgorithm(problem, algorithmConfig);
+		vra.setNuOfIterations(nOfRandomWalks);
+		vra.getAlgorithmListeners().addListener(new IterationEndsListener() {
+			
+			@Override
+			public void informIterationEnds(int iteration, VehicleRoutingProblem problem, Collection<VehicleRoutingProblemSolution> solutions) {
+				double result = Solutions.bestOf(solutions).getCost();
+//				logger.info("result="+result);
+				results[iteration-1] = result;
+			}
+			
+		});
+		vra.searchSolutions();
+		
+		StandardDeviation dev = new StandardDeviation();
+		double standardDeviation = dev.evaluate(results);
+		double initialThreshold = standardDeviation / 2;
+		
+		schrimpfAcceptance.setInitialThreshold(initialThreshold);
+		
+		logger.info("warmup done");
+		logger.info("total time: " + ((System.currentTimeMillis()-now)/1000.0) + "s");
+		logger.info("initial threshold: " + initialThreshold);
+		logger.info("---------------------------------------------------------------------");
 	}
 
 }
diff --git a/jsprit-core/src/test/java/jsprit/core/algorithm/acceptor/SchrimpfAcceptanceTest.java b/jsprit-core/src/test/java/jsprit/core/algorithm/acceptor/SchrimpfAcceptanceTest.java
index 4def40c4..e5fb0574 100644
--- a/jsprit-core/src/test/java/jsprit/core/algorithm/acceptor/SchrimpfAcceptanceTest.java
+++ b/jsprit-core/src/test/java/jsprit/core/algorithm/acceptor/SchrimpfAcceptanceTest.java
@@ -23,6 +23,7 @@ public class SchrimpfAcceptanceTest {
 		return when(mock(VehicleRoutingProblemSolution.class).getCost()).thenReturn(cost).getMock();
 	}
 
+	@SuppressWarnings("deprecation")
 	@Before
 	public void setup() {
 		schrimpfAcceptance = new SchrimpfAcceptance(1, 0.3, 100);