Changeset 11846 for branches/HeuristicLab.Problems.GrammaticalOptimization/HeuristicLab.Problems.GrammaticalOptimization/Problems/SymbolicRegressionPoly10Problem.cs

Timestamp:

02/01/15 16:32:26 (9 years ago)

Author:

gkronber

Message:

#2283 implemented bridge to HL (solve grammatical optimization problem instances with StandardGP and OffspringSelectionGP)

File:

• branches/HeuristicLab.Problems.GrammaticalOptimization/HeuristicLab.Problems.GrammaticalOptimization/Problems/SymbolicRegressionPoly10Problem.cs (modified) (6 diffs)

branches/HeuristicLab.Problems.GrammaticalOptimization/HeuristicLab.Problems.GrammaticalOptimization/Problems/SymbolicRegressionPoly10Problem.cs

@@ -3 +3 @@
 using System.Collections.Generic;
 using System.Collections.Specialized;
+using System.Diagnostics;
 using System.Linq;
 using System.Net;
@@ -9 +10 @@
 using System.Text;
 using HeuristicLab.Common;
+using HeuristicLab.Encodings.SymbolicExpressionTreeEncoding;
 
 namespace HeuristicLab.Problems.GrammaticalOptimization {
-  public class SymbolicRegressionPoly10Problem : IProblem {
+  public class SymbolicRegressionPoly10Problem : ISymbolicExpressionTreeProblem {
     //    private const string grammarString = @"
     //    G(E):
@@ -22 +24 @@
     ";
 
+    // for tree-based GP in HL we need a different grammar for the same language
+    // E = expr, S = sum, P = product
+    private const string hlGrammarString = @"
+    G(E):
+    E -> S | P | a | b | c | d | e | f | g | h | i | j
+    S -> EE | EEE
+    P -> EE | EEE
+    ";
+    // mininmal tree for the optimal expr (40 nodes)
+    // E S
+    //     E S
+    //         E P 
+    //           E a E b
+    //         E P 
+    //           E c E d
+    //         E P 
+    //           E e E f
+    //     E S
+    //         E P 
+    //           E a E g E i
+    //         E P 
+    //           E c E f E j
+
+    private SymbolicExpressionGrammar symbExprGrammar;
+    public ISymbolicExpressionGrammar SymbolicExpressionGrammar {
+      get {
+        return symbExprGrammar;
+      }
+    }
 
     private readonly IGrammar grammar;
@@ -31 +62 @@
     public SymbolicRegressionPoly10Problem() {
       this.grammar = new Grammar(grammarString);
+      this.symbExprGrammar = new GenericSymbExprGrammar(new Grammar(hlGrammarString));
 
       this.N = 500;
@@ -71 +103 @@
       return HeuristicLab.Common.Extensions.RSq(y, Enumerable.Range(0, N).Select(i => interpreter.Interpret(sentence, x[i])).ToArray());
     }
-
 
 
@@ -130 +161 @@
     }
 
+    public string ConvertTreeToSentence(ISymbolicExpressionTree tree) {
+      var sb = new StringBuilder();
+
+      TreeToSentence(tree.Root.GetSubtree(0).GetSubtree(0), sb);
+
+      return sb.ToString();
+    }
+
+    private void TreeToSentence(ISymbolicExpressionTreeNode treeNode, StringBuilder sb) {
+      if (treeNode.SubtreeCount == 0) {
+        // terminal
+        sb.Append(treeNode.Symbol.Name);
+      } else {
+        string op = string.Empty;
+        switch (treeNode.Symbol.Name) {
+          case "S": op = "+"; break;
+          case "P": op = "*"; break;
+          default: {
+              Debug.Assert(treeNode.SubtreeCount == 1);
+              break;
+            }
+        }
+        // nonterminal
+        if (op == "+") sb.Append("(");
+        TreeToSentence(treeNode.Subtrees.First(), sb);
+        foreach (var subTree in treeNode.Subtrees.Skip(1)) {
+          sb.Append(op);
+          TreeToSentence(subTree, sb);
+        }
+        if (op == "+") sb.Append(")");
+      }
+    }
   }
 }