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source: branches/2925_AutoDiffForDynamicalModels/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Formatters/InfixExpressionFormatter.cs @ 16386

Last change on this file since 16386 was 16386, checked in by gkronber, 5 years ago

#2925 merged changes r15972:16382 from trunk to branch

File size: 7.6 KB
Line 
1#region License Information
2/* HeuristicLab
3 * Copyright (C) 2002-2018 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
4 *
5 * This file is part of HeuristicLab.
6 *
7 * HeuristicLab is free software: you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation, either version 3 of the License, or
10 * (at your option) any later version.
11 *
12 * HeuristicLab is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with HeuristicLab. If not, see <http://www.gnu.org/licenses/>.
19 */
20#endregion
21
22using System;
23using System.Collections.Generic;
24using System.Globalization;
25using System.Linq;
26using System.Text;
27using HeuristicLab.Common;
28using HeuristicLab.Core;
29using HeuristicLab.Encodings.SymbolicExpressionTreeEncoding;
30using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
31
32namespace HeuristicLab.Problems.DataAnalysis.Symbolic {
33  /// <summary>
34  /// Formats mathematical expressions in infix form. E.g. x1 * (3.0 * x2 + x3)
35  /// </summary>
36  [StorableClass]
37  [Item("Infix Symbolic Expression Tree Formatter", "A string formatter that converts symbolic expression trees to infix expressions.")]
38
39  public sealed class InfixExpressionFormatter : NamedItem, ISymbolicExpressionTreeStringFormatter {
40
41
42    [StorableConstructor]
43    private InfixExpressionFormatter(bool deserializing) : base(deserializing) { }
44    private InfixExpressionFormatter(InfixExpressionFormatter original, Cloner cloner) : base(original, cloner) { }
45    public InfixExpressionFormatter()
46      : base() {
47      Name = ItemName;
48      Description = ItemDescription;
49    }
50    public override IDeepCloneable Clone(Cloner cloner) {
51      return new InfixExpressionFormatter(this, cloner);
52    }
53
54    public string Format(ISymbolicExpressionTree symbolicExpressionTree) {
55      // skip root and start symbols
56      StringBuilder strBuilder = new StringBuilder();
57      FormatRecursively(symbolicExpressionTree.Root.GetSubtree(0).GetSubtree(0), strBuilder);
58      return strBuilder.ToString();
59    }
60
61    private void FormatRecursively(ISymbolicExpressionTreeNode node, StringBuilder strBuilder) {
62      if (node.SubtreeCount > 1) {
63        var token = GetToken(node.Symbol);
64        // operators
65        if (token == "+" || token == "-" || token == "OR" || token == "XOR" ||
66            token == "*" || token == "/" || token == "AND" ||
67            token == "^") {
68          strBuilder.Append("(");
69          FormatRecursively(node.Subtrees.First(), strBuilder);
70
71          foreach (var subtree in node.Subtrees.Skip(1)) {
72            strBuilder.Append(" ").Append(token).Append(" ");
73            FormatRecursively(subtree, strBuilder);
74          }
75          strBuilder.Append(")");
76        } else {
77          // function with multiple arguments
78          strBuilder.Append(token).Append("(");
79          FormatRecursively(node.Subtrees.First(), strBuilder);
80          foreach (var subtree in node.Subtrees.Skip(1)) {
81            strBuilder.Append(", ");
82            FormatRecursively(subtree, strBuilder);
83          }
84          strBuilder.Append(")");
85        }
86      } else if (node.SubtreeCount == 1) {
87        var token = GetToken(node.Symbol);
88        if (token == "-" || token == "NOT") {
89          strBuilder.Append("(").Append(token).Append("(");
90          FormatRecursively(node.GetSubtree(0), strBuilder);
91          strBuilder.Append("))");
92        } else if (token == "/") {
93          strBuilder.Append("1/");
94          FormatRecursively(node.GetSubtree(0), strBuilder);
95        } else if (token == "+" || token == "*") {
96          FormatRecursively(node.GetSubtree(0), strBuilder);
97        } else {
98          // function with only one argument
99          strBuilder.Append(token).Append("(");
100          FormatRecursively(node.GetSubtree(0), strBuilder);
101          strBuilder.Append(")");
102        }
103      } else {
104        // no subtrees
105        if (node.Symbol is LaggedVariable) {
106          var varNode = node as LaggedVariableTreeNode;
107          if (!varNode.Weight.IsAlmost(1.0)) {
108            strBuilder.Append("(");
109            strBuilder.AppendFormat(CultureInfo.InvariantCulture, "{0}", varNode.Weight);
110            strBuilder.Append("*");
111          }
112          strBuilder.Append("LAG(");
113          if (varNode.VariableName.Contains("'")) {
114            strBuilder.AppendFormat("\"{0}\"", varNode.VariableName);
115          } else {
116            strBuilder.AppendFormat("'{0}'", varNode.VariableName);
117          }
118          strBuilder.Append(", ")
119            .AppendFormat(CultureInfo.InvariantCulture, "{0}", varNode.Lag)
120            .Append(")");
121        } else if (node.Symbol is Variable) {
122          var varNode = node as VariableTreeNode;
123          if (!varNode.Weight.IsAlmost(1.0)) {
124            strBuilder.Append("(");
125            strBuilder.AppendFormat(CultureInfo.InvariantCulture, "{0}", varNode.Weight);
126            strBuilder.Append("*");
127          }
128          if (varNode.VariableName.Contains("'")) {
129            strBuilder.AppendFormat("\"{0}\"", varNode.VariableName);
130          } else {
131            strBuilder.AppendFormat("'{0}'", varNode.VariableName);
132          }
133          if (!varNode.Weight.IsAlmost(1.0)) {
134            strBuilder.Append(")");
135          }
136        } else if (node.Symbol is FactorVariable) {
137          var factorNode = node as FactorVariableTreeNode;
138          if (factorNode.VariableName.Contains("'")) {
139            strBuilder.AppendFormat("\"{0}\"", factorNode.VariableName);
140          } else {
141            strBuilder.AppendFormat("'{0}'", factorNode.VariableName);
142          }
143          strBuilder.AppendFormat("[{0}]",
144            string.Join(", ", factorNode.Weights.Select(w => w.ToString(CultureInfo.InvariantCulture))));
145        } else if (node.Symbol is BinaryFactorVariable) {
146          var factorNode = node as BinaryFactorVariableTreeNode;
147          if (!factorNode.Weight.IsAlmost(1.0)) {
148            strBuilder.Append("(");
149            strBuilder.AppendFormat(CultureInfo.InvariantCulture, "{0}", factorNode.Weight);
150            strBuilder.Append("*");
151          }
152          if (factorNode.VariableName.Contains("'")) {
153            strBuilder.AppendFormat("\"{0}\"", factorNode.VariableName);
154          } else {
155            strBuilder.AppendFormat("'{0}'", factorNode.VariableName);
156          }
157          strBuilder.Append(" = ");
158          if (factorNode.VariableValue.Contains("'")) {
159            strBuilder.AppendFormat("\"{0}\"", factorNode.VariableValue);
160          } else {
161            strBuilder.AppendFormat("'{0}'", factorNode.VariableValue);
162          }
163
164          if (!factorNode.Weight.IsAlmost(1.0)) {
165            strBuilder.Append(")");
166          }
167
168        } else if (node.Symbol is Constant) {
169          var constNode = node as ConstantTreeNode;
170          if (constNode.Value >= 0.0)
171            strBuilder.AppendFormat(CultureInfo.InvariantCulture, "{0}", constNode.Value);
172          else
173            strBuilder.AppendFormat(CultureInfo.InvariantCulture, "({0})", constNode.Value); // (-1
174        }
175      }
176    }
177
178    private string GetToken(ISymbol symbol) {
179      var tok = InfixExpressionParser.knownSymbols.GetBySecond(symbol).FirstOrDefault();
180      if (tok == null)
181        throw new ArgumentException(string.Format("Unknown symbol {0} found.", symbol.Name));
182      return tok;
183    }
184  }
185}
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