Changeset 14251 for branches/symbreg-factors-2650/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Importer/InfixExpressionParser.cs

Timestamp:

08/10/16 20:10:25 (8 years ago)

Author:

gkronber

Message:

#2650:

• extended non-linear regression to work with factors
• fixed bugs in constants optimizer and tree interpreter
• improved simplification of factor variables
• added support for factors to ERC view
• added support for factors to solution comparison view
• activated view for all factors

File:

• branches/symbreg-factors-2650/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Importer/InfixExpressionParser.cs (modified) (7 diffs)

branches/symbreg-factors-2650/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Importer/InfixExpressionParser.cs

@@ -32 +32 @@
   /// Parses mathematical expressions in infix form. E.g. x1 * (3.0 * x2 + x3)
   /// Identifier format (functions or variables): '_' | letter { '_' | letter | digit }
-  /// Variables names can be set under quotes "" or '' because variable names might contain spaces. 
+  /// Variables names and variable values can be set under quotes "" or '' because variable names might contain spaces. 
+  ///   Variable = ident | " ident " | ' ident ' 
   /// It is also possible to use functions e.g. log("x1") or real-valued constants e.g. 3.1415 . 
   /// Variable names are case sensitive. Function names are not case sensitive.
+  /// 
+  /// 
+  /// S       = Expr EOF
+  /// Expr    = ['-' | '+'] Term { '+' Term | '-' Term }
+  /// Term    = Fact { '*' Fact | '/' Fact }
+  /// Fact    = '(' Expr ')' | funcId '(' Expr ')' | VarExpr | number
+  /// VarExpr = varId [ '=' varVal]
+  /// varId   =  ident | ' ident ' | " ident "
+  /// varVal  =  ident | ' ident ' | " ident "
+  /// ident   =  '_' | letter { '_' | letter | digit }
   /// </summary>
   public sealed class InfixExpressionParser {
-    private enum TokenType { Operator, Identifier, Number, LeftPar, RightPar, End, NA };
+    private enum TokenType { Operator, Identifier, Number, LeftPar, RightPar, Eq, End, NA };
     private class Token {
       internal double doubleVal;
@@ -64 +75 @@
     private Constant constant = new Constant();
     private Variable variable = new Variable();
+    private BinaryFactorVariable binaryFactorVar = new BinaryFactorVariable();
 
     private ProgramRootSymbol programRootSymbol = new ProgramRootSymbol();
@@ -143 +155 @@
           pos++;
           while (pos < str.Length && !char.IsWhiteSpace(str[pos])
-            && (str[pos] != '+' || str[pos-1] == 'e' || str[pos-1] == 'E')     // continue reading exponents
+            && (str[pos] != '+' || str[pos - 1] == 'e' || str[pos - 1] == 'E')     // continue reading exponents
             && (str[pos] != '-' || str[pos - 1] == 'e' || str[pos - 1] == 'E')
-            && str[pos] != '*'           
+            && str[pos] != '*'
             && str[pos] != '/'
             && str[pos] != ')') {
@@ -211 +223 @@
           pos++;
           yield return new Token { TokenType = TokenType.RightPar, strVal = ")" };
-        }
-      }
-    }
-
-    // S = Expr EOF
-    // Expr = ['-' | '+'] Term { '+' Term | '-' Term }
-    // Term = Fact { '*' Fact | '/' Fact }
-    // Fact = '(' Expr ')' | funcId '(' Expr ')' | varId | number
+        } else if (str[pos] == '=') {
+          pos++;
+          yield return new Token { TokenType = TokenType.Eq, strVal = "=" };
+        }
+      }
+    }
+
     private ISymbolicExpressionTreeNode ParseS(Queue<Token> tokens) {
       var expr = ParseExpr(tokens);
@@ -326 +337 @@
     }
 
-    // Fact = '(' Expr ')' | funcId '(' Expr ')' | varId | number
+    // Fact = '(' Expr ')' | funcId '(' Expr ')' | varId [ = valId ] | number
     private ISymbolicExpressionTreeNode ParseFact(Queue<Token> tokens) {
       var next = tokens.Peek();
@@ -355 +366 @@
         } else {
           // variable
-          var varNode = (VariableTreeNode)variable.CreateTreeNode();
-          varNode.Weight = 1.0;
-          varNode.VariableName = idTok.strVal;
-          return varNode;
+          if (tokens.Peek().TokenType == TokenType.Eq) {
+            // binary factor
+            tokens.Dequeue(); // skip Eq
+            var valTok = tokens.Dequeue();
+            if (valTok.TokenType != TokenType.Identifier) throw new ArgumentException("expected identifier");
+            var binFactorNode = (BinaryFactorVariableTreeNode)binaryFactorVar.CreateTreeNode();
+            binFactorNode.Weight = 1.0;
+            binFactorNode.VariableName = idTok.strVal;
+            binFactorNode.VariableValue = valTok.strVal;
+            return binFactorNode;
+          } else {
+            // variable
+            var varNode = (VariableTreeNode)variable.CreateTreeNode();
+            varNode.Weight = 1.0;
+            varNode.VariableName = idTok.strVal;
+            return varNode;
+          }
         }
       } else if (next.TokenType == TokenType.Number) {
@@ -369 +393 @@
       }
     }
+
   }
 }