fix chromosome ranking based on dominated count in fast non-dominated…

… sort (based on issue #12)
onclave · Mar 22, 2021 · 3c1be75 · 3c1be75
1 parent 1cc9a28
commit 3c1be75
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Showing 4 changed files with 23 additions and 10 deletions.
diff --git a/pom.xml b/pom.xml
@@ -74,7 +74,7 @@
         <dependency>
             <groupId>org.jfree</groupId>
             <artifactId>jfreechart</artifactId>
-            <version>1.5.1</version>
+            <version>1.5.3</version>
         </dependency>
         <dependency>
             <groupId>org.jfree</groupId>

diff --git a/src/main/java/com/debacharya/nsgaii/NSGA2.java b/src/main/java/com/debacharya/nsgaii/NSGA2.java
@@ -219,14 +219,20 @@ public void fastNonDominatedSort(Population population) {
 		if(population.getLast().getDominatedCount() == 0)
 			population.getLast().setRank(1);
 
-		for(Chromosome chromosome : populace)
-			for(Chromosome dominatedChromosome : chromosome.getDominatedChromosomes()) {
-
-				dominatedChromosome.incrementDominatedCount(-1);
-
-				if(dominatedChromosome.getDominatedCount() == 0)
-					dominatedChromosome.setRank(chromosome.getRank() + 1);
-			}
+		while(Service.populaceHasUnsetRank(populace)) {
+			populace.forEach(chromosome -> {
+				if(chromosome.getRank() != -1)
+					chromosome.getDominatedChromosomes().forEach(dominatedChromosome -> {
+						if(dominatedChromosome.getDominatedCount() > 0) {
+
+							dominatedChromosome.incrementDominatedCount(-1);
+
+							if(dominatedChromosome.getDominatedCount() == 0)
+								dominatedChromosome.setRank(chromosome.getRank() + 1);
+						}
+					});
+			});
+		}
 	}
 
 	/**

diff --git a/src/main/java/com/debacharya/nsgaii/Service.java b/src/main/java/com/debacharya/nsgaii/Service.java
@@ -177,6 +177,13 @@ public static boolean isInGeneticCode(List<IntegerAllele> geneticCode, int value
 		return false;
 	}
 
+	public static boolean populaceHasUnsetRank(List<Chromosome> populace) {
+		for(Chromosome chromosome : populace)
+			if(chromosome.getRank() == -1)
+				return true;
+		return false;
+	}
+
 	/**
 	 * an implementation of min-max normalization
 	 *

diff --git a/src/main/java/com/debacharya/nsgaii/datastructure/Chromosome.java b/src/main/java/com/debacharya/nsgaii/datastructure/Chromosome.java
@@ -168,7 +168,7 @@ public Chromosome getCopy() {
 
 	public void reset() {
 		this.dominatedCount = 0;
-		this.rank = Integer.MAX_VALUE;
+		this.rank = -1;
 		this.dominatedChromosomes = new ArrayList<>();
 	}