source: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Encodings.SymbolicExpressionTreeEncoding/3.4/Formatters/SymbolicExpressionTreeLatexFormatter.cs @ 10459

using System;
using System.Collections.Generic;
using System.Globalization;
using System.Linq;
using System.Text;
using HeuristicLab.Common;
using HeuristicLab.Core;

namespace HeuristicLab.Encodings.SymbolicExpressionTreeEncoding {
  [Item("LaTeX/PDF Formatter", "Formatter for symbolic expression trees for use with latex.")]
  public class SymbolicExpressionTreeLatexFormatter : NamedItem, ISymbolicExpressionTreeStringFormatter {
    private readonly static Dictionary<string, string> SymbolNamesMap = new Dictionary<string, string>
    {
      {"ProgramRootSymbol", "Prog"},
      {"StartSymbol","RPB"},
      {"Addition", "$+$"},
      {"Subtraction", "$-$"},
      {"Multiplication", "$\\times$"},
      {"Division", "$\\div$"},
      {"Logarithm", "$\\log$"},
      {"Exponential", "$\\exp$"}
    };
    private readonly ReingoldTilfordLayoutEngine<ISymbolicExpressionTreeNode> layoutEngine;
    private readonly SymbolicExpressionTreeLayoutAdapter layoutAdapter;

    public SymbolicExpressionTreeLatexFormatter() {
      layoutEngine = new ReingoldTilfordLayoutEngine<ISymbolicExpressionTreeNode>();
      layoutAdapter = new SymbolicExpressionTreeLayoutAdapter();
    }

    protected SymbolicExpressionTreeLatexFormatter(SymbolicExpressionTreeLatexFormatter original, Cloner cloner)
      : base(original, cloner) {
      layoutEngine = new ReingoldTilfordLayoutEngine<ISymbolicExpressionTreeNode>();
      layoutAdapter = new SymbolicExpressionTreeLayoutAdapter();
    }

    public override IDeepCloneable Clone(Cloner cloner) {
      return new SymbolicExpressionTreeLatexFormatter(this, cloner);
    }

    public string Format(ISymbolicExpressionTree symbolicExpressionTree) {
      var layoutNodes = layoutAdapter.Convert(symbolicExpressionTree).ToList();
      layoutEngine.Reset();
      layoutEngine.Root = layoutNodes[0];
      foreach (var ln in layoutNodes)
        layoutEngine.AddNode(ln.Content, ln);
      layoutEngine.CalculateLayout();
      var nodeCoordinates = layoutEngine.GetNodeCoordinates();
      var sb = new StringBuilder();
      var nl = Environment.NewLine;
      sb.Append("\\documentclass[class=minimal,border=0pt]{standalone}" + nl +
                "\\usepackage{tikz}" + nl +
                "\\begin{document}" + nl +
                "\\begin{tikzpicture}" + nl +
                "\\def\\ws{1}" + nl +
                "\\def\\hs{0.7}" + nl);

      const double ws = 1.0, hs = 0.7; // some scaling factors useful for fine-tuning document appearance before latex compilation
      var nodes = symbolicExpressionTree.IterateNodesBreadth().ToList();
      var nodeIndices = new Dictionary<ISymbolicExpressionTreeNode, int>();
      for (int i = 0; i < nodes.Count; ++i) {
        var node = nodes[i];
        nodeIndices.Add(node, i);
        var symbolName = node.Symbol.Name;
        var nodeName = SymbolNamesMap.ContainsKey(symbolName) ? SymbolNamesMap[symbolName] : symbolName;
        var coord = nodeCoordinates[node];

        sb.AppendLine(string.Format(CultureInfo.InvariantCulture, "\\node ({0}) at (\\ws*{1},\\hs*{2}) {{{3}}};", i, ws * coord.X, -hs * coord.Y, EscapeLatexString(nodeName)));
      }

      for (int i = 0; i < nodes.Count; ++i) {
        foreach (var s in nodes[i].Subtrees) {
          sb.AppendLine(string.Format(CultureInfo.InvariantCulture, "\\draw ({0}) -- ({1});", i, nodeIndices[s]));
        }
      }

      sb.AppendLine("\\end{tikzpicture}" + nl + "\\end{document}" + nl);

      return sb.ToString();
    }

    private static string EscapeLatexString(string s) {
      return s.Replace("\\", "\\\\").Replace("{", "\\{").Replace("}", "\\}").Replace("_", "\\_");
    }
  }
}