1 | #include <lemon/list_graph.h> |
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2 | #include <lemon/graph_utils.h> |
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3 | #include <lemon/xy.h> |
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4 | |
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5 | #include <lemon/graph_to_eps.h> |
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6 | |
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7 | #include <cstdlib> |
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8 | #include <cmath> |
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9 | #include <ctime> |
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10 | |
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11 | using namespace lemon; |
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12 | |
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13 | // Special map type |
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14 | // It gives back a position for each node. The position of the nodes |
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15 | // are on the circle with the given center and radius. |
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16 | // |
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17 | // Because we use the descriptor map it will hold the proprty described above |
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18 | // even if a node added or deleted. |
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19 | template <typename Graph> |
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20 | class CircleMap { |
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21 | public: |
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22 | |
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23 | typedef xy<double> Value; |
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24 | typedef typename Graph::Node Key; |
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25 | |
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26 | CircleMap(const Graph& _graph, |
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27 | const Value& _center = Value(0.0, 0.0), |
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28 | double _radius = 1.0) |
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29 | : descriptor(_graph), center(_center), radius(_radius) {} |
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30 | |
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31 | Value operator[](const Key& key) const { |
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32 | double angle = descriptor[key] * 2 * M_PI |
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33 | / (double)descriptor.inverse().size(); |
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34 | double x = std::cos(angle) * radius + center.x; |
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35 | double y = std::sin(angle) * radius + center.y; |
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36 | return Value(x, y); |
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37 | } |
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38 | |
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39 | private: |
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40 | |
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41 | DescriptorMap<Graph, typename Graph::Node> descriptor; |
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42 | Value center; |
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43 | double radius; |
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44 | }; |
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45 | |
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46 | int main() { |
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47 | std::srand(std::time(0)); |
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48 | typedef ListGraph Graph; |
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49 | typedef Graph::Node Node; |
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50 | typedef Graph::Edge Edge; |
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51 | |
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52 | // Generating a graph |
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53 | |
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54 | Graph graph; |
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55 | |
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56 | const int NODE = 16; |
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57 | for (int i = 0; i < NODE; ++i) { |
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58 | graph.addNode(); |
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59 | } |
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60 | |
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61 | // Creating descriptor map and inverse |
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62 | DescriptorMap<Graph, Node> nodeDesc(graph); |
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63 | DescriptorMap<Graph, Node>::InverseMap nodeInv(nodeDesc); |
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64 | |
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65 | // Adding edges |
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66 | // The descriptor map always maps an integer value for each node. |
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67 | // The range of the values is always [0..n - 1] where n is the |
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68 | // number of the nodes of the graph. The inverse map gives back the |
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69 | // the node by its descriptor value. |
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70 | // |
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71 | // The inversemap cannot works without its DescriptorMap because |
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72 | // it holds reference to it. |
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73 | const int EDGE = (int)(NODE * std::log(NODE)); |
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74 | for (int i = 0; i < EDGE; ++i) { |
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75 | int si = (int)(std::rand() / (RAND_MAX + 1.0) * NODE); |
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76 | int ti = (int)(std::rand() / (RAND_MAX + 1.0) * NODE); |
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77 | |
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78 | graph.addEdge(nodeInv[si], nodeInv[ti]); |
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79 | } |
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80 | |
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81 | // Make postscript from the graph. |
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82 | |
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83 | CircleMap<Graph> coords(graph, xy<double>(0.0, 0.0), 10.0); |
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84 | |
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85 | graphToEps(graph,"descriptor_map_demo.eps").scaleToA4(). |
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86 | title("Generated graph"). |
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87 | copyright("(C) 2005 LEMON Project"). |
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88 | coords(coords). |
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89 | nodeScale(1.0). |
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90 | enableParallel().parEdgeDist(1). |
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91 | drawArrows().arrowWidth(1).arrowLength(1). |
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92 | run(); |
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93 | |
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94 | return 0; |
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95 | } |
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