[14409] | 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.Core;
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| 28 | using HeuristicLab.Random;
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| 29 |
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| 30 | namespace HeuristicLab.ExpressionGenerator {
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[14505] | 31 | public class Expression : IExpression {
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| 32 | // unique name for each expression
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| 33 | public string Name { get; set; }
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| 34 | // optional label (non-unique) - useful for string (infix) representations
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| 35 | public string Label { get; set; }
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[14409] | 36 |
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[14505] | 37 | public ExpressionType Type { get; private set; }
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[14409] | 38 |
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[14505] | 39 | private readonly List<Expression> arguments;
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| 40 | public IEnumerable<Expression> Arguments {
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| 41 | get { return arguments ?? Enumerable.Empty<Expression>(); }
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| 42 | }
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[14409] | 43 |
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[14505] | 44 | public IRandom Distribution { get; private set; }
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[14409] | 45 |
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[14505] | 46 | public Func<IEnumerable<double>, double> Transform { get; private set; }
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[14409] | 47 |
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[14505] | 48 | public double Value { get; private set; }
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[14409] | 49 |
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[14505] | 50 | public Expression(string name, double value) {
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| 51 | Type = ExpressionType.Constant;
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| 52 | Value = value;
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| 53 | Name = name;
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| 54 | }
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[14409] | 55 |
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[14505] | 56 | public Expression(string name, IRandom distribution) {
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| 57 | Type = ExpressionType.RandomVariable;
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| 58 | Distribution = distribution;
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| 59 | Name = name;
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| 60 | }
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[14409] | 61 |
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[14505] | 62 | public Expression(string name, Func<IEnumerable<double>, double> transform, IEnumerable<Expression> arguments) {
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| 63 | Type = ExpressionType.Function;
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| 64 | Transform = transform;
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| 65 | this.arguments = this.arguments ?? new List<Expression>();
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| 66 | this.arguments.AddRange(arguments);
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| 67 | Name = name;
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| 68 | }
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[14409] | 69 |
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[14505] | 70 | public static Expression Constant(string name, double value) {
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| 71 | return new Expression(name, value);
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| 72 | }
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[14409] | 73 |
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[14505] | 74 | public static Expression RandomVariable(string name, IRandom distribution) {
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| 75 | return new Expression(name, distribution);
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| 76 | }
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[14409] | 77 |
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[14505] | 78 | public static Expression Function(string name, Func<IEnumerable<double>, double> transform, IEnumerable<Expression> arguments) {
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| 79 | return new Expression(name, transform, arguments);
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| 80 | }
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[14409] | 81 |
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[14505] | 82 | public override string ToString() {
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| 83 | var sb = new StringBuilder();
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[14409] | 84 |
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[14505] | 85 | switch (Type) {
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| 86 | case ExpressionType.Constant:
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| 87 | sb.Append(Value.ToString("0.000", CultureInfo.CurrentCulture));
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| 88 | break;
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| 89 | case ExpressionType.RandomVariable:
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| 90 | sb.Append(string.Format("{0} ~ {1}", Name, GetStringDescription(Distribution)));
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| 91 | break;
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| 92 | case ExpressionType.Function:
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| 93 | sb.Append(string.Format("{0} = f(", Name));
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| 94 | if (Arguments.Any()) {
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| 95 | for (int i = 0; i < arguments.Count - 1; ++i)
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| 96 | sb.Append(string.Format("{0}, ", arguments[i].Name));
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| 97 | sb.Append(string.Format("{0})", arguments.Last().Name));
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| 98 | }
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| 99 | break;
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| 100 | }
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[14409] | 101 |
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[14505] | 102 | return sb.ToString();
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| 103 | }
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[14409] | 104 |
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[14505] | 105 | public string PrintInfix() {
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| 106 | var sb = new StringBuilder();
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| 107 | switch (Type) {
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| 108 | case ExpressionType.Constant:
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| 109 | sb.Append(Value < 0
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| 110 | ? string.Format("(- {0})", Math.Abs(Value).ToString("0.000", CultureInfo.CurrentCulture))
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| 111 | : Value.ToString("0.000", CultureInfo.CurrentCulture));
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| 112 | break;
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| 113 | case ExpressionType.RandomVariable:
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| 114 | sb.Append(Name);
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| 115 | break;
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| 116 | case ExpressionType.Function:
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| 117 | if (!Arguments.Any())
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| 118 | break;
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| 119 | var args = Arguments.ToList();
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| 120 | // the Label should be known to the infix parser
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| 121 | if (Label == "+" || Label == "-" || Label == "*" || Label == "/") {
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| 122 | if (args.Count == 1) {
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[14520] | 123 | sb.Append(string.Format(Label == "/" ? "1 / {0}" : "{0}", args[0].PrintInfix()));
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[14505] | 124 | } else {
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[14520] | 125 | if (Label == "/") {
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| 126 | sb.Append(string.Format("{0} / ", args[0].PrintInfix()));
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| 127 | var remaining = args.Count - 1;
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| 128 | if (remaining == 1)
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| 129 | sb.Append(args[1].PrintInfix());
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| 130 | else {
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| 131 | sb.Append("(");
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| 132 | var last = args.Last();
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| 133 | for (int i = 1; i < args.Count - 1; ++i) {
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| 134 | var arg = args[i];
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| 135 | sb.Append(string.Format("{0} {1} ", arg.PrintInfix(), "*"));
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| 136 | }
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| 137 | sb.Append(string.Format("{0})", last.PrintInfix()));
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| 138 | }
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| 139 | } else {
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| 140 | sb.Append("(");
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| 141 | var last = args.Last();
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| 142 | for (int i = 0; i < args.Count - 1; ++i) {
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| 143 | var arg = args[i];
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| 144 | sb.Append(string.Format("{0} {1} ", arg.PrintInfix(), Label));
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| 145 | }
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| 146 | sb.Append(string.Format("{0})", last.PrintInfix()));
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[14505] | 147 | }
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[14480] | 148 | }
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[14505] | 149 | } else {
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| 150 | sb.Append(string.Format("{0}(", Label));
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| 151 | var last = args.Last();
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| 152 | for (int i = 0; i < args.Count - 1; ++i) {
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| 153 | var arg = args[i];
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[14520] | 154 | sb.Append(string.Format("{0}, ", arg.PrintInfix()));
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[14505] | 155 | }
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| 156 | sb.Append(string.Format("{0})", last.PrintInfix()));
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| 157 | }
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| 158 | break;
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| 159 | }
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| 160 | return sb.ToString();
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| 161 | }
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[14448] | 162 |
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[14505] | 163 | public string PrintDot() {
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| 164 | var stack = new Stack<Expression>();
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| 165 | stack.Push(this);
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[14448] | 166 |
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[14505] | 167 | var sb = new StringBuilder();
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| 168 | sb.AppendLine("digraph g {");
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[14410] | 169 |
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[14505] | 170 | while (stack.Count > 0) {
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| 171 | var top = stack.Pop();
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[14410] | 172 |
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[14505] | 173 | if (!top.Arguments.Any())
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| 174 | continue;
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[14410] | 175 |
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[14505] | 176 | foreach (var arg in top.Arguments) {
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| 177 | var from = top.Arguments.Any() ? top.Name : top.ToString();
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| 178 | var to = arg.Arguments.Any() ? arg.Name : arg.ToString();
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| 179 | sb.AppendLine(string.Format("\"{0}\" -> \"{1}\";", from, to));
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| 180 | stack.Push(arg);
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[14410] | 181 | }
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[14505] | 182 | }
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[14410] | 183 |
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[14505] | 184 | sb.AppendLine("}");
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| 185 | return sb.ToString();
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| 186 | }
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[14410] | 187 |
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[14505] | 188 | private static string GetStringDescription(IRandom random) {
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| 189 | var normal = random as NormalDistributedRandom;
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| 190 | if (normal != null)
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| 191 | return string.Format("N({0}, {1})", normal.Mu, normal.Sigma);
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[14409] | 192 |
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[14505] | 193 | var uniform = random as UniformDistributedRandom;
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| 194 | if (uniform != null)
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| 195 | return string.Format("U({0}, {1})", uniform.Min, uniform.Max);
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[14409] | 196 |
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[14505] | 197 | var gamma = random as GammaDistributedRandom;
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| 198 | if (gamma != null)
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| 199 | return string.Format("G({0}, {1})", gamma.Shape, gamma.Rate);
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| 200 |
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| 201 | return random.ToString();
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[14409] | 202 | }
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[14505] | 203 | }
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[14409] | 204 | } |
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