Changeset 5915

Timestamp:

03/31/11 18:41:41 (14 years ago)

Author:

gkronber

Message:

#1418 Fixed bug in symbolic data analysis expression tree simplifier and added test cases.

Location:

trunk/sources/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4

Files:

• SymbolicDataAnalysisExpressionTreeSimplifier.cs (modified) (1 diff)
• Tests/SymbolicDataAnalysisExpressionTreeSimplifierTest.cs (modified) (1 diff)

trunk/sources/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/SymbolicDataAnalysisExpressionTreeSimplifier.cs

@@ -905 +905 @@
       } else if (IsMultiplication(x) || IsDivision(x)) {
         // x0 * x1 * .. * xn * -1 => x0 * x1 * .. * -xn
-        x.RemoveSubtree(x.Subtrees.Count() - 1);
-        x.AddSubtree(Negate(x.Subtrees.Last())); // last is maybe a constant, prefer to negate the constant
+        var lastSubTree = x.Subtrees.Last();
+        x.RemoveSubtree(x.SubtreesCount - 1);
+        x.AddSubtree(Negate(lastSubTree)); // last is maybe a constant, prefer to negate the constant
       } else {
         // any other function

trunk/sources/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Tests/SymbolicDataAnalysisExpressionTreeSimplifierTest.cs

@@ -162 +162 @@
         Assert.AreEqual(formatter.Format(expectedTree), formatter.Format(actualTree));
       }
+      {
+        // exp transformation
+        var actualTree = simplifier.Simplify(importer.Import("(exp (- (variable 2.0 a) (* (variable 3.0 b) (variable 4.0 c))))"));
+        var expectedTree = importer.Import("(* (exp (variable 2.0 a)) (exp (* (variable 1.0 b) (variable 1.0 c) -12.0)))");
+        Assert.AreEqual(formatter.Format(expectedTree), formatter.Format(actualTree));
+      }
+      {
+        // exp transformation
+        var actualTree = simplifier.Simplify(importer.Import("(exp (- (variable 2.0 a) (* (variable 3.0 b) (cos (variable 4.0 c)))))"));
+        var expectedTree = importer.Import("(* (exp (variable 2.0 a)) (exp (* (variable 1.0 b) (cos (variable 4.0 c)) -3.0)))");
+        Assert.AreEqual(formatter.Format(expectedTree), formatter.Format(actualTree));
+      }
       #endregion
       #region power rules