tools/lgf-gen.cc
author alpar
Tue, 13 Mar 2007 16:32:35 +0000
changeset 2409 fe0a8fe16271
parent 2391 14a343be7a5a
child 2410 fe46b61da4e3
permissions -rw-r--r--
Minimum mean cycle algorithm contributed by Peter Kovacs.
     1 /* -*- C++ -*-
     2  *
     3  * This file is a part of LEMON, a generic C++ optimization library
     4  *
     5  * Copyright (C) 2003-2007
     6  * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
     7  * (Egervary Research Group on Combinatorial Optimization, EGRES).
     8  *
     9  * Permission to use, modify and distribute this software is granted
    10  * provided that this copyright notice appears in all copies. For
    11  * precise terms see the accompanying LICENSE file.
    12  *
    13  * This software is provided "AS IS" with no warranty of any kind,
    14  * express or implied, and with no claim as to its suitability for any
    15  * purpose.
    16  *
    17  */
    18 
    19 #include <lemon/list_graph.h>
    20 #include <lemon/graph_utils.h>
    21 #include <lemon/random.h>
    22 #include <lemon/dim2.h>
    23 #include <lemon/bfs.h>
    24 #include <lemon/counter.h>
    25 #include <lemon/suurballe.h>
    26 #include <lemon/graph_to_eps.h>
    27 #include <lemon/graph_writer.h>
    28 #include <lemon/arg_parser.h>
    29 #include <cmath>
    30 #include <algorithm>
    31 #include <lemon/unionfind.h>
    32 #include <lemon/time_measure.h>
    33 
    34 using namespace lemon;
    35 
    36 typedef dim2::Point<double> Point;
    37 
    38 UGRAPH_TYPEDEFS(ListUGraph);
    39 
    40 bool progress=true;
    41 
    42 int N;
    43 // int girth;
    44 
    45 ListUGraph g;
    46 
    47 std::vector<Node> nodes;
    48 ListUGraph::NodeMap<Point> coords(g);
    49 
    50 int tsp_impr_num=0;
    51 
    52 const double EPSILON=1e-8; 
    53 bool tsp_improve(Node u, Node v)
    54 {
    55   double luv=std::sqrt((coords[v]-coords[u]).normSquare());
    56   Node u2=u;
    57   Node v2=v;
    58   do {
    59     Node n;
    60     for(IncEdgeIt e(g,v2);(n=g.runningNode(e))==u2;++e);
    61     u2=v2;
    62     v2=n;
    63     if(luv+std::sqrt((coords[v2]-coords[u2]).normSquare())-EPSILON>
    64        std::sqrt((coords[u]-coords[u2]).normSquare())+
    65        std::sqrt((coords[v]-coords[v2]).normSquare()))
    66       {
    67  	g.erase(findUEdge(g,u,v));
    68  	g.erase(findUEdge(g,u2,v2));
    69 	g.addEdge(u2,u);
    70 	g.addEdge(v,v2);
    71 	tsp_impr_num++;
    72 	return true;
    73       }
    74   } while(v2!=u);
    75   return false;
    76 }
    77 
    78 bool tsp_improve(Node u)
    79 {
    80   for(IncEdgeIt e(g,u);e!=INVALID;++e)
    81     if(tsp_improve(u,g.runningNode(e))) return true;
    82   return false;
    83 }
    84 
    85 void tsp_improve()
    86 {
    87   bool b;
    88   do {
    89     b=false;
    90     for(NodeIt n(g);n!=INVALID;++n)
    91       if(tsp_improve(n)) b=true;
    92   } while(b);
    93 }
    94 
    95 void tsp()
    96 {
    97   for(int i=0;i<N;i++) g.addEdge(nodes[i],nodes[(i+1)%N]);
    98   tsp_improve();
    99 }
   100 
   101 class Line
   102 {
   103 public:
   104   Point a;
   105   Point b;
   106   Line(Point _a,Point _b) :a(_a),b(_b) {}
   107   Line(Node _a,Node _b) : a(coords[_a]),b(coords[_b]) {}
   108   Line(const Edge &e) : a(coords[g.source(e)]),b(coords[g.target(e)]) {}
   109   Line(const UEdge &e) : a(coords[g.source(e)]),b(coords[g.target(e)]) {}
   110 };
   111   
   112 inline std::ostream& operator<<(std::ostream &os, const Line &l)
   113 {
   114   os << l.a << "->" << l.b;
   115   return os;
   116 }
   117 
   118 bool cross(Line a, Line b) 
   119 {
   120   Point ao=rot90(a.b-a.a);
   121   Point bo=rot90(b.b-b.a);
   122   return (ao*(b.a-a.a))*(ao*(b.b-a.a))<0 &&
   123     (bo*(a.a-b.a))*(bo*(a.b-b.a))<0;
   124 }
   125 
   126 struct Pedge
   127 {
   128   Node a;
   129   Node b;
   130   double len;
   131 };
   132 
   133 bool pedgeLess(Pedge a,Pedge b)
   134 {
   135   return a.len<b.len;
   136 }
   137 
   138 std::vector<UEdge> edges;
   139 
   140 void triangle()
   141 {
   142   Counter cnt("Number of edges added: ");
   143   std::vector<Pedge> pedges;
   144   for(NodeIt n(g);n!=INVALID;++n) 
   145     for(NodeIt m=++(NodeIt(n));m!=INVALID;++m)
   146       {
   147 	Pedge p;
   148 	p.a=n;
   149 	p.b=m;
   150 	p.len=(coords[m]-coords[n]).normSquare();
   151 	pedges.push_back(p);
   152       }
   153   std::sort(pedges.begin(),pedges.end(),pedgeLess);
   154   for(std::vector<Pedge>::iterator pi=pedges.begin();pi!=pedges.end();++pi)
   155     {
   156       Line li(pi->a,pi->b);
   157       UEdgeIt e(g);
   158       for(;e!=INVALID && !cross(e,li);++e) ;
   159       UEdge ne;
   160       if(e==INVALID) {
   161 	ne=g.addEdge(pi->a,pi->b);
   162 	edges.push_back(ne);
   163 	cnt++;
   164       }
   165     }
   166 }
   167 
   168 void sparse(int d) 
   169 {
   170   Counter cnt("Number of edges removed: ");
   171   Bfs<ListUGraph> bfs(g);
   172   for(std::vector<UEdge>::reverse_iterator ei=edges.rbegin();
   173       ei!=edges.rend();++ei)
   174     {
   175       Node a=g.source(*ei);
   176       Node b=g.target(*ei);
   177       g.erase(*ei);
   178       bfs.run(a,b);
   179       if(bfs.predEdge(b)==INVALID || bfs.dist(b)>d)
   180 	g.addEdge(a,b);
   181       else cnt++;
   182     }
   183 }
   184 
   185 void sparse2(int d) 
   186 {
   187   Counter cnt("Number of edges removed: ");
   188   for(std::vector<UEdge>::reverse_iterator ei=edges.rbegin();
   189       ei!=edges.rend();++ei)
   190     {
   191       Node a=g.source(*ei);
   192       Node b=g.target(*ei);
   193       g.erase(*ei);
   194       ConstMap<Edge,int> cegy(1);
   195       Suurballe<ListUGraph,ConstMap<Edge,int> > sur(g,cegy,a,b);
   196       int k=sur.run(2);
   197       if(k<2 || sur.totalLength()>d)
   198 	g.addEdge(a,b);
   199       else cnt++;
   200 //       else std::cout << "Remove edge " << g.id(a) << "-" << g.id(b) << '\n';
   201     }
   202 }
   203 
   204 void sparseTriangle(int d)
   205 {
   206   Counter cnt("Number of edges added: ");
   207   std::vector<Pedge> pedges;
   208   for(NodeIt n(g);n!=INVALID;++n) 
   209     for(NodeIt m=++(NodeIt(n));m!=INVALID;++m)
   210       {
   211 	Pedge p;
   212 	p.a=n;
   213 	p.b=m;
   214 	p.len=(coords[m]-coords[n]).normSquare();
   215 	pedges.push_back(p);
   216       }
   217   std::sort(pedges.begin(),pedges.end(),pedgeLess);
   218   for(std::vector<Pedge>::iterator pi=pedges.begin();pi!=pedges.end();++pi)
   219     {
   220       Line li(pi->a,pi->b);
   221       UEdgeIt e(g);
   222       for(;e!=INVALID && !cross(e,li);++e) ;
   223       UEdge ne;
   224       if(e==INVALID) {
   225 	ConstMap<Edge,int> cegy(1);
   226 	Suurballe<ListUGraph,ConstMap<Edge,int> >
   227 	  sur(g,cegy,pi->a,pi->b);
   228 	int k=sur.run(2);
   229 	if(k<2 || sur.totalLength()>d)
   230 	  {
   231 	    ne=g.addEdge(pi->a,pi->b);
   232 	    edges.push_back(ne);
   233 	    cnt++;
   234 	  }
   235       }
   236     }
   237 }
   238 
   239 void minTree() {
   240   int en=0;
   241   int pr=0;
   242   std::vector<Pedge> pedges;
   243   Timer T;
   244   std::cout << T.realTime() << "s: Setting up the edges...\n";
   245   for(NodeIt n(g);n!=INVALID;++n) 
   246     {
   247       for(NodeIt m=++(NodeIt(n));m!=INVALID;++m)
   248 	{
   249 	  Pedge p;
   250 	  p.a=n;
   251 	  p.b=m;
   252 	  p.len=(coords[m]-coords[n]).normSquare();
   253 	  pedges.push_back(p);
   254 	}
   255       en++;
   256       if(progress && en>=pr*double(N)/100) 
   257 	{
   258 	  std::cout << pr << "%  \r" << std::flush;
   259 	  pr++;
   260 	}
   261     }
   262   std::cout << T.realTime() << "s: Sorting the edges...\n";
   263   std::sort(pedges.begin(),pedges.end(),pedgeLess);
   264   std::cout << T.realTime() << "s: Creating the tree...\n";
   265   ListUGraph::NodeMap<int> comp(g);
   266   UnionFind<ListUGraph::NodeMap<int> > uf(comp);
   267   for (NodeIt it(g); it != INVALID; ++it)
   268     uf.insert(it);  
   269   for(std::vector<Pedge>::iterator pi=pedges.begin();pi!=pedges.end();++pi)
   270     {
   271       if ( uf.join(pi->a,pi->b) ) {
   272 	g.addEdge(pi->a,pi->b);
   273 	if(en>=N-1)
   274 	  break;
   275       }
   276     }
   277   std::cout << T.realTime() << "s: Done\n";
   278 }
   279 
   280 
   281 
   282 int main(int argc,char **argv) 
   283 {
   284   ArgParser ap(argc,argv);
   285 
   286 //   bool eps;
   287   bool disc_d, square_d, gauss_d;
   288 //   bool tsp_a,two_a,tree_a;
   289   int num_of_cities=1;
   290   double area=1;
   291   N=100;
   292 //   girth=10;
   293   std::string ndist("disc");
   294   ap.refOption("n", "Number of nodes (default is 100)", N)
   295     .intOption("g", "Girth parameter (default is 10)", 10)
   296     .refOption("cities", "Number of cities (default is 1)", num_of_cities)
   297     .refOption("area", "Full relative area of the cities (default is 1)", area)
   298     .refOption("disc", "Nodes are evenly distributed on a unit disc (default)",disc_d)
   299     .optionGroup("dist", "disc")
   300     .refOption("square", "Nodes are evenly distributed on a unit square", square_d)
   301     .optionGroup("dist", "square")
   302     .refOption("gauss",
   303 	    "Nodes are located according to a two-dim gauss distribution",
   304 	    gauss_d)
   305     .optionGroup("dist", "gauss")
   306 //     .mandatoryGroup("dist")
   307     .onlyOneGroup("dist")
   308     .boolOption("eps", "Also generate .eps output (prefix.eps)")
   309     .boolOption("2con", "Create a two connected planar graph")
   310     .optionGroup("alg","2con")
   311     .boolOption("tree", "Create a min. cost spanning tree")
   312     .optionGroup("alg","tree")
   313     .boolOption("tsp", "Create a TSP tour")
   314     .optionGroup("alg","tsp")
   315     .onlyOneGroup("alg")
   316     .other("[prefix]","Prefix of the output files. Default is 'lgf-gen-out'")
   317     .run();
   318   
   319   std::string prefix;
   320   switch(ap.files().size()) 
   321     {
   322     case 0:
   323       prefix="lgf-gen-out";
   324       break;
   325     case 1:
   326       prefix=ap.files()[0];
   327       break;
   328     default:
   329       std::cerr << "\nAt most one prefix can be given\n\n";
   330       exit(1);
   331     }
   332   
   333   double sum_sizes=0;
   334   std::vector<double> sizes;
   335   std::vector<double> cum_sizes;
   336   for(int s=0;s<num_of_cities;s++) 
   337     {
   338       // 	sum_sizes+=rnd.exponential();
   339       double d=rnd();
   340       sum_sizes+=d;
   341       sizes.push_back(d);
   342       cum_sizes.push_back(sum_sizes);
   343     }
   344   int i=0;
   345   for(int s=0;s<num_of_cities;s++) 
   346     {
   347       Point center=(num_of_cities==1?Point(0,0):rnd.disc());
   348       if(gauss_d)
   349 	for(;i<N*(cum_sizes[s]/sum_sizes);i++) {
   350 	  Node n=g.addNode();
   351 	  nodes.push_back(n);
   352 	  coords[n]=center+rnd.gauss2()*area*
   353 	    std::sqrt(sizes[s]/sum_sizes);
   354 	}
   355       else if(square_d)
   356 	for(;i<N*(cum_sizes[s]/sum_sizes);i++) {
   357 	  Node n=g.addNode();
   358 	  nodes.push_back(n);
   359 	  coords[n]=center+Point(rnd()*2-1,rnd()*2-1)*area*
   360 	    std::sqrt(sizes[s]/sum_sizes);
   361 	}
   362       else if(disc_d || true)
   363 	for(;i<N*(cum_sizes[s]/sum_sizes);i++) {
   364 	  Node n=g.addNode();
   365 	  nodes.push_back(n);
   366 	  coords[n]=center+rnd.disc()*area*
   367 	    std::sqrt(sizes[s]/sum_sizes);
   368 	}
   369     }
   370   
   371   if(ap["tsp"]) {
   372     tsp();
   373     std::cout << "#2-opt improvements: " << tsp_impr_num << std::endl;
   374   }
   375   else if(ap["2con"]) {
   376     std::cout << "Make triangles\n";
   377     //   triangle();
   378     sparseTriangle(ap["g"]);
   379     std::cout << "Make it sparser\n";
   380     sparse2(ap["g"]);
   381   }
   382   else if(ap["tree"]) {
   383     minTree();
   384   }
   385   
   386 
   387   std::cout << "Number of nodes    : " << countNodes(g) << std::endl;
   388   std::cout << "Number of edges    : " << countUEdges(g) << std::endl;
   389   double tlen=0;
   390   for(UEdgeIt e(g);e!=INVALID;++e)
   391     tlen+=sqrt((coords[g.source(e)]-coords[g.target(e)]).normSquare());
   392   std::cout << "Total edge length  : " << tlen << std::endl;
   393   if(ap["eps"])
   394     graphToEps(g,prefix+".eps").
   395       scale(600).nodeScale(.2).edgeWidthScale(.001).preScale(false).
   396       coords(coords).run();
   397 
   398   UGraphWriter<ListUGraph>(prefix+".lgf",g).
   399     writeNodeMap("coordinates_x",scaleMap(xMap(coords),600)).
   400     writeNodeMap("coordinates_y",scaleMap(yMap(coords),600)).
   401     run();
   402 }
   403