Changeset 6489

Timestamp:

06/27/11 23:56:35 (14 years ago)

Author:

cneumuel

Message:

#1215

• fixed issue with multiple problems (by introducing valuesReadOnly to IOptimizable)
• fixed error message when removing last problem instance
• made quality measure name configurable

Location:

branches/HeuristicLab.MetaOptimization

Files:

• HeuristicLab.MetaOptimization.Test/Program.cs (modified) (8 diffs)
• HeuristicLab.Problems.MetaOptimization.Views/3.3/HeuristicLab.Problems.MetaOptimization.Views-3.3.csproj (modified) (1 diff)
• HeuristicLab.Problems.MetaOptimization.Views/3.3/MessageItem.cs (added)
• HeuristicLab.Problems.MetaOptimization.Views/3.3/OptimizableView.cs (modified) (1 diff)
• HeuristicLab.Problems.MetaOptimization/3.3/Analyzers/PMOBestSolutionHistoryAnalyzer.cs (modified) (1 diff)
• HeuristicLab.Problems.MetaOptimization/3.3/Analyzers/SolutionCacheAnalyzer.cs (modified) (1 diff)
• HeuristicLab.Problems.MetaOptimization/3.3/Encoding/ParameterCombinationsEnumerator.cs (modified) (1 diff)
• HeuristicLab.Problems.MetaOptimization/3.3/Encoding/ParameterConfigurationTree.cs (modified) (2 diffs)
• HeuristicLab.Problems.MetaOptimization/3.3/Encoding/ParameterConfigurations/ParameterConfiguration.cs (modified) (3 diffs)
• HeuristicLab.Problems.MetaOptimization/3.3/Encoding/ValueConfigurations/ParameterizedValueConfiguration.cs (modified) (1 diff)
• HeuristicLab.Problems.MetaOptimization/3.3/Encoding/ValueConfigurations/ValueConfiguration.cs (modified) (2 diffs)
• HeuristicLab.Problems.MetaOptimization/3.3/Evaluators/AlgorithmRunsAnalyzer.cs (modified) (6 diffs)
• HeuristicLab.Problems.MetaOptimization/3.3/Interfaces/IOptimizable.cs (modified) (1 diff)
• HeuristicLab.Problems.MetaOptimization/3.3/MetaOptimizationProblem.cs (modified) (10 diffs)

branches/HeuristicLab.MetaOptimization/HeuristicLab.MetaOptimization.Test/Program.cs

@@ -24 +24 @@
 using HeuristicLab.Problems.MetaOptimization;
 using HeuristicLab.Problems.TestFunctions;
-using HeuristicLab.Problems.TravelingSalesman;
 using HeuristicLab.Random;
 using HeuristicLab.Selection;
@@ -49 +48 @@
     //private static double mutationProbability = 0.10;
 
-    private static int metaAlgorithmPopulationSize = 30;
+    private static int metaAlgorithmPopulationSize = 3;
     private static int metaAlgorithmMaxGenerations = 10;
     private static double metaAlgorithmMutationProbability = 0.10;
-    private static int metaProblemRepetitions = 3;
-    private static int baseAlgorithmMaxGenerations = 20;
-    private static int baseAlgorithmPopulationSize = 100;
+    private static int metaProblemRepetitions = 2;
+    private static int baseAlgorithmMaxGenerations = 1;
+    private static int baseAlgorithmPopulationSize = 5;
 
     public override void Run() {
@@ -87 +86 @@
 
       //TestSymbolicDataAnalysisGrammar(); return;
-      TestObjectGraphObjectsTraversal(); return;
+      //TestObjectGraphObjectsTraversal(); return;
       //TestParameterizedItem(); return;
 
@@ -93 +92 @@
       //var algorithmVc = metaOptimizationProblem.ParameterConfigurationTree;
 
-      var metaOptimizationProblem = new MetaOptimizationProblem();
-      var algorithmVc = SetupGAAlgorithm(typeof(GeneticAlgorithm), metaOptimizationProblem);
+      //var metaOptimizationProblem = new MetaOptimizationProblem();
+      //var algorithmVc = SetupGAAlgorithm(typeof(GeneticAlgorithm), metaOptimizationProblem);
+
+      // import classification 4 problems
+      var metaOptimizationProblem = ((MetaOptimizationProblem)ContentManager.Load("MetaOpt GA,OSGA,Classification (melanoma,respiratory,wisconsin,prostata),MSE-Evaluator_test.hl"));
+      metaOptimizationProblem.QualityMeasureNameParameter.Value.Value = "Best training solution.Mean squared error (test)";
 
       metaOptimizationProblem.Repetitions = new IntValue(metaProblemRepetitions);
-      //GeneticAlgorithm metaLevelAlgorithm = GetSequentialMetaGA(metaOptimizationProblem);
-      GeneticAlgorithm metaLevelAlgorithm = GetParallelMetaGA(metaOptimizationProblem);
+      GeneticAlgorithm metaLevelAlgorithm = GetSequentialMetaGA(metaOptimizationProblem);
+      //GeneticAlgorithm metaLevelAlgorithm = GetParallelMetaGA(metaOptimizationProblem);
       //GeneticAlgorithm metaLevelAlgorithm = GetHiveParallelMetaGA(metaOptimizationProblem);
       //EvolutionStrategy metaLevelAlgorithm = GetMetaES(metaOptimizationProblem);
@@ -105 +108 @@
       //TestConfiguration(algorithmVc, typeof(GeneticAlgorithm), metaOptimizationProblem.Problems.First());
 
-      Console.WriteLine("Press enter to start"); Console.ReadLine();
+      //Console.WriteLine("Press enter to start"); Console.ReadLine();
       TestOptimization(metaLevelAlgorithm);
 
@@ -809 +812 @@
 
       // tsp
-      metaOptimizationProblem.ProblemType.Value = typeof(TravelingSalesmanProblem);
+      //metaOptimizationProblem.ProblemType.Value = typeof(TravelingSalesmanProblem);
 
       ParameterConfigurationTree algorithmVc = metaOptimizationProblem.ParameterConfigurationTree;
@@ -815 +818 @@
       ((IntValue)algorithmVc.AlgorithmConfiguration.ParameterConfigurations.Single(x => x.Name == "PopulationSize").ActualValue.Value).Value = baseAlgorithmPopulationSize;
 
-      ConfigurePopulationSize(algorithmVc, 10, 100, 1);
-      ConfigureMutationRate(algorithmVc, 0.0, 1.0, 0.01);
-      ConfigureMutationOperator(algorithmVc);
-      ConfigureElites(algorithmVc, 0, 10, 1);
-      ConfigureSelectionOperator(algorithmVc, true);
+      //ConfigurePopulationSize(algorithmVc, 10, 100, 1);
+      //ConfigureMutationRate(algorithmVc, 0.0, 1.0, 0.01);
+      //ConfigureMutationOperator(algorithmVc);
+      //ConfigureElites(algorithmVc, 0, 5, 1);
+      //ConfigureSelectionOperator(algorithmVc, true);
 
       //ConfigureSymbolicExpressionGrammar(algorithmVc);
@@ -1052 +1055 @@
 
         StringBuilder sb1 = new StringBuilder();
-        sb1.AppendFormat("Meta.PopulationSize: {0}\n", metaAlgorithmPopulationSize);
-        sb1.AppendFormat("Meta.MaxGenerations: {0}\n", metaAlgorithmMaxGenerations);
-        sb1.AppendFormat("Meta.Repetitions   : {0}\n", metaProblemRepetitions);
-        sb1.AppendFormat("Meta.MutProb       : {0}\n", ((GeneticAlgorithm)metaLevelAlgorithm).MutationProbability.Value);
-        sb1.AppendFormat("Meta.Seed          : {0}\n", ((GeneticAlgorithm)metaLevelAlgorithm).Seed.Value);
-        sb1.AppendFormat("Base.MaxGenerations: {0}\n", baseAlgorithmMaxGenerations);
+        sb1.AppendFormat("Meta-PopulationSize: {0}\n", metaAlgorithmPopulationSize);
+        sb1.AppendFormat("Meta-MaxGenerations: {0}\n", metaAlgorithmMaxGenerations);
+        sb1.AppendFormat("Meta-Repetitions   : {0}\n", metaProblemRepetitions);
+        sb1.AppendFormat("Meta-MutProb       : {0}\n", ((GeneticAlgorithm)metaLevelAlgorithm).MutationProbability.Value);
+        sb1.AppendFormat("Meta-Seed          : {0}\n", ((GeneticAlgorithm)metaLevelAlgorithm).Seed.Value);
+        sb1.AppendFormat("Base-MaxGenerations: {0}\n", baseAlgorithmMaxGenerations);
 
         sb1.AppendLine("Problems:");

branches/HeuristicLab.MetaOptimization/HeuristicLab.Problems.MetaOptimization.Views/3.3/HeuristicLab.Problems.MetaOptimization.Views-3.3.csproj

@@ -153 +153 @@
       <DependentUpon>ItemDictionaryView.cs</DependentUpon>
     </Compile>
+    <Compile Include="MessageItem.cs" />
     <Compile Include="MetaOptimizationProblemView.cs">
       <SubType>UserControl</SubType>

branches/HeuristicLab.MetaOptimization/HeuristicLab.Problems.MetaOptimization.Views/3.3/OptimizableView.cs

@@ -79 +79 @@
         } else {
           this.viewHost.ViewsLabelVisible = false;
-          this.viewHost.Content = Content.ActualValue;
+          if (Content.ValuesReadOnly) {
+            this.viewHost.Content = new MessageItem("Cannot modify value directly. Please modify the value in the list of problems.");
+          } else {
+            this.viewHost.Content = Content.ActualValue;
+          }
         }
       }

branches/HeuristicLab.MetaOptimization/HeuristicLab.Problems.MetaOptimization/3.3/Analyzers/PMOBestSolutionHistoryAnalyzer.cs

@@ -75 +75 @@
         bestSolutionHistory = results[key].Value as RunCollection;
       }
-      if (bestSolutionHistory.Count == 0 || best.ParameterInfoString != ((StringValue)bestSolutionHistory.Last().Results["Meta.ParameterInfoString"]).Value) {
+      if (bestSolutionHistory.Count == 0 || best.ParameterInfoString != ((StringValue)bestSolutionHistory.Last().Results["Meta-ParameterInfoString"]).Value) {
         IRun run = best.ToRun(string.Format("{0}: {1}", currentGeneration, best.ParameterInfoString), false);
-        run.Results.Add("Meta.Generation", new IntValue(currentGeneration));
-        run.Results.Add("Meta.ParameterInfoString", new StringValue(best.ParameterInfoString));
+        run.Results.Add("Meta-Generation", new IntValue(currentGeneration));
+        run.Results.Add("Meta-ParameterInfoString", new StringValue(best.ParameterInfoString));
         bestSolutionHistory.Add(run);
       }

branches/HeuristicLab.MetaOptimization/HeuristicLab.Problems.MetaOptimization/3.3/Analyzers/SolutionCacheAnalyzer.cs

@@ -74 +74 @@
           var runCollection = allRuns.Single(x => x.Key.Value == key).Value;
           foreach (var run in solution.Runs) {
-            if (!((BoolValue)run.Results["Meta.FromCache"]).Value || first) {
-              run.Results["Meta.FromCache"] = new BoolValue(true);
+            if (!((BoolValue)run.Results["Meta-FromCache"]).Value || first) {
+              run.Results["Meta-FromCache"] = new BoolValue(true);
               runCollection.Add(run);
             }

branches/HeuristicLab.MetaOptimization/HeuristicLab.Problems.MetaOptimization/3.3/Encoding/ParameterCombinationsEnumerator.cs

@@ -22 +22 @@
       get {
         if (!initialized)
-          throw new SystemException("Enumeration not started. Call MoveNext!");
+          throw new InvalidOperationException("Enumeration not started. Call MoveNext!");
         return Current;
       }

branches/HeuristicLab.MetaOptimization/HeuristicLab.Problems.MetaOptimization/3.3/Encoding/ParameterConfigurationTree.cs

@@ -161 +161 @@
       this.parameterConfigurations.Add(new SingleValuedParameterConfiguration("Algorithm", algproblemitem.AlgorithmParameter));
       this.parameterConfigurations.Add(new SingleValuedParameterConfiguration("Problem", algproblemitem.ProblemParameter));
+
+      // problems can be modified in the list of problem instances, so the parameters which are not Optimize=true, 
+      // must not be modifiable in the parameter configuration tree. otherwise the parameter values would be ambiguous
+      ProblemConfiguration.ValuesReadOnly = true;
     }
     public ParameterConfigurationTree() { }
@@ -190 +194 @@
     [StorableHook(HookType.AfterDeserialization)]
     private void AfterDeserialization() {
+      if(ProblemConfiguration != null) ProblemConfiguration.ValuesReadOnly = true;
     }
     #endregion

branches/HeuristicLab.MetaOptimization/HeuristicLab.Problems.MetaOptimization/3.3/Encoding/ParameterConfigurations/ParameterConfiguration.cs

@@ -146 +146 @@
     }
 
+    [Storable]
+    protected bool valuesReadOnly = false;
+    public virtual bool ValuesReadOnly {
+      get { return valuesReadOnly; }
+      set {
+        if (value != this.valuesReadOnly) {
+          this.valuesReadOnly = value;
+          foreach (var vc in this.valueConfigurations) {
+            vc.ValuesReadOnly = value;
+          }
+        }
+      }
+    }
 
     #region Constructors and Cloning
@@ -220 +233 @@
       this.discoverValidValues = original.discoverValidValues;
       this.AutoPopulateValueConfigurations = original.AutoPopulateValueConfigurations;
+      this.valuesReadOnly = original.valuesReadOnly;
     }
 
@@ -485 +499 @@
 
     public void Parameterize(IValueParameter parameter) {
+      if (!Optimize && ValuesReadOnly)
+        return;
+
       if (Optimize) {
         if (this.ActualValue.Value is IParameterizedItem) {

branches/HeuristicLab.MetaOptimization/HeuristicLab.Problems.MetaOptimization/3.3/Encoding/ValueConfigurations/ParameterizedValueConfiguration.cs

@@ -46 +46 @@
       get { return discoverValidValues; }
       set { discoverValidValues = value; }
+    }
+
+    public override bool ValuesReadOnly {
+      set {
+        if (value != this.valuesReadOnly) {
+          this.valuesReadOnly = value;
+          foreach (var pc in this.parameterConfigurations) {
+            pc.ValuesReadOnly = value;
+          }
+        }
+      }
     }
 

branches/HeuristicLab.MetaOptimization/HeuristicLab.Problems.MetaOptimization/3.3/Encoding/ValueConfigurations/ValueConfiguration.cs

@@ -73 +73 @@
     }
 
+    [Storable]
+    protected bool valuesReadOnly = false;
+    public virtual bool ValuesReadOnly {
+      get { return valuesReadOnly; }
+      set {
+        if (value != this.valuesReadOnly) {
+          this.valuesReadOnly = value;
+        }
+      }
+    }
+
     #region Constructors and Cloning
     public ValueConfiguration(IItem value, Type valueDataType) {
@@ -88 +99 @@
       this.optimize = original.optimize;
       this.number = original.number;
+      this.valuesReadOnly = original.valuesReadOnly;
       RegisterActualValueEvents();
     }

branches/HeuristicLab.MetaOptimization/HeuristicLab.Problems.MetaOptimization/3.3/Evaluators/AlgorithmRunsAnalyzer.cs

@@ -69 +69 @@
     public IScope CurrentScope {
       get { return CurrentScopeParameter.ActualValue; }
+    }
+    public LookupParameter<StringValue> QualityMeasureNameParameter {
+      get { return (LookupParameter<StringValue>)Parameters[MetaOptimizationProblem.QualityMeasureNameName]; }
     }
     #endregion
@@ -93 +96 @@
       Parameters.Add(new LookupParameter<DoubleValue>(MetaOptimizationProblem.StandardDeviationWeightParameterName));
       Parameters.Add(new LookupParameter<DoubleValue>(MetaOptimizationProblem.EvaluatedSolutionsWeightParameterName));
+      Parameters.Add(new LookupParameter<StringValue>(MetaOptimizationProblem.QualityMeasureNameName));
       Parameters.Add(new ScopeParameter("CurrentScope", "The current scope whose sub-scopes represent the parents."));
     }
@@ -104 +108 @@
     private void AfterDeserialization() {
       if (!Parameters.ContainsKey("CurrentScope")) Parameters.Add(new ScopeParameter("CurrentScope", "The current scope whose sub-scopes represent the parents.")); // backwards compatibility
+      if (!Parameters.ContainsKey(MetaOptimizationProblem.QualityMeasureNameName)) Parameters.Add(new LookupParameter<StringValue>(MetaOptimizationProblem.QualityMeasureNameName)); // backwards compatibility
     }
 
@@ -118 +123 @@
       double standardDeviationWeight = StandardDeviationWeightParameter.ActualValue.Value;
       double evaluatedSolutionsWeight = EvaluatedSolutionsWeightParameter.ActualValue.Value;
-      var resultNames = new List<string> { "BestQuality", "Execution Time", "EvaluatedSolutions" };
+      string qualityMeasureName = QualityMeasureNameParameter.ActualValue.Value;
+      var resultNames = new List<string> { qualityMeasureName, "Execution Time", "EvaluatedSolutions" };
       int currentGeneration = GenerationsParameter.ActualValue != null ? GenerationsParameter.ActualValue.Value : 0;
       double[] referenceQualityAverages;
@@ -146 +152 @@
           MetaOptimizationUtil.ClearResults(run, resultNames);
           MetaOptimizationUtil.ClearParameters(run, parameterNames);
-          run.Results.Add("Meta.FromCache", new BoolValue(false));
-          run.Results.Add("Meta.Generation", new IntValue(currentGeneration));
-          run.Results.Add("Meta.ProblemIndex", new IntValue(problemIndex));
+          run.Results.Add("Meta-FromCache", new BoolValue(false));
+          run.Results.Add("Meta-Generation", new IntValue(currentGeneration));
+          run.Results.Add("Meta-ProblemIndex", new IntValue(problemIndex));
           run.Name = string.Format("{0} Problem {1} Run {2}", parameterConfiguration.ParameterInfoString, problemIndex, repetitionIndex);
-          qualities[problemIndex][repetitionIndex] = (((DoubleValue)run.Results["BestQuality"]).Value);
+          
+          qualities[problemIndex][repetitionIndex] = GetResultValue<DoubleValue>(run.Results, qualityMeasureName).Value; 
           executionTimes[problemIndex][repetitionIndex] = (((TimeSpanValue)run.Results["Execution Time"]).Value);
           evaluatedSolutions[problemIndex][repetitionIndex] = (((IntValue)run.Results["EvaluatedSolutions"]).Value);
@@ -203 +210 @@
       
       return base.Apply();
+    }
+
+    private T1 GetResultValue<T1>(IDictionary<string, IItem> results, string resultName) {
+      return (T1)results[resultName];
+
+      //string separator = ".";
+      //string[] tokens = resultName.Split(separator.ToCharArray());
+
+      //IDictionary<string, IItem> currentResults = results;
+      //IItem currentResult = null;
+      //for (int i = 0; i < tokens.Length; i++) {
+      //  if(currentResults == null)
+      //    throw new KeyNotFoundException("Result value " + resultName + " was not found");
+      //  if (currentResults.ContainsKey(tokens[i])) {
+      //    currentResult = currentResults[tokens[i]];
+      //    currentResults = currentResult as IDictionary<string, IItem>;
+      //  } else {
+      //    throw new KeyNotFoundException("Result value " + resultName + " was not found");
+      //  }
+      //}
+      //return (T1)currentResult;
     }
 

branches/HeuristicLab.MetaOptimization/HeuristicLab.Problems.MetaOptimization/3.3/Interfaces/IOptimizable.cs

@@ -26 +26 @@
     event EventHandler IsOptimizableChanged;
     event EventHandler OptimizeChanged;
+
+    /// <summary>
+    /// indicates if the actualvalues are modifiable
+    /// </summary>
+    bool ValuesReadOnly { get; set; }
   }
 }

branches/HeuristicLab.MetaOptimization/HeuristicLab.Problems.MetaOptimization/3.3/MetaOptimizationProblem.cs

@@ -40 +40 @@
   public sealed class MetaOptimizationProblem : SingleObjectiveHeuristicOptimizationProblem<IParameterConfigurationEvaluator, IParameterConfigurationCreator>, IStorableContent {
     public string Filename { get; set; }
-    
+
     public const string AlgorithmTypeParameterName = "AlgorithmType";
     public const string ProblemTypeParameterName = "ProblemType";
@@ -46 +46 @@
     public const string ParameterConfigurationTreeParameterName = "ParameterConfiguration";
     public const string RepetitionsParameterName = "Repetitions";
+    public const string QualityMeasureNameName = "QualityMeasureName";
 
     public const string IntValueManipulatorParameterName = "IntValueManipulator";
@@ -67 +68 @@
     }
     public IValueParameter<ParameterConfigurationTree> ParameterConfigurationTreeParameter {
-      get { return (ValueParameter<ParameterConfigurationTree>)Parameters[ParameterConfigurationTreeParameterName]; }
+      get { return (OptionalValueParameter<ParameterConfigurationTree>)Parameters[ParameterConfigurationTreeParameterName]; }
     }
     public IValueParameter<IntValue> RepetitionsParameter {
@@ -79 +80 @@
     public IValueParameter<IDoubleValueManipulator> DoubleValueManipulatorParameter {
       get { return (ValueParameter<IDoubleValueManipulator>)Parameters[DoubleValueManipulatorParameterName]; }
+    }
+    public IValueParameter<StringValue> QualityMeasureNameParameter {
+      get { return (ValueParameter<StringValue>)Parameters[QualityMeasureNameName]; }
     }
     #endregion
@@ -131 +135 @@
       Parameters.Add(new ValueParameter<ConstrainedTypeValue<IProblem>>(ProblemTypeParameterName, "The problem type.", new ConstrainedTypeValue<IProblem>()));
       Parameters.Add(new ValueParameter<ConstrainedItemList<IProblem>>(ProblemsParameterName, "The problems that should be evaluated.", new ConstrainedItemList<IProblem>()));
-      Parameters.Add(new ValueParameter<ParameterConfigurationTree>(ParameterConfigurationTreeParameterName, "Tree of algorithm parameters that should be optimized."));
+      Parameters.Add(new OptionalValueParameter<ParameterConfigurationTree>(ParameterConfigurationTreeParameterName, "Tree of algorithm parameters that should be optimized.")); // needs to be optional, when last problem is removed from list, it must be set null
       Parameters.Add(new ValueParameter<IntValue>(RepetitionsParameterName, "The number of evaluations for each problem.", new IntValue(3)));
+      Parameters.Add(new ValueParameter<StringValue>(QualityMeasureNameName, "The name of the quality result of the base-level algorithm. Subresults can be accessed by dot separator.", new StringValue("BestQuality")));
 
       var validIntManipulators = new ItemSet<IIntValueManipulator>(ApplicationManager.Manager.GetInstances<IIntValueManipulator>());
@@ -174 +179 @@
     [StorableHook(HookType.AfterDeserialization)]
     private void AfterDeserializationHook() {
+      if(!Parameters.ContainsKey(QualityMeasureNameName)) Parameters.Add(new ValueParameter<StringValue>(QualityMeasureNameName, "The name of the quality result of the base-level algorithm. Subresults can be accessed by dot separator.", new StringValue("BestQuality"))); // backwards compatibility
       RegisterParameterEvents();
     }
@@ -211 +217 @@
       if (RunsAnalyzer != null) {
         RunsAnalyzer.ParameterConfigurationParameter.ActualName = ((RandomParameterConfigurationCreator)SolutionCreator).ParameterConfigurationParameter.ActualName;
-      } 
+      }
       if (PMOPopulationDiversityAnalyzer != null) {
         PMOPopulationDiversityAnalyzer.SolutionParameter.ActualName = ((RandomParameterConfigurationCreator)SolutionCreator).ParameterConfigurationParameter.ActualName;
@@ -260 +266 @@
       IAlgorithm instance = (IAlgorithm)Activator.CreateInstance(AlgorithmType.Value);
       this.ProblemType.ValidTypes = ApplicationManager.Manager.GetTypes(instance.ProblemType, true).ToList();
-      this.ProblemType.Value = this.ProblemType.ValidTypes.SingleOrDefault(t => t == typeof(SingleObjectiveTestFunctionProblem)) ?? this.ProblemType.ValidTypes.Where(t => t != typeof(MetaOptimizationProblem)).FirstOrDefault();
-      // ProblemType_ValueChanged will add one problem and create ParameterConfigurationTree
+      var newProblemType = this.ProblemType.ValidTypes.SingleOrDefault(t => t == typeof(SingleObjectiveTestFunctionProblem)) ?? this.ProblemType.ValidTypes.Where(t => t != typeof(MetaOptimizationProblem)).FirstOrDefault();
+      if (this.ProblemType.Value != newProblemType)
+        this.ProblemType.Value = newProblemType; // ProblemType_ValueChanged will add one problem and create ParameterConfigurationTree
+      else
+        ProblemType_ValueChanged(this, EventArgs.Empty); // call explicitly
     }
 
@@ -274 +283 @@
     }
 
-    private void Problems_ItemsAdded(object sender, Collections.CollectionItemsChangedEventArgs<IndexedItem<IProblem>> e) {
+    private void Problems_ItemsAdded(object sender, CollectionItemsChangedEventArgs<IndexedItem<IProblem>> e) {
       // the first problem in the list is always the instance for the algorithm - this way some basic wiring between problem and algorithm can be sustained
       if (e.Items.Single().Index == 0) {
@@ -287 +296 @@
     }
 
-    private void Problems_ItemsRemoved(object sender, Collections.CollectionItemsChangedEventArgs<IndexedItem<IProblem>> e) {
+    private void Problems_ItemsRemoved(object sender, CollectionItemsChangedEventArgs<IndexedItem<IProblem>> e) {
       if (e.Items.Single().Index == 0) {
         ParameterConfigurationTreeParameter.ActualValue = null;