1 | #region License Information
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2 | /* HeuristicLab
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3 | * Copyright (C) 2002-2016 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
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4 | *
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5 | * This file is part of HeuristicLab.
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6 | *
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7 | * HeuristicLab is free software: you can redistribute it and/or modify
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8 | * it under the terms of the GNU General Public License as published by
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9 | * the Free Software Foundation, either version 3 of the License, or
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10 | * (at your option) any later version.
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11 | *
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12 | * HeuristicLab is distributed in the hope that it will be useful,
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13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of
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14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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15 | * GNU General Public License for more details.
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16 | *
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17 | * You should have received a copy of the GNU General Public License
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18 | * along with HeuristicLab. If not, see <http://www.gnu.org/licenses/>.
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19 | */
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20 | #endregion
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21 |
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22 | using System;
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23 | using System.Collections.Generic;
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24 | using System.Globalization;
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25 | using System.Linq;
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26 | using System.Text;
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27 | using HeuristicLab.Common;
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28 | using HeuristicLab.Core;
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29 | using HeuristicLab.Encodings.SymbolicExpressionTreeEncoding;
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30 | using HeuristicLab.Persistence;
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31 |
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32 | namespace HeuristicLab.Problems.DataAnalysis.Symbolic {
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33 | /// <summary>
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34 | /// Formats mathematical expressions in infix form. E.g. x1 * (3.0 * x2 + x3)
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35 | /// </summary>
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36 | [StorableType("7f57939a-3dac-48a5-848e-d86aa111b566")]
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37 | [Item("Infix Symbolic Expression Tree Formatter", "A string formatter that converts symbolic expression trees to infix expressions.")]
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38 |
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39 | public sealed class InfixExpressionFormatter : NamedItem, ISymbolicExpressionTreeStringFormatter {
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40 |
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41 |
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42 | [StorableConstructor]
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43 | private InfixExpressionFormatter(StorableConstructorFlag deserializing) : base(deserializing) { }
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44 | private InfixExpressionFormatter(InfixExpressionFormatter original, Cloner cloner) : base(original, cloner) { }
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45 | public InfixExpressionFormatter()
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46 | : base() {
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47 | Name = ItemName;
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48 | Description = ItemDescription;
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49 | }
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50 | public override IDeepCloneable Clone(Cloner cloner) {
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51 | return new InfixExpressionFormatter(this, cloner);
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52 | }
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53 |
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54 | public string Format(ISymbolicExpressionTree symbolicExpressionTree) {
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55 | // skip root and start symbols
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56 | StringBuilder strBuilder = new StringBuilder();
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57 | FormatRecursively(symbolicExpressionTree.Root.GetSubtree(0).GetSubtree(0), strBuilder);
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58 | return strBuilder.ToString();
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59 | }
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60 |
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61 | private void FormatRecursively(ISymbolicExpressionTreeNode node, StringBuilder strBuilder) {
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62 | if (node.SubtreeCount > 1) {
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63 | var token = GetToken(node.Symbol);
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64 | if (token == "+" || token == "-" || token == "OR" || token == "XOR") {
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65 | strBuilder.Append("(");
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66 | FormatRecursively(node.Subtrees.First(), strBuilder);
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67 |
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68 | foreach (var subtree in node.Subtrees.Skip(1)) {
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69 | strBuilder.Append(" ").Append(token).Append(" ");
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70 | FormatRecursively(subtree, strBuilder);
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71 | }
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72 | strBuilder.Append(")");
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73 |
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74 | } else if (token == "*" || token == "/" || token == "AND") {
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75 | strBuilder.Append("(");
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76 | FormatRecursively(node.Subtrees.First(), strBuilder);
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77 |
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78 | foreach (var subtree in node.Subtrees.Skip(1)) {
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79 | strBuilder.Append(" ").Append(token).Append(" ");
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80 | FormatRecursively(subtree, strBuilder);
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81 | }
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82 | strBuilder.Append(")");
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83 | } else {
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84 | // function with multiple arguments
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85 | strBuilder.Append(token).Append("(");
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86 | FormatRecursively(node.Subtrees.First(), strBuilder);
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87 | foreach (var subtree in node.Subtrees.Skip(1)) {
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88 | strBuilder.Append(", ");
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89 | FormatRecursively(subtree, strBuilder);
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90 | }
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91 | strBuilder.Append(")");
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92 | }
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93 | } else if (node.SubtreeCount == 1) {
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94 | var token = GetToken(node.Symbol);
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95 | if (token == "-" || token == "NOT") {
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96 | strBuilder.Append("(").Append(token).Append("(");
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97 | FormatRecursively(node.GetSubtree(0), strBuilder);
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98 | strBuilder.Append("))");
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99 | } else if (token == "/") {
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100 | strBuilder.Append("1/");
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101 | FormatRecursively(node.GetSubtree(0), strBuilder);
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102 | } else if (token == "+" || token == "*") {
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103 | FormatRecursively(node.GetSubtree(0), strBuilder);
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104 | } else {
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105 | // function with only one argument
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106 | strBuilder.Append(token).Append("(");
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107 | FormatRecursively(node.GetSubtree(0), strBuilder);
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108 | strBuilder.Append(")");
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109 | }
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110 | } else {
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111 | // no subtrees
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112 | if (node.Symbol is LaggedVariable) {
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113 | var varNode = node as LaggedVariableTreeNode;
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114 | if (!varNode.Weight.IsAlmost(1.0)) {
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115 | strBuilder.Append("(");
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116 | strBuilder.AppendFormat(CultureInfo.InvariantCulture, "{0}", varNode.Weight);
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117 | strBuilder.Append("*");
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118 | }
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119 | strBuilder.Append("LAG(");
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120 | if (varNode.VariableName.Contains("'")) {
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121 | strBuilder.AppendFormat("\"{0}\"", varNode.VariableName);
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122 | } else {
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123 | strBuilder.AppendFormat("'{0}'", varNode.VariableName);
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124 | }
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125 | strBuilder.Append(", ")
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126 | .AppendFormat(CultureInfo.InvariantCulture, "{0}", varNode.Lag)
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127 | .Append(")");
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128 | } else if (node.Symbol is Variable) {
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129 | var varNode = node as VariableTreeNode;
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130 | if (!varNode.Weight.IsAlmost(1.0)) {
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131 | strBuilder.Append("(");
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132 | strBuilder.AppendFormat(CultureInfo.InvariantCulture, "{0}", varNode.Weight);
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133 | strBuilder.Append("*");
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134 | }
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135 | if (varNode.VariableName.Contains("'")) {
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136 | strBuilder.AppendFormat("\"{0}\"", varNode.VariableName);
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137 | } else {
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138 | strBuilder.AppendFormat("'{0}'", varNode.VariableName);
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139 | }
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140 | if (!varNode.Weight.IsAlmost(1.0)) {
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141 | strBuilder.Append(")");
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142 | }
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143 | } else if (node.Symbol is FactorVariable) {
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144 | var factorNode = node as FactorVariableTreeNode;
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145 | if (factorNode.VariableName.Contains("'")) {
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146 | strBuilder.AppendFormat("\"{0}\"", factorNode.VariableName);
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147 | } else {
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148 | strBuilder.AppendFormat("'{0}'", factorNode.VariableName);
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149 | }
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150 | strBuilder.AppendFormat("[{0}]",
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151 | string.Join(", ", factorNode.Weights.Select(w => w.ToString(CultureInfo.InvariantCulture))));
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152 | } else if (node.Symbol is BinaryFactorVariable) {
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153 | var factorNode = node as BinaryFactorVariableTreeNode;
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154 | if (!factorNode.Weight.IsAlmost(1.0)) {
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155 | strBuilder.Append("(");
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156 | strBuilder.AppendFormat(CultureInfo.InvariantCulture, "{0}", factorNode.Weight);
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157 | strBuilder.Append("*");
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158 | }
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159 | if (factorNode.VariableName.Contains("'")) {
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160 | strBuilder.AppendFormat("\"{0}\"", factorNode.VariableName);
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161 | } else {
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162 | strBuilder.AppendFormat("'{0}'", factorNode.VariableName);
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163 | }
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164 | strBuilder.Append(" = ");
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165 | if (factorNode.VariableValue.Contains("'")) {
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166 | strBuilder.AppendFormat("\"{0}\"", factorNode.VariableValue);
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167 | } else {
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168 | strBuilder.AppendFormat("'{0}'", factorNode.VariableValue);
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169 | }
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170 |
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171 | if (!factorNode.Weight.IsAlmost(1.0)) {
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172 | strBuilder.Append(")");
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173 | }
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174 |
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175 | } else if (node.Symbol is Constant) {
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176 | var constNode = node as ConstantTreeNode;
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177 | if (constNode.Value >= 0.0)
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178 | strBuilder.AppendFormat(CultureInfo.InvariantCulture, "{0}", constNode.Value);
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179 | else
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180 | strBuilder.AppendFormat(CultureInfo.InvariantCulture, "({0})", constNode.Value); // (-1
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181 | }
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182 | }
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183 | }
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184 |
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185 | private string GetToken(ISymbol symbol) {
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186 | var tok = InfixExpressionParser.knownSymbols.GetBySecond(symbol).SingleOrDefault();
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187 | if (tok == null)
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188 | throw new ArgumentException(string.Format("Unknown symbol {0} found.", symbol.Name));
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189 | return tok;
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190 | }
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191 | }
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192 | }
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