deba@1554: /* -*- C++ -*-
ladanyi@1636:  * demo/descriptor_map_demo.cc - Part of LEMON, a generic C++ optimization
ladanyi@1636:  * library
deba@1554:  *
deba@1554:  * Copyright (C) 2005 Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
deba@1554:  * (Egervary Research Group on Combinatorial Optimization, EGRES).
deba@1554:  *
deba@1554:  * Permission to use, modify and distribute this software is granted
deba@1554:  * provided that this copyright notice appears in all copies. For
deba@1554:  * precise terms see the accompanying LICENSE file.
deba@1554:  *
deba@1554:  * This software is provided "AS IS" with no warranty of any kind,
deba@1554:  * express or implied, and with no claim as to its suitability for any
deba@1554:  * purpose.
deba@1554:  *
deba@1554:  */
deba@1554: 
deba@1553: #include <lemon/list_graph.h>
deba@1553: #include <lemon/graph_utils.h>
deba@1554: #include <lemon/graph_writer.h>
deba@1553: #include <lemon/xy.h>
deba@1554: #include <lemon/graph_to_eps.h>
deba@1553: 
deba@1554: #include <iostream>
deba@1553: 
deba@1553: #include <cstdlib>
deba@1553: #include <cmath>
deba@1553: #include <ctime>
deba@1553: 
deba@1553: using namespace lemon;
deba@1553: 
deba@1553: // Special map type
deba@1553: // It gives back a position for each node. The position of the nodes 
deba@1553: // are on the circle with the given center and radius.
deba@1553: //
deba@1553: // Because we use the descriptor map it will hold the proprty described above
deba@1553: // even if a node added or deleted. 
deba@1553: template <typename Graph>
deba@1553: class CircleMap {
deba@1553: public:
deba@1553: 
deba@1553:   typedef xy<double> Value;
deba@1553:   typedef typename Graph::Node Key;
deba@1553: 
deba@1553:   CircleMap(const Graph& _graph, 
deba@1553: 	    const Value& _center = Value(0.0, 0.0), 
deba@1553: 	    double _radius = 1.0) 
deba@1553:     : descriptor(_graph), center(_center), radius(_radius) {}
deba@1553: 
deba@1553:   Value operator[](const Key& key) const {
deba@1553:     double angle = descriptor[key] * 2 * M_PI 
deba@1553:       / (double)descriptor.inverse().size();
deba@1553:     double x = std::cos(angle) * radius + center.x;
deba@1553:     double y = std::sin(angle) * radius + center.y;
deba@1553:     return Value(x, y);
deba@1553:   }
deba@1553: 
deba@1553: private:
deba@1553:   
deba@1553:   DescriptorMap<Graph, typename Graph::Node> descriptor;
deba@1553:   Value center;
deba@1553:   double radius;
deba@1553: };
deba@1553: 
deba@1553: int main() {
deba@1553:   std::srand(std::time(0));
deba@1553:   typedef ListGraph Graph;
deba@1553:   typedef Graph::Node Node;
deba@1553:   typedef Graph::Edge Edge;
deba@1553:   
deba@1553:   // Generating a graph
deba@1554: 
deba@1554:   std::cout << "Generating graph: " << std::endl;
deba@1554: 
deba@1553:   Graph graph;
deba@1553:   
deba@1553:   const int NODE = 16;
deba@1553:   for (int i = 0; i < NODE; ++i) {
deba@1553:     graph.addNode();
deba@1553:   } 
deba@1553: 
deba@1553:   // Creating descriptor map and inverse
deba@1553:   DescriptorMap<Graph, Node> nodeDesc(graph);
deba@1553:   DescriptorMap<Graph, Node>::InverseMap nodeInv(nodeDesc);
deba@1553: 
deba@1553:   // Adding edges
deba@1553:   // The descriptor map always maps an integer value for each node.
deba@1553:   // The range of the values is always [0..n - 1] where n is the
deba@1553:   // number of the nodes of the graph. The inverse map gives back the
deba@1553:   // the node by its descriptor value. 
deba@1553:   //
deba@1553:   // The inversemap cannot works without its DescriptorMap because
deba@1553:   // it holds reference to it. 
alpar@1556:   const int EDGE = (int)(NODE * std::log(double(NODE)));
deba@1553:   for (int i = 0; i < EDGE; ++i) {
deba@1553:     int si = (int)(std::rand() / (RAND_MAX + 1.0) * NODE);
deba@1553:     int ti = (int)(std::rand() / (RAND_MAX + 1.0) * NODE);
deba@1553:       
deba@1553:     graph.addEdge(nodeInv[si], nodeInv[ti]);
deba@1553:   }
deba@1553: 
deba@1554:   GraphWriter<Graph>(std::cout, graph).run();
deba@1554: 
deba@1554:   std::cout << std::endl;
deba@1554:   std::cout << "Postscript file: descriptor_map_demo.eps" << std::endl;
deba@1554: 
deba@1553:   // Make postscript from the graph.
deba@1553:     
deba@1553:   CircleMap<Graph> coords(graph, xy<double>(0.0, 0.0), 10.0);
deba@1553:     
deba@1553:   graphToEps(graph,"descriptor_map_demo.eps").scaleToA4().
deba@1553:     title("Generated graph").
deba@1553:     copyright("(C) 2005 LEMON Project").
deba@1553:     coords(coords).
deba@1553:     nodeScale(1.0).
deba@1553:     enableParallel().parEdgeDist(1).
deba@1553:     drawArrows().arrowWidth(1).arrowLength(1).
deba@1553:     run();
deba@1553:  
deba@1553:   return 0;
deba@1553: }