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diff --git a/watchmaker/framework/src/java/main/org/uncommons/watchmaker/framework/termination/Stagnation.java b/watchmaker/framework/src/java/main/org/uncommons/watchmaker/framework/termination/Stagnation.java
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+++ b/watchmaker/framework/src/java/main/org/uncommons/watchmaker/framework/termination/Stagnation.java
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+//=============================================================================
+// Copyright 2006-2010 Daniel W. Dyer
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//=============================================================================
+package org.uncommons.watchmaker.framework.termination;
+
+import org.uncommons.watchmaker.framework.PopulationData;
+import org.uncommons.watchmaker.framework.TerminationCondition;
+
+/**
+ * A {@link TerminationCondition} that halts evolution if no improvement in fitness
+ * is observed within a specified number of generations.
+ * @author Daniel Dyer
+ */
+public class Stagnation implements TerminationCondition
+{
+    private final int generationLimit;
+    private final boolean naturalFitness;
+    private final boolean usePopulationAverage;
+
+    private double bestFitness;
+    private int fittestGeneration;
+
+    /**
+     * Creates a {@link TerminationCondition} that will halt evolution after the
+     * specified number of generations passes without any improvement in the population's
+     * fittest individual.
+     * @param generationLimit The number of generations without improvement that
+     * will lead to termination.
+     * @param naturalFitness True if higher fitness scores are better, false otherwise.
+     */
+    public Stagnation(int generationLimit,
+                      boolean naturalFitness)
+    {
+        this(generationLimit, naturalFitness, false);
+    }
+
+
+    /**
+     * Creates a {@link TerminationCondition} that will halt evolution after the
+     * specified number of generations passes without any improvement in the population's
+     * fitness (either the fittest individual or the mean fitness of the entire population,
+     * depending on the final parameter).
+     * @param generationLimit The number of generations without improvement that
+     * will lead to termination.
+     * @param naturalFitness True if higher fitness scores are better, false otherwise.
+     * @param usePopulationAverage If true uses the mean fitness of the population as the
+     * criteria, otherwise uses the fittest individual.
+     */
+    public Stagnation(int generationLimit,
+                      boolean naturalFitness,
+                      boolean usePopulationAverage)
+    {
+        this.generationLimit = generationLimit;
+        this.naturalFitness = naturalFitness;
+        this.usePopulationAverage = usePopulationAverage;
+    }
+
+
+    /**
+     * {@inheritDoc}
+     */
+    public boolean shouldTerminate(PopulationData<?> populationData)
+    {
+        double fitness = getFitness(populationData);
+        if (populationData.getGenerationNumber() == 0 || hasFitnessImproved(fitness))
+        {
+            bestFitness = fitness;
+            fittestGeneration = populationData.getGenerationNumber();
+        }
+
+        return populationData.getGenerationNumber() - fittestGeneration >= generationLimit;
+    }
+
+
+    /**
+     * Determines the fitness of the current population (either best fitness or
+     * mean fitness depending on how the termination condition is configured).
+     * @param populationData Data about the current generation.
+     * @return The fitness measure used to decide whether the evolution has stagnated
+     * or not.
+     */
+    private double getFitness(PopulationData<?> populationData)
+    {
+        return usePopulationAverage
+               ? populationData.getMeanFitness()
+               : populationData.getBestCandidateFitness();
+    }
+
+
+    /**
+     * Determine whether the population fitness is better than the best seen so far.
+     * @param fitness The fitness of the current population (either best fitness or mean
+     * fitness depending on how the termination condition is configured).
+     * @return True if the fitness has improved in the current generation, false otherwise.
+     */
+    private boolean hasFitnessImproved(double fitness)
+    {
+        return (naturalFitness && fitness > bestFitness)
+            || (!naturalFitness && fitness < bestFitness);
+    }
+}