Changeset 17663

Timestamp:

07/12/20 11:16:10 (4 years ago)

Author:

dleko

Message:

#2825 Initialize population size with the correct number (according to NSGA-III paper).

Location:

branches/2825-NSGA3/HeuristicLab.Algorithms.NSGA3/3.3

Files:

• NSGA3.cs (modified) (3 diffs)
• ReferencePoint.cs (modified) (4 diffs)

branches/2825-NSGA3/HeuristicLab.Algorithms.NSGA3/3.3/NSGA3.cs

@@ -173 +173 @@
             Parameters.Add(new FixedValueParameter<IntValue>(SeedName, "The random seed used to initialize the new pseudo random number generator.", new IntValue(0)));
             Parameters.Add(new FixedValueParameter<BoolValue>(SetSeedRandomlyName, "True if the random seed should be set to a random value, otherwise false.", new BoolValue(true)));
-            Parameters.Add(new FixedValueParameter<IntValue>(PopulationSizeName, "The size of the population of Individuals.", new IntValue(200)));
+            Parameters.Add(new FixedValueParameter<IntValue>(PopulationSizeName, "The size of the population of Individuals.", new IntValue(ReferencePoint.GetNumberOfGeneratedReferencePoints(NumberOfObjectives))));
             Parameters.Add(new FixedValueParameter<PercentValue>(CrossoverProbabilityName, "The probability that the crossover operator is applied on two parents.", new PercentValue(0.9)));
             Parameters.Add(new FixedValueParameter<DoubleValue>(CrossoverContiguityName, "The contiguity value for the Simulated Binary Crossover that specifies how close a child should be to its parents (larger value means closer). The value must be greater than or equal than 0. Typical values are in the range [2;5]."));
@@ -209 +209 @@
             base.Initialize(cancellationToken);
 
-            InitFields();
             InitResults();
             InitReferencePoints();
+            InitFields();
             Analyze();
+        }
+
+        private void InitReferencePoints()
+        {
+            // Generate reference points and add them to results
+            ReferencePoints = ReferencePoint.GenerateReferencePoints(random, NumberOfObjectives);
+            ResultsGeneratedReferencePoints = Utility.ConvertToDoubleMatrix(ReferencePoints);
         }
 
@@ -242 +249 @@
             Results.Add(new Result(GeneratedReferencePointsResultName, "The initially generated reference points", new DoubleMatrix()));
             Results.Add(new Result(CurrentFrontResultName, "The Pareto Front", new DoubleMatrix()));
-        }
-
-        private void InitReferencePoints()
-        {
-            // Generate reference points and add them to results
-            ReferencePoints = ReferencePoint.GenerateReferencePoints(random, NumberOfObjectives);
-            ResultsGeneratedReferencePoints = Utility.ConvertToDoubleMatrix(ReferencePoints);
         }
 

branches/2825-NSGA3/HeuristicLab.Algorithms.NSGA3/3.3/ReferencePoint.cs

@@ -40 +40 @@
 
         /// <summary>
+        /// Returns the number of reference points that would be created when using <see
+        /// cref="GenerateReferencePoints(IRandom, int)" />.
+        /// </summary>
+        /// <param name="nDim"></param>
+        /// <returns></returns>
+        internal static int GetNumberOfGeneratedReferencePoints(int nDim)
+        {
+            int outerDiv;
+            int innerDiv;
+            switch (nDim)
+            {
+                case 3:
+                    outerDiv = 12;
+                    innerDiv = 0;
+                    break;
+
+                case 5:
+                    outerDiv = 6;
+                    innerDiv = 0;
+                    break;
+
+                case 8:
+                    outerDiv = 3;
+                    innerDiv = 2;
+                    break;
+
+                case 10:
+                    outerDiv = 3;
+                    innerDiv = 2;
+                    break;
+
+                case 15:
+                    outerDiv = 2;
+                    innerDiv = 1;
+                    break;
+
+                default:
+                    return -1;
+            }
+
+            return GetNumberOfGeneratedReferencePoints(nDim, outerDiv, innerDiv);
+        }
+
+        internal static int GetNumberOfGeneratedReferencePoints(int nDim, int outerDiv, int innerDiv = 0)
+        {
+            return Utility.NCR(nDim + outerDiv - 1, outerDiv) + (innerDiv == 0 ? 0 : Utility.NCR(nDim + innerDiv - 1, innerDiv));
+        }
+
+        /// <summary>
         /// Generate reference points that are evenly distributed over a hyperplane with dimensions
         /// <paramref name="nDim" /> - 1 with the sum of the values in all dimensions being equal to
@@ -45 +94 @@
         /// -&gt; The number of inner divisions and outer divisions are determined based on the
         /// values provided in the NSGA-III paper, chapter V: Results. If different dimensions are
-        /// given, null is returned.
+        /// given, a NotSupportedException is thrown.
         /// </summary>
         /// <param name="random">
@@ -78 +127 @@
 
                 default:
-                    referencePoints = null;
-                    break;
+                    throw new NotSupportedException("Only the reference points for 3, 5, 8, 10 or 15 dimensions can be created.");
             }
 
             return referencePoints;
-        }
-
-        internal static List<ReferencePoint> GenerateReferencePoints(IRandom random, int nDim, int outerDiv)
-        {
-            return GenerateReferencePoints(random, nDim, outerDiv, 0);
         }
 
@@ -108 +151 @@
         /// not have inner reference points
         /// </returns>
-        internal static List<ReferencePoint> GenerateReferencePoints(IRandom random, int nDim, int outerDiv, int innerDiv)
+        internal static List<ReferencePoint> GenerateReferencePoints(IRandom random, int nDim, int outerDiv, int innerDiv = 0)
         {
             if (nDim <= 0) throw new ArgumentException("nDim must be greater than 0");