source: trunk/sources/HeuristicLab.Problems.DataAnalysis.Symbolic.Views/3.4/InteractiveSymbolicDataAnalysisSolutionSimplifierView.cs @ 14494

Last change on this file since 14494 was 14494, checked in by bburlacu, 4 years ago

#2710: Extend tree validity test in the InteractiveSymbolicDataAnalysisSolutionSimplifierView to test if all the variable names in the tree are contained in the solution problem data.

File size: 12.5 KB
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1#region License Information
2/* HeuristicLab
3 * Copyright (C) 2002-2016 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.Drawing;
25using System.Linq;
26using System.Windows.Forms;
27using HeuristicLab.Common;
28using HeuristicLab.Encodings.SymbolicExpressionTreeEncoding;
29using HeuristicLab.Encodings.SymbolicExpressionTreeEncoding.Views;
30using HeuristicLab.MainForm.WindowsForms;
31
32namespace HeuristicLab.Problems.DataAnalysis.Symbolic.Views {
33  public abstract partial class InteractiveSymbolicDataAnalysisSolutionSimplifierView : AsynchronousContentView {
34    private Dictionary<ISymbolicExpressionTreeNode, ISymbolicExpressionTreeNode> foldedNodes;
35    private Dictionary<ISymbolicExpressionTreeNode, ISymbolicExpressionTreeNode> changedNodes;
36    private Dictionary<ISymbolicExpressionTreeNode, double> nodeImpacts;
37
38    private enum TreeState { Valid, Invalid }
39    private TreeState treeState;
40
41    protected InteractiveSymbolicDataAnalysisSolutionSimplifierView() {
42      InitializeComponent();
43      foldedNodes = new Dictionary<ISymbolicExpressionTreeNode, ISymbolicExpressionTreeNode>();
44      changedNodes = new Dictionary<ISymbolicExpressionTreeNode, ISymbolicExpressionTreeNode>();
45      nodeImpacts = new Dictionary<ISymbolicExpressionTreeNode, double>();
46      this.Caption = "Interactive Solution Simplifier";
47
48      // initialize the tree modifier that will be used to perform edit operations over the tree
49      treeChart.ModifyTree = Modify;
50    }
51
52    /// <summary>
53    /// Remove, Replace or Insert subtrees
54    /// </summary>
55    /// <param name="tree">The symbolic expression tree</param>
56    /// <param name="parent">The insertion point (ie, the parent node who will receive a new child)</param>
57    /// <param name="oldChild">The subtree to be replaced</param>
58    /// <param name="newChild">The replacement subtree</param>
59    /// <param name="removeSubtree">Flag used to indicate if whole subtrees should be removed (default behavior), or just the subtree root</param>
60    private void Modify(ISymbolicExpressionTree tree, ISymbolicExpressionTreeNode parent,
61      ISymbolicExpressionTreeNode oldChild, ISymbolicExpressionTreeNode newChild, bool removeSubtree = true) {
62      if (oldChild == null && newChild == null)
63        throw new ArgumentNullException("Cannot deduce operation type from the arguments. Please provide non null operands.");
64      if (oldChild == null) {
65        // insertion operation
66        parent.AddSubtree(newChild);
67        newChild.Parent = parent;
68      } else if (newChild == null) {
69        // removal operation
70        parent.RemoveSubtree(parent.IndexOfSubtree(oldChild));
71        if (!removeSubtree) {
72          for (int i = oldChild.SubtreeCount - 1; i >= 0; --i) {
73            var subtree = oldChild.GetSubtree(i);
74            oldChild.RemoveSubtree(i);
75            parent.AddSubtree(subtree);
76          }
77        }
78      } else {
79        // replacement operation
80        var replacementIndex = parent.IndexOfSubtree(oldChild);
81        parent.RemoveSubtree(replacementIndex);
82        parent.InsertSubtree(replacementIndex, newChild);
83        newChild.Parent = parent;
84        if (changedNodes.ContainsKey(oldChild)) {
85          changedNodes.Add(newChild, changedNodes[oldChild]); // so that on double click the original node is restored
86          changedNodes.Remove(oldChild);
87        } else {
88          changedNodes.Add(newChild, oldChild);
89        }
90      }
91      treeState = IsValid(tree) ? TreeState.Valid : TreeState.Invalid;
92      switch (treeState) {
93        case TreeState.Valid:
94          this.grpViewHost.Enabled = true;
95          UpdateModel(Content.Model.SymbolicExpressionTree);
96          break;
97        case TreeState.Invalid:
98          this.grpViewHost.Enabled = false;
99          break;
100      }
101    }
102
103    // the optimizer always assumes 2 children for multiplication and addition nodes
104    // thus, we enforce that the tree stays valid so that the constant optimization won't throw an exception
105    // by returning 2 as the minimum allowed arity for addition and multiplication symbols
106    private readonly Func<ISymbol, int> GetMinArity = symbol => {
107      var min = symbol.MinimumArity;
108      if (symbol is Multiplication || symbol is Division) return Math.Max(2, min);
109      return min;
110    };
111    private bool IsValid(ISymbolicExpressionTree tree) {
112      treeChart.Tree = tree;
113      treeChart.Repaint();
114      // check if all nodes have a legal arity
115      var nodes = tree.IterateNodesPostfix().ToList();
116      bool valid = !nodes.Any(node => node.SubtreeCount < GetMinArity(node.Symbol) || node.SubtreeCount > node.Symbol.MaximumArity);
117
118      if (valid) {
119        // check if all variables are contained in the dataset
120        var variables = new HashSet<string>(Content.ProblemData.Dataset.DoubleVariables);
121        valid = nodes.OfType<VariableTreeNode>().All(x => variables.Contains(x.VariableName));
122      }
123
124      if (valid) {
125        btnOptimizeConstants.Enabled = true;
126        btnSimplify.Enabled = true;
127        treeStatusValue.Visible = false;
128      } else {
129        btnOptimizeConstants.Enabled = false;
130        btnSimplify.Enabled = false;
131        treeStatusValue.Visible = true;
132      }
133      this.Refresh();
134      return valid;
135    }
136
137    public new ISymbolicDataAnalysisSolution Content {
138      get { return (ISymbolicDataAnalysisSolution)base.Content; }
139      set { base.Content = value; }
140    }
141
142    protected override void RegisterContentEvents() {
143      base.RegisterContentEvents();
144      Content.ModelChanged += Content_Changed;
145      Content.ProblemDataChanged += Content_Changed;
146      treeChart.Repainted += treeChart_Repainted;
147    }
148    protected override void DeregisterContentEvents() {
149      base.DeregisterContentEvents();
150      Content.ModelChanged -= Content_Changed;
151      Content.ProblemDataChanged -= Content_Changed;
152      treeChart.Repainted -= treeChart_Repainted;
153    }
154
155    private void Content_Changed(object sender, EventArgs e) {
156      UpdateView();
157    }
158
159    protected override void OnContentChanged() {
160      base.OnContentChanged();
161      foldedNodes = new Dictionary<ISymbolicExpressionTreeNode, ISymbolicExpressionTreeNode>();
162      UpdateView();
163      viewHost.Content = this.Content;
164    }
165
166    private void treeChart_Repainted(object sender, EventArgs e) {
167      if (nodeImpacts != null && nodeImpacts.Count > 0)
168        PaintNodeImpacts();
169    }
170
171    private void UpdateView() {
172      if (Content == null || Content.Model == null || Content.ProblemData == null) return;
173      var tree = Content.Model.SymbolicExpressionTree;
174      treeChart.Tree = tree.Root.SubtreeCount > 1 ? new SymbolicExpressionTree(tree.Root) : new SymbolicExpressionTree(tree.Root.GetSubtree(0).GetSubtree(0));
175
176      var impactAndReplacementValues = CalculateImpactAndReplacementValues(tree);
177      var replacementValues = impactAndReplacementValues.ToDictionary(x => x.Key, x => x.Value.Item2);
178      foreach (var pair in replacementValues.Where(pair => !(pair.Key is ConstantTreeNode))) {
179        foldedNodes[pair.Key] = MakeConstantTreeNode(pair.Value);
180      }
181      nodeImpacts = impactAndReplacementValues.ToDictionary(x => x.Key, x => x.Value.Item1);
182      PaintNodeImpacts();
183    }
184
185    protected abstract Dictionary<ISymbolicExpressionTreeNode, double> CalculateReplacementValues(ISymbolicExpressionTree tree);
186    protected abstract Dictionary<ISymbolicExpressionTreeNode, double> CalculateImpactValues(ISymbolicExpressionTree tree);
187    protected abstract Dictionary<ISymbolicExpressionTreeNode, Tuple<double, double>> CalculateImpactAndReplacementValues(ISymbolicExpressionTree tree);
188    protected abstract void UpdateModel(ISymbolicExpressionTree tree);
189
190    private static ConstantTreeNode MakeConstantTreeNode(double value) {
191      var constant = new Constant { MinValue = value - 1, MaxValue = value + 1 };
192      var constantTreeNode = (ConstantTreeNode)constant.CreateTreeNode();
193      constantTreeNode.Value = value;
194      return constantTreeNode;
195    }
196
197    private void treeChart_SymbolicExpressionTreeNodeDoubleClicked(object sender, MouseEventArgs e) {
198      if (treeState == TreeState.Invalid) return;
199      var visualNode = (VisualTreeNode<ISymbolicExpressionTreeNode>)sender;
200      if (visualNode.Content == null) { throw new Exception("VisualNode content cannot be null."); }
201      var symbExprTreeNode = (SymbolicExpressionTreeNode)visualNode.Content;
202      var tree = Content.Model.SymbolicExpressionTree;
203      var parent = symbExprTreeNode.Parent;
204      int indexOfSubtree = parent.IndexOfSubtree(symbExprTreeNode);
205      if (changedNodes.ContainsKey(symbExprTreeNode)) {
206        // undo node change
207        parent.RemoveSubtree(indexOfSubtree);
208        var originalNode = changedNodes[symbExprTreeNode];
209        parent.InsertSubtree(indexOfSubtree, originalNode);
210        changedNodes.Remove(symbExprTreeNode);
211      } else if (foldedNodes.ContainsKey(symbExprTreeNode)) {
212        // undo node folding
213        SwitchNodeWithReplacementNode(parent, indexOfSubtree);
214      }
215      UpdateModel(tree);
216    }
217
218    private void SwitchNodeWithReplacementNode(ISymbolicExpressionTreeNode parent, int subTreeIndex) {
219      ISymbolicExpressionTreeNode subTree = parent.GetSubtree(subTreeIndex);
220      if (foldedNodes.ContainsKey(subTree)) {
221        parent.RemoveSubtree(subTreeIndex);
222        var replacementNode = foldedNodes[subTree];
223        parent.InsertSubtree(subTreeIndex, replacementNode);
224        // exchange key and value
225        foldedNodes.Remove(subTree);
226        foldedNodes.Add(replacementNode, subTree);
227      }
228    }
229
230    private void PaintNodeImpacts() {
231      var impacts = nodeImpacts.Values;
232      double max = impacts.Max();
233      double min = impacts.Min();
234      foreach (ISymbolicExpressionTreeNode treeNode in Content.Model.SymbolicExpressionTree.IterateNodesPostfix()) {
235        VisualTreeNode<ISymbolicExpressionTreeNode> visualTree = treeChart.GetVisualSymbolicExpressionTreeNode(treeNode);
236
237        if (!(treeNode is ConstantTreeNode) && nodeImpacts.ContainsKey(treeNode)) {
238          visualTree.ToolTip = visualTree.Content.ToString();
239          double impact = nodeImpacts[treeNode];
240
241          // impact = 0 if no change
242          // impact < 0 if new solution is better
243          // impact > 0 if new solution is worse
244          if (impact < 0.0) {
245            // min is guaranteed to be < 0
246            visualTree.FillColor = Color.FromArgb((int)(impact / min * 255), Color.Red);
247          } else if (impact.IsAlmost(0.0)) {
248            visualTree.FillColor = Color.White;
249          } else {
250            // max is guaranteed to be > 0
251            visualTree.FillColor = Color.FromArgb((int)(impact / max * 255), Color.Green);
252          }
253          visualTree.ToolTip += Environment.NewLine + "Node impact: " + impact;
254          var constantReplacementNode = foldedNodes[treeNode] as ConstantTreeNode;
255          if (constantReplacementNode != null) {
256            visualTree.ToolTip += Environment.NewLine + "Replacement value: " + constantReplacementNode.Value;
257          }
258        }
259        if (visualTree != null)
260          if (changedNodes.ContainsKey(treeNode)) {
261            visualTree.LineColor = Color.DodgerBlue;
262          } else if (treeNode is ConstantTreeNode && foldedNodes.ContainsKey(treeNode)) {
263            visualTree.LineColor = Color.DarkOrange;
264          }
265      }
266      treeChart.RepaintNodes();
267    }
268
269    private void btnSimplify_Click(object sender, EventArgs e) {
270      var simplifier = new SymbolicDataAnalysisExpressionTreeSimplifier();
271      var simplifiedExpressionTree = simplifier.Simplify(Content.Model.SymbolicExpressionTree);
272      UpdateModel(simplifiedExpressionTree);
273    }
274
275    protected abstract void btnOptimizeConstants_Click(object sender, EventArgs e);
276  }
277}
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