From 9dfcf4d71a1fd7b3d99fe4b8dd209e71742c0ac2 Mon Sep 17 00:00:00 2001
From: Marcel Kronfeld <makron@gmx.net>
Date: Thu, 27 Jan 2011 10:02:10 +0000
Subject: [PATCH] Additional integer mutation operator

---
 .../GAGIInitializeSegmentwise.java            |  24 +--
 .../go/operators/mutation/MutateGISubset.java | 164 ++++++++++++++++++
 2 files changed, 176 insertions(+), 12 deletions(-)
 create mode 100644 src/eva2/server/go/operators/mutation/MutateGISubset.java

diff --git a/src/eva2/server/go/operators/initialization/GAGIInitializeSegmentwise.java b/src/eva2/server/go/operators/initialization/GAGIInitializeSegmentwise.java
index ef201248..51eae204 100644
--- a/src/eva2/server/go/operators/initialization/GAGIInitializeSegmentwise.java
+++ b/src/eva2/server/go/operators/initialization/GAGIInitializeSegmentwise.java
@@ -10,11 +10,12 @@ import eva2.tools.EVAERROR;
 import eva2.tools.math.RNG;
 
 /**
- * An initialization method which sets a fixed number of specified values per segment,
+ * An initialization method which sets a fixed number of specified target elements per segment,
  * where a segment is a connected subsequence of the genotype.
  * This is usable for binary and integer individuals only.
- * For binary individuals, this allows to control the number of bits per segment. For
- * integer individuals, it allows to control the number of occurences of a certain integer
+ * For binary individuals, this allows to control the number of bits per segment by
+ * setting the target element to '1'. For
+ * integer individuals, it allows to control the number of occurrences of a certain integer
  * per segment. It may also be used to initialize with subsets of integers (by setting 0 
  * elements to a certain type and all to a subset of the range).
  * 
@@ -27,7 +28,6 @@ import eva2.tools.math.RNG;
  * has strict priority over the fixed cardinality definition.  
  * 
  * @author mkron
- *
  */
 public class GAGIInitializeSegmentwise implements InterfaceInitialization, java.io.Serializable {
 	private static final long serialVersionUID = 1L;
@@ -178,24 +178,24 @@ public class GAGIInitializeSegmentwise implements InterfaceInitialization, java.
 		else return (targetElement!=1);
 	}
 	
-	public int[] getBitsPerSegmentArray() {
+	public int[] getTargetElementsPerSegmentArray() {
 		return bitsPerSegmentArray;
 	}
-	public void setBitsPerSegmentArray(int[] bitsPerSegmentArray) {
+	public void setTargetElementsPerSegmentArray(int[] bitsPerSegmentArray) {
 		this.bitsPerSegmentArray = bitsPerSegmentArray;
 	}
-	public String bitsPerSegmentArrayTipText() {
-		return "A value per segment defining the number of bits to set for that segment, or null if fixed";
+	public String targetElementsPerSegmentArrayTipText() {
+		return "A value per segment defining the number of target elements to set for that segment, or null if fixed";
 	}
 
-	public int getBitsPerSegment() {
+	public int getTargetElementsPerSegment() {
 		return bitsPerSegment;
 	}
-	public void setBitsPerSegment(int bitsPerSegment) {
+	public void setTargetElementsPerSegment(int bitsPerSegment) {
 		this.bitsPerSegment = bitsPerSegment;
 	}
-	public String bitsPerSegmentTipText() {
-		return "If not array-wise defined, this fixed number of bits is set per segment";
+	public String targetElementsPerSegmentTipText() {
+		return "If not defined as an array, this fixed number of target elements is set per segment";
 	}
 
 	public int getSegmentLength() {
diff --git a/src/eva2/server/go/operators/mutation/MutateGISubset.java b/src/eva2/server/go/operators/mutation/MutateGISubset.java
new file mode 100644
index 00000000..f866da31
--- /dev/null
+++ b/src/eva2/server/go/operators/mutation/MutateGISubset.java
@@ -0,0 +1,164 @@
+package eva2.server.go.operators.mutation;
+
+import java.io.Serializable;
+
+import eva2.gui.BeanInspector;
+import eva2.server.go.individuals.AbstractEAIndividual;
+import eva2.server.go.individuals.InterfaceGIIndividual;
+import eva2.server.go.populations.Population;
+import eva2.server.go.problems.InterfaceOptimizationProblem;
+import eva2.tools.EVAERROR;
+import eva2.tools.math.RNG;
+
+/**
+ * An integer mutation operator which switches elements within a given subset only.
+ * 
+ * @author mkron
+ *
+ */
+public class MutateGISubset implements InterfaceMutation, Serializable {
+	private int[] mutableSet = new int[]{0,1};
+	private int minNumMutations = 1;
+	private int maxNumMutations = 3;
+	private boolean enforceMutablePositions = true;
+	
+	public MutateGISubset() {}
+	
+	public MutateGISubset(MutateGISubset o) {
+		this.minNumMutations = o.minNumMutations;
+		this.maxNumMutations = o.maxNumMutations;
+		this.enforceMutablePositions = o.enforceMutablePositions;
+		if (o.mutableSet!=null) {
+			this.mutableSet=new int[o.mutableSet.length];
+			System.arraycopy(o.mutableSet, 0, this.mutableSet, 0, o.mutableSet.length);
+		}
+	}
+	
+	public MutateGISubset(int[] muteSet, int minMutes, int maxMutes) {
+		setMutableSet(muteSet);
+		setMinNumMutations(minMutes);
+		setMaxNumMutations(maxMutes);
+	}
+	
+	public Object clone() {
+		return new MutateGISubset(this);
+	}
+	
+	public void crossoverOnStrategyParameters(AbstractEAIndividual indy1,
+			Population partners) {
+		// nothing to do
+	}
+
+	public String getStringRepresentation() {
+		return "GI subset mutation in " + BeanInspector.toString(mutableSet);
+	}
+
+	public void init(AbstractEAIndividual individual,
+			InterfaceOptimizationProblem opt) {
+		// nothing to do
+		
+	}
+
+	public void mutate(AbstractEAIndividual individual) {
+		if (individual instanceof InterfaceGIIndividual) {
+			InterfaceGIIndividual giIndy = (InterfaceGIIndividual)individual;
+			int[] genotype = giIndy.getIGenotype();
+			int[][] range = giIndy.getIntRange();
+			int numMutes=RNG.randomInt(minNumMutations, maxNumMutations);
+			for (int i=0; i<numMutes; i++) {
+				maybePerformSingleMutation(genotype, range, genotype.length/numMutes);
+			}
+		}
+	}
+
+	private void maybePerformSingleMutation(int[] genotype, int[][] range, int maxTries) {
+		int index=RNG.randomInt(genotype.length);
+		if (enforceMutablePositions && !(isMutable(genotype[index]))) {
+			// if the mutation event should be forced, search a mutable element with a max. no. tries
+			do {
+				index=RNG.randomInt(genotype.length);
+				maxTries--;
+			} while (maxTries>0 && (!isMutable(genotype[index])));
+		}
+		if (isMutable(genotype[index])) { // if it is in the mutable subset
+			genotype[index]=randomValidElement(range, index, genotype[index]);
+		}
+	}
+
+	/**
+	 * Return a randomly chosen element of the mutable subset lying in the range
+	 * or the old value if the randomly chosen value 
+	 * @param range
+	 * @param index
+	 * @param oldVal
+	 * @return
+	 */
+	private int randomValidElement(int[][] range, int index, int oldVal) {
+		int v = mutableSet[RNG.randomInt(mutableSet.length)];
+		if (v>=range[index][0] && (v<=range[index][1])) return v;
+		else {
+			EVAERROR.errorMsgOnce("Warning, mutation subset violates range definition!");
+			return oldVal;
+		}
+	}
+
+	/**
+	 * Return true if the given value is member of the mutable subset, otherwise false.
+	 * @param v
+	 * @return
+	 */
+	private boolean isMutable(int v) {
+		for (int i=0; i<mutableSet.length; i++) {
+			if (mutableSet[i]==v) return true;
+		}
+		return false;
+	}
+
+	public static String globalInfo() {
+		return "A mutation operator which switches positions within a given subset only. A random " +
+				"position is chosen but mutated only if its allele is contained" +
+				" in the mutable set. The new allele is chosen from this set as well." +
+				" In case the random positions do not contain a mutable allele, the switching is skipped. " +
+				"This means that fewer switches may occur than expected from the minimal bound.";
+	}
+	
+	public int[] getMutableSet() {
+		return mutableSet;
+	}
+	public void setMutableSet(int[] mutationSubset) {
+		this.mutableSet = mutationSubset;
+	}
+	public String mutableSetTipText() {
+		return "A subset of integers among which mutations may occur.";
+	}
+
+	public int getMinNumMutations() {
+		return minNumMutations;
+	}
+	public void setMinNumMutations(int minNumMutations) {
+		this.minNumMutations = minNumMutations;
+	}
+	public String minNumMutationsTipText() {
+		return "A lower bound for the number of positions changed per mutation event";
+	}
+	
+	public int getMaxNumMutations() {
+		return maxNumMutations;
+	}
+	public void setMaxNumMutations(int maxNumMutations) {
+		this.maxNumMutations = maxNumMutations;
+	}
+	public String maxNumMutationsTipText() {
+		return "An upper bound for the number of positions changed per mutation event";
+	}
+
+	public boolean isEnforceMutablePositions() {
+		return enforceMutablePositions;
+	}
+	public void setEnforceMutablePositions(boolean enforceMutablePositions) {
+		this.enforceMutablePositions = enforceMutablePositions;
+	}
+	public String enforceMutablePositionsTipText() {
+		return "If true, the probability to hit a mutable position in a mutation event is increased by trying multiple times.";
+	}
+}