1 | using System.Collections;
|
---|
2 | using System.Collections.Generic;
|
---|
3 | using System.ComponentModel;
|
---|
4 | using System.Diagnostics;
|
---|
5 | using System.Linq;
|
---|
6 | using HeuristicLab.Algorithms.DataAnalysis.SymRegGrammarEnumeration.GrammarEnumeration;
|
---|
7 | using HeuristicLab.Common;
|
---|
8 | using HeuristicLab.Encodings.SymbolicExpressionTreeEncoding;
|
---|
9 | using HeuristicLab.Problems.DataAnalysis.Symbolic;
|
---|
10 |
|
---|
11 | namespace HeuristicLab.Algorithms.DataAnalysis.SymRegGrammarEnumeration {
|
---|
12 | public class Grammar {
|
---|
13 |
|
---|
14 | public Symbol StartSymbol;
|
---|
15 |
|
---|
16 | #region Symbols
|
---|
17 |
|
---|
18 | public VariableSymbol Var;
|
---|
19 |
|
---|
20 | public NonterminalSymbol Expr;
|
---|
21 | public NonterminalSymbol Term;
|
---|
22 | public NonterminalSymbol Factor;
|
---|
23 |
|
---|
24 | public TerminalSymbol Addition;
|
---|
25 | public TerminalSymbol Multiplication;
|
---|
26 |
|
---|
27 | #endregion
|
---|
28 |
|
---|
29 |
|
---|
30 | #region HL Symbols for Parsing ExpressionTrees
|
---|
31 |
|
---|
32 | private TypeCoherentExpressionGrammar symbolicExpressionGrammar;
|
---|
33 |
|
---|
34 | private ISymbol constSy;
|
---|
35 | private ISymbol varSy;
|
---|
36 |
|
---|
37 | private ISymbol addSy;
|
---|
38 | private ISymbol mulSy;
|
---|
39 | private ISymbol logSy;
|
---|
40 | private ISymbol expSy;
|
---|
41 | private ISymbol divSy;
|
---|
42 |
|
---|
43 | private ISymbol rootSy;
|
---|
44 | private ISymbol startSy;
|
---|
45 |
|
---|
46 | #endregion
|
---|
47 |
|
---|
48 | public Grammar(string[] variables) {
|
---|
49 | #region Define Symbols
|
---|
50 | Var = new VariableSymbol("var", variables);
|
---|
51 |
|
---|
52 | Expr = new NonterminalSymbol("Expr");
|
---|
53 | Term = new NonterminalSymbol("Term");
|
---|
54 | Factor = new NonterminalSymbol("Factor");
|
---|
55 |
|
---|
56 | Addition = new TerminalSymbol("+");
|
---|
57 | Multiplication = new TerminalSymbol("*");
|
---|
58 | #endregion
|
---|
59 |
|
---|
60 |
|
---|
61 | #region Production rules
|
---|
62 | // order of production is important, since they are accessed via index
|
---|
63 | // in memoization.
|
---|
64 | StartSymbol = Expr;
|
---|
65 |
|
---|
66 | Expr.AddProduction(Term, Expr, Addition);
|
---|
67 | Expr.AddProduction(Term);
|
---|
68 |
|
---|
69 | Term.AddProduction(Factor, Term, Multiplication);
|
---|
70 | Term.AddProduction(Factor);
|
---|
71 |
|
---|
72 | Factor.AddProduction(Var);
|
---|
73 | #endregion
|
---|
74 |
|
---|
75 | #region Parsing to SymbolicExpressionTree
|
---|
76 | symbolicExpressionGrammar = new TypeCoherentExpressionGrammar();
|
---|
77 | symbolicExpressionGrammar.ConfigureAsDefaultRegressionGrammar();
|
---|
78 |
|
---|
79 | constSy = symbolicExpressionGrammar.Symbols.OfType<Constant>().First();
|
---|
80 | varSy = symbolicExpressionGrammar.Symbols.OfType<Variable>().First();
|
---|
81 | addSy = symbolicExpressionGrammar.AllowedSymbols.OfType<Addition>().First();
|
---|
82 | mulSy = symbolicExpressionGrammar.AllowedSymbols.OfType<Multiplication>().First();
|
---|
83 | logSy = symbolicExpressionGrammar.AllowedSymbols.OfType<Logarithm>().First();
|
---|
84 | expSy = symbolicExpressionGrammar.AllowedSymbols.OfType<Exponential>().First();
|
---|
85 | divSy = symbolicExpressionGrammar.AllowedSymbols.OfType<Division>().First();
|
---|
86 |
|
---|
87 | rootSy = symbolicExpressionGrammar.AllowedSymbols.OfType<ProgramRootSymbol>().First();
|
---|
88 | startSy = symbolicExpressionGrammar.AllowedSymbols.OfType<StartSymbol>().First();
|
---|
89 |
|
---|
90 | #endregion
|
---|
91 | }
|
---|
92 |
|
---|
93 | /*
|
---|
94 | #region Memoize subtrees
|
---|
95 |
|
---|
96 | public void MemoizeSubtrees(SymbolString sentence) {
|
---|
97 | Stack<TerminalSymbol> parseStack = new Stack<TerminalSymbol>(sentence.OfType<TerminalSymbol>());
|
---|
98 |
|
---|
99 | // Parse root symbol "+"
|
---|
100 | MemoizeSubtreeExpression(parseStack);
|
---|
101 | }
|
---|
102 |
|
---|
103 | private SymbolString MemoizeSubtreeExpression(Stack<TerminalSymbol> parseStack) {
|
---|
104 | SymbolString subtree = new SymbolString();
|
---|
105 |
|
---|
106 | if (ReferenceEquals(parseStack.Peek(), Addition)) {
|
---|
107 | subtree.Add(parseStack.Pop());
|
---|
108 | subtree.InsertRange(0, MemoizeSubtreeExpression(parseStack));
|
---|
109 | subtree.InsertRange(0, MemoizeSubtreeTerm(parseStack));
|
---|
110 |
|
---|
111 | Expr.Alternatives[0].GeneratedSentences.Add(subtree);
|
---|
112 | } else {
|
---|
113 | subtree.InsertRange(0, MemoizeSubtreeTerm(parseStack));
|
---|
114 |
|
---|
115 | Expr.Alternatives[1].GeneratedSentences.Add(subtree);
|
---|
116 | }
|
---|
117 |
|
---|
118 | return subtree;
|
---|
119 | }
|
---|
120 |
|
---|
121 | private SymbolString MemoizeSubtreeTerm(Stack<TerminalSymbol> parseStack) {
|
---|
122 | SymbolString subtree = new SymbolString();
|
---|
123 |
|
---|
124 | if (ReferenceEquals(parseStack.Peek(), Multiplication)) {
|
---|
125 | subtree.Add(parseStack.Pop());
|
---|
126 | subtree.InsertRange(0, MemoizeSubtreeTerm(parseStack));
|
---|
127 | subtree.InsertRange(0, MemoizeSubtreeFactor(parseStack));
|
---|
128 |
|
---|
129 | Term.Alternatives[0].GeneratedSentences.Add(subtree);
|
---|
130 | } else {
|
---|
131 | subtree.InsertRange(0, MemoizeSubtreeFactor(parseStack));
|
---|
132 |
|
---|
133 | Term.Alternatives[1].GeneratedSentences.Add(subtree);
|
---|
134 | }
|
---|
135 |
|
---|
136 | return subtree;
|
---|
137 | }
|
---|
138 |
|
---|
139 | private SymbolString MemoizeSubtreeFactor(Stack<TerminalSymbol> parseStack) {
|
---|
140 | SymbolString subtree = new SymbolString(MemoizeSubtreeVar(parseStack));
|
---|
141 |
|
---|
142 | Factor.Alternatives[0].GeneratedSentences.Add(subtree);
|
---|
143 | return subtree;
|
---|
144 | }
|
---|
145 |
|
---|
146 | private SymbolString MemoizeSubtreeVar(Stack<TerminalSymbol> parseStack) {
|
---|
147 | SymbolString subtree = new SymbolString(parseStack.Pop().ToEnumerable());
|
---|
148 |
|
---|
149 | // ... not really
|
---|
150 | //Var.Alternatives[0].GeneratedSentences.Add(subtree);
|
---|
151 | return subtree;
|
---|
152 | }
|
---|
153 |
|
---|
154 |
|
---|
155 | #endregion
|
---|
156 | */
|
---|
157 |
|
---|
158 | #region Hashing
|
---|
159 | public int CalcHashCode(SymbolString sentence) {
|
---|
160 | Debug.Assert(sentence.Any(), "Trying to evaluate empty sentence!");
|
---|
161 | Debug.Assert(sentence.All(s => s is TerminalSymbol), "Trying to evaluate symbol sequence with nonterminalsymbols!");
|
---|
162 |
|
---|
163 | Stack<TerminalSymbol> parseStack = new Stack<TerminalSymbol>(sentence.OfType<TerminalSymbol>());
|
---|
164 |
|
---|
165 | int[] subtreeHashes = GetSubtreeHashes(parseStack.Pop(), parseStack);
|
---|
166 | return AggregateHashes(subtreeHashes);
|
---|
167 | }
|
---|
168 |
|
---|
169 | private int[] GetSubtreeHashes(TerminalSymbol currentSymbol, Stack<TerminalSymbol> parseStack) {
|
---|
170 | List<int> childHashes = null;
|
---|
171 |
|
---|
172 | if (Var.VariableTerminalSymbols.Contains(currentSymbol)) {
|
---|
173 | childHashes = currentSymbol.StringRepresentation.GetHashCode().ToEnumerable().ToList();
|
---|
174 |
|
---|
175 | } else if (ReferenceEquals(currentSymbol, Multiplication)) {
|
---|
176 | // MULTIPLICATION
|
---|
177 | childHashes = new List<int>();
|
---|
178 |
|
---|
179 | // First subtree
|
---|
180 | TerminalSymbol firstSubtreeRoot = parseStack.Pop();
|
---|
181 | int[] firstSubtreeHashes = GetSubtreeHashes(firstSubtreeRoot, parseStack);
|
---|
182 |
|
---|
183 | if (ReferenceEquals(firstSubtreeRoot, Multiplication)) {
|
---|
184 | childHashes.AddRange(firstSubtreeHashes);
|
---|
185 | } else {
|
---|
186 | childHashes.Add(AggregateHashes(firstSubtreeHashes));
|
---|
187 | }
|
---|
188 |
|
---|
189 | // Second subtree
|
---|
190 | TerminalSymbol secondSubtreeRoot = parseStack.Pop();
|
---|
191 | int[] secondSubtreeHashes = GetSubtreeHashes(secondSubtreeRoot, parseStack);
|
---|
192 |
|
---|
193 | if (ReferenceEquals(secondSubtreeRoot, Multiplication)) {
|
---|
194 | childHashes.AddRange(secondSubtreeHashes);
|
---|
195 | } else {
|
---|
196 | childHashes.Add(AggregateHashes(secondSubtreeHashes));
|
---|
197 | }
|
---|
198 |
|
---|
199 | // Sort due to commutativity
|
---|
200 | childHashes.Sort();
|
---|
201 |
|
---|
202 |
|
---|
203 |
|
---|
204 | } else if (ReferenceEquals(currentSymbol, Addition)) {
|
---|
205 | // ADDITION
|
---|
206 | HashSet<int> uniqueChildHashes = new HashSet<int>();
|
---|
207 |
|
---|
208 | TerminalSymbol firstSubtreeRoot = parseStack.Pop();
|
---|
209 | int[] firstSubtreeHashes = GetSubtreeHashes(firstSubtreeRoot, parseStack);
|
---|
210 |
|
---|
211 | // First subtree
|
---|
212 | if (ReferenceEquals(firstSubtreeRoot, Addition)) {
|
---|
213 | uniqueChildHashes.UnionWith(firstSubtreeHashes);
|
---|
214 | } else {
|
---|
215 | uniqueChildHashes.Add(AggregateHashes(firstSubtreeHashes));
|
---|
216 | }
|
---|
217 |
|
---|
218 | // Second subtree
|
---|
219 | TerminalSymbol secondSubtreeRoot = parseStack.Pop();
|
---|
220 | int[] secondSubtreeHashes = GetSubtreeHashes(secondSubtreeRoot, parseStack);
|
---|
221 |
|
---|
222 | if (ReferenceEquals(secondSubtreeRoot, Addition)) {
|
---|
223 | uniqueChildHashes.UnionWith(secondSubtreeHashes);
|
---|
224 | } else {
|
---|
225 | uniqueChildHashes.Add(AggregateHashes(secondSubtreeHashes));
|
---|
226 | }
|
---|
227 |
|
---|
228 | childHashes = uniqueChildHashes.ToList();
|
---|
229 | childHashes.Sort();
|
---|
230 | }
|
---|
231 |
|
---|
232 | Debug.Assert(childHashes != null, "Sentence not hashable!");
|
---|
233 | return childHashes.ToArray();
|
---|
234 | }
|
---|
235 |
|
---|
236 | private int AggregateHashes(IEnumerable<int> hashes) {
|
---|
237 | return hashes.Aggregate(0, (result, ti) => ((result << 5) + result) ^ ti.GetHashCode());
|
---|
238 | }
|
---|
239 | #endregion
|
---|
240 |
|
---|
241 | #region Parse to SymbolicExpressionTree
|
---|
242 | public SymbolicExpressionTree ParseSymbolicExpressionTree(SymbolString sentence) {
|
---|
243 | Debug.Assert(sentence.Any(), "Trying to evaluate empty sentence!");
|
---|
244 | Debug.Assert(sentence.All(s => s is TerminalSymbol), "Trying to evaluate symbol sequence with nonterminalsymbols!");
|
---|
245 |
|
---|
246 | symbolicExpressionGrammar.ConfigureAsDefaultRegressionGrammar();
|
---|
247 |
|
---|
248 | var rootNode = rootSy.CreateTreeNode();
|
---|
249 | var startNode = startSy.CreateTreeNode();
|
---|
250 | rootNode.AddSubtree(startNode);
|
---|
251 |
|
---|
252 | Stack<TerminalSymbol> parseStack = new Stack<TerminalSymbol>(sentence.OfType<TerminalSymbol>());
|
---|
253 | startNode.AddSubtree(ParseSymbolicExpressionTree(parseStack));
|
---|
254 |
|
---|
255 | return new SymbolicExpressionTree(rootNode);
|
---|
256 | }
|
---|
257 |
|
---|
258 | public ISymbolicExpressionTreeNode ParseSymbolicExpressionTree(Stack<TerminalSymbol> parseStack) {
|
---|
259 | TerminalSymbol currentSymbol = parseStack.Pop();
|
---|
260 |
|
---|
261 | ISymbolicExpressionTreeNode parsedSubTree = null;
|
---|
262 |
|
---|
263 | if (ReferenceEquals(currentSymbol, Addition)) {
|
---|
264 | parsedSubTree = addSy.CreateTreeNode();
|
---|
265 | parsedSubTree.AddSubtree(ParseSymbolicExpressionTree(parseStack)); // left part
|
---|
266 | parsedSubTree.AddSubtree(ParseSymbolicExpressionTree(parseStack)); // right part
|
---|
267 |
|
---|
268 | } else if (ReferenceEquals(currentSymbol, Multiplication)) {
|
---|
269 | parsedSubTree = mulSy.CreateTreeNode();
|
---|
270 | parsedSubTree.AddSubtree(ParseSymbolicExpressionTree(parseStack)); // left part
|
---|
271 | parsedSubTree.AddSubtree(ParseSymbolicExpressionTree(parseStack)); // right part
|
---|
272 |
|
---|
273 | } else if (Var.VariableTerminalSymbols.Contains(currentSymbol)) {
|
---|
274 | VariableTreeNode varNode = (VariableTreeNode)varSy.CreateTreeNode();
|
---|
275 | varNode.Weight = 1.0;
|
---|
276 | varNode.VariableName = currentSymbol.StringRepresentation;
|
---|
277 | parsedSubTree = varNode;
|
---|
278 | }
|
---|
279 |
|
---|
280 | Debug.Assert(parsedSubTree != null);
|
---|
281 | return parsedSubTree;
|
---|
282 | }
|
---|
283 | #endregion
|
---|
284 | }
|
---|
285 | }
|
---|