1  #region License Information


2  /* HeuristicLab


3  * Copyright (C) 20022018 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 double Density() {


62  double density;


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


64  return density;


65  }


66 


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


68  var vec = new Vector(Vertices);


69  var all = new igraph_vs_t();


70  DllImporter.igraph_vs_all(ref all);


71  try {


72  double eigenv = 0;


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


74  } finally {


75  DllImporter.igraph_vs_destroy(ref all);


76  }


77  return vec;


78  }


79 


80  public Matrix LayoutWithFruchtermanReingold(Matrix initialCoords = null) {


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


82  }


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


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


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


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


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


88  return coords;


89  }


90 


91  public Matrix LayoutWithKamadaKawai(Matrix initialCoords = null) {


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


93  }


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


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


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


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


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


99  return coords;


100  }


101 


102  public Matrix LayoutWithDavidsonHarel(Matrix initialCoords = null) {


103  var density = Density();


104  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);


105  }


106  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) {


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


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


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


110  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);


111  return coords;


112  }


113 


114  /// <summary>


115  /// Use multidimensional scaling to layout vertices.


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


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


118  /// </summary>


119  /// <remarks>


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


121  /// </remarks>


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


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


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


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


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


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


128  return coords;


129  }


130 


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


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


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


134  }


135 


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


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


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


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


140  }


141  }


142  }

