1  #region License Information


2  /* HeuristicLab


3  * Copyright (C) 20022016 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 


22  using System;


23  using System.Collections.Generic;


24 


25  namespace HeuristicLab.IGraph.Wrappers {


26  public sealed class Graph : IDisposable {


27  private igraph_t graph;


28  internal igraph_t NativeInstance { get { return graph; } }


29 


30  public int Vertices { get { return graph.n; } }


31  public bool IsDirected { get { return graph.directed; } }


32 


33  public Graph() : this(0) { }


34  public Graph(int vertices) : this(vertices, false) { }


35  public Graph(int vertices, bool directed) {


36  graph = new igraph_t();


37  DllImporter.igraph_empty(graph, vertices, directed);


38  }


39  public Graph(int vertices, IEnumerable<Tuple<int, int>> edges) : this(vertices, edges, false) { }


40  public Graph(int vertices, IEnumerable<Tuple<int, int>> edges, bool directed) {


41  graph = new igraph_t();


42  DllImporter.igraph_empty(graph, vertices, directed);


43  foreach (var e in edges)


44  DllImporter.igraph_add_edge(graph, e.Item1, e.Item2);


45  }


46  ~Graph() {


47  DllImporter.igraph_destroy(graph);


48  }


49 


50  public void Dispose() {


51  if (graph == null) return;


52  DllImporter.igraph_destroy(graph);


53  graph = null;


54  GC.SuppressFinalize(this);


55  }


56 


57  public void SetSeed(uint seed) {


58  DllImporter.igraph_rng_seed(seed);


59  }


60 


61  public int RandomInteger(int inclLower, int inclUpper) {


62  return DllImporter.igraph_rng_get_integer(inclLower, inclUpper);


63  }


64 


65  public double Density() {


66  double density;


67  DllImporter.igraph_density(graph, out density, false);


68  return density;


69  }


70 


71  public Vector PageRank(double damping = 0.85, Vector weights = null) {


72  var vec = new Vector(Vertices);


73  var all = new igraph_vs_t();


74  DllImporter.igraph_vs_all(ref all);


75  try {


76  double eigenv = 0;


77  DllImporter.igraph_pagerank(graph, igraph_pagerank_algo_t.IGRAPH_PAGERANK_ALGO_PRPACK, vec.NativeInstance, out eigenv, all, IsDirected, damping, weights != null ? weights.NativeInstance : null);


78  } finally {


79  DllImporter.igraph_vs_destroy(ref all);


80  }


81  return vec;


82  }


83 


84  public Matrix LayoutWithFruchtermanReingold(Matrix initialCoords = null) {


85  return LayoutWithFruchtermanReingold(500, Math.Sqrt(Vertices), initialCoords);


86  }


87  public Matrix LayoutWithFruchtermanReingold(int niter, double startTemp, Matrix initialCoords = null) {


88  if (initialCoords != null && (initialCoords.Rows != Vertices  initialCoords.Columns != 2))


89  throw new ArgumentException("Initial coordinate matrix does not contain the required number of rows and columns.", "initialCoords");


90  var coords = initialCoords != null ? new Matrix(initialCoords) : new Matrix(Vertices, 2);


91  DllImporter.igraph_layout_fruchterman_reingold(graph, coords.NativeInstance, initialCoords != null, niter, startTemp, igraph_layout_grid_t.IGRAPH_LAYOUT_AUTOGRID, null, null, null, null, null);


92  return coords;


93  }


94 


95  public Matrix LayoutWithKamadaKawai(Matrix initialCoords = null) {


96  return LayoutWithKamadaKawai(50 * Vertices, 0, Vertices, initialCoords);


97  }


98  public Matrix LayoutWithKamadaKawai(int maxiter, double epsilon, double kkconst, Matrix initialCoords = null) {


99  if (initialCoords != null && (initialCoords.Rows != Vertices  initialCoords.Columns != 2))


100  throw new ArgumentException("Initial coordinate matrix does not contain the required number of rows and columns.", "initialCoords");


101  var coords = initialCoords != null ? new Matrix(initialCoords) : new Matrix(Vertices, 2);


102  DllImporter.igraph_layout_kamada_kawai(graph, coords.NativeInstance, initialCoords != null, maxiter, epsilon, kkconst, null, null, null, null, null);


103  return coords;


104  }


105 


106  public Matrix LayoutWithDavidsonHarel(Matrix initialCoords = null) {


107  var density = Density();


108  return LayoutWithDavidsonHarel(10, Math.Max(10, (int)Math.Log(Vertices, 2)), 0.75, 1.0, 0.0, density / 10.0, 1.0  Math.Sqrt(density), 0.2 * (1  density), initialCoords);


109  }


110  public Matrix LayoutWithDavidsonHarel(int maxiter, int fineiter, double cool_fact, double weight_node_dist, double weight_border, double weight_edge_lengths, double weight_edge_crossings, double weight_node_edge_dist, Matrix initialCoords = null) {


111  if (initialCoords != null && (initialCoords.Rows != Vertices  initialCoords.Columns != 2))


112  throw new ArgumentException("Initial coordinate matrix does not contain the required number of rows and columns.", "initialCoords");


113  var coords = initialCoords != null ? new Matrix(initialCoords) : new Matrix(Vertices, 2);


114  DllImporter.igraph_layout_davidson_harel(graph, coords.NativeInstance, initialCoords != null, maxiter, fineiter, cool_fact, weight_node_dist, weight_border, weight_edge_lengths, weight_edge_crossings, weight_node_edge_dist);


115  return coords;


116  }


117 


118  /// <summary>


119  /// Use multidimensional scaling to layout vertices.


120  /// A distance matrix can be used to specify the distances between the vertices.


121  /// Otherwise the distances will be calculated by shortestpathlength.


122  /// </summary>


123  /// <remarks>


124  /// For disconnected graphs, dimension must be 2.


125  /// </remarks>


126  /// <param name="dist">The distance matrix to layout the vertices.</param>


127  /// <param name="dim">How many dimensions should be used.</param>


128  /// <returns>The coordinates matrix of the aligned vertices.</returns>


129  public Matrix LayoutWithMds(Matrix dist = null, int dim = 2) {


130  var coords = new Matrix(Vertices, dim);


131  DllImporter.igraph_layout_mds(graph, coords.NativeInstance, dist != null ? dist.NativeInstance : null, dim);


132  return coords;


133  }


134 


135  public void BreadthFirstWalk(BreadthFirstHandler handler, int root, DirectedWalkMode mode, bool includeUnreachableFromRoot = false, object tag = null) {


136  igraph_bfshandler_t wrapper = (t, vid, pred, succ, rank, dist, extra) => handler != null && handler(this, vid, pred, succ, rank, dist, tag);


137  DllImporter.igraph_bfs(graph, root, null, (igraph_neimode_t)mode, includeUnreachableFromRoot, null, null, null, null, null, null, null, wrapper, tag);


138  }


139 


140  public void DepthFirstWalk(DepthFirstHandler inHandler, DepthFirstHandler outHandler, int root, DirectedWalkMode mode, bool includeUnreachableFromRoot = false, object tag = null) {


141  igraph_dfshandler_t inWrapper = (t, vid, dist, extra) => inHandler != null && inHandler(this, vid, dist, tag);


142  igraph_dfshandler_t outWrapper = (t, vid, dist, extra) => outHandler != null && outHandler(this, vid, dist, tag);


143  DllImporter.igraph_dfs(graph, root, (igraph_neimode_t)mode, includeUnreachableFromRoot, null, null, null, null, inWrapper, outWrapper, tag);


144  }


145  }


146  }

