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Differential D5594 Diff 18104 extern/quadriflow/3rd/lemon-1.3.1/tools/lgf-gen.cc

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extern/quadriflow/3rd/lemon-1.3.1/tools/lgf-gen.cc

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/* -*- mode: C++; indent-tabs-mode: nil; -*-
*
* This file is a part of LEMON, a generic C++ optimization library.
*
* Copyright (C) 2003-2009
* Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
* (Egervary Research Group on Combinatorial Optimization, EGRES).
*
* Permission to use, modify and distribute this software is granted
* provided that this copyright notice appears in all copies. For
* precise terms see the accompanying LICENSE file.
*
* This software is provided "AS IS" with no warranty of any kind,
* express or implied, and with no claim as to its suitability for any
* purpose.
*
*/
/// \ingroup tools
/// \file
/// \brief Special plane graph generator.
///
/// Graph generator application for various types of plane graphs.
///
/// See
/// \code
/// lgf-gen --help
/// \endcode
/// for more information on the usage.
#include <algorithm>
#include <set>
#include <ctime>
#include <lemon/list_graph.h>
#include <lemon/random.h>
#include <lemon/dim2.h>
#include <lemon/bfs.h>
#include <lemon/counter.h>
#include <lemon/suurballe.h>
#include <lemon/graph_to_eps.h>
#include <lemon/lgf_writer.h>
#include <lemon/arg_parser.h>
#include <lemon/euler.h>
#include <lemon/math.h>
#include <lemon/kruskal.h>
#include <lemon/time_measure.h>
using namespace lemon;
typedef dim2::Point<double> Point;
GRAPH_TYPEDEFS(ListGraph);
bool progress=true;
int N;
// int girth;
ListGraph g;
std::vector<Node> nodes;
ListGraph::NodeMap<Point> coords(g);
double totalLen(){
double tlen=0;
for(EdgeIt e(g);e!=INVALID;++e)
tlen+=std::sqrt((coords[g.v(e)]-coords[g.u(e)]).normSquare());
return tlen;
}
int tsp_impr_num=0;
const double EPSILON=1e-8;
bool tsp_improve(Node u, Node v)
{
double luv=std::sqrt((coords[v]-coords[u]).normSquare());
Node u2=u;
Node v2=v;
do {
Node n;
for(IncEdgeIt e(g,v2);(n=g.runningNode(e))==u2;++e) { }
u2=v2;
v2=n;
if(luv+std::sqrt((coords[v2]-coords[u2]).normSquare())-EPSILON>
std::sqrt((coords[u]-coords[u2]).normSquare())+
std::sqrt((coords[v]-coords[v2]).normSquare()))
{
g.erase(findEdge(g,u,v));
g.erase(findEdge(g,u2,v2));
g.addEdge(u2,u);
g.addEdge(v,v2);
tsp_impr_num++;
return true;
}
} while(v2!=u);
return false;
}
bool tsp_improve(Node u)
{
for(IncEdgeIt e(g,u);e!=INVALID;++e)
if(tsp_improve(u,g.runningNode(e))) return true;
return false;
}
void tsp_improve()
{
bool b;
do {
b=false;
for(NodeIt n(g);n!=INVALID;++n)
if(tsp_improve(n)) b=true;
} while(b);
}
void tsp()
{
for(int i=0;i<N;i++) g.addEdge(nodes[i],nodes[(i+1)%N]);
tsp_improve();
}
class Line
{
public:
Point a;
Point b;
Line(Point _a,Point _b) :a(_a),b(_b) {}
Line(Node _a,Node _b) : a(coords[_a]),b(coords[_b]) {}
Line(const Arc &e) : a(coords[g.source(e)]),b(coords[g.target(e)]) {}
Line(const Edge &e) : a(coords[g.u(e)]),b(coords[g.v(e)]) {}
};
inline std::ostream& operator<<(std::ostream &os, const Line &l)
{
os << l.a << "->" << l.b;
return os;
}
bool cross(Line a, Line b)
{
Point ao=rot90(a.b-a.a);
Point bo=rot90(b.b-b.a);
return (ao*(b.a-a.a))*(ao*(b.b-a.a))<0 &&
(bo*(a.a-b.a))*(bo*(a.b-b.a))<0;
}
struct Parc
{
Node a;
Node b;
double len;
};
bool pedgeLess(Parc a,Parc b)
{
return a.len<b.len;
}
std::vector<Edge> arcs;
namespace _delaunay_bits {
struct Part {
int prev, curr, next;
Part(int p, int c, int n) : prev(p), curr(c), next(n) {}
};
inline std::ostream& operator<<(std::ostream& os, const Part& part) {
os << '(' << part.prev << ',' << part.curr << ',' << part.next << ')';
return os;
}
inline double circle_point(const Point& p, const Point& q, const Point& r) {
double a = p.x * (q.y - r.y) + q.x * (r.y - p.y) + r.x * (p.y - q.y);
if (a == 0) return std::numeric_limits<double>::quiet_NaN();
double d = (p.x * p.x + p.y * p.y) * (q.y - r.y) +
(q.x * q.x + q.y * q.y) * (r.y - p.y) +
(r.x * r.x + r.y * r.y) * (p.y - q.y);
double e = (p.x * p.x + p.y * p.y) * (q.x - r.x) +
(q.x * q.x + q.y * q.y) * (r.x - p.x) +
(r.x * r.x + r.y * r.y) * (p.x - q.x);
double f = (p.x * p.x + p.y * p.y) * (q.x * r.y - r.x * q.y) +
(q.x * q.x + q.y * q.y) * (r.x * p.y - p.x * r.y) +
(r.x * r.x + r.y * r.y) * (p.x * q.y - q.x * p.y);
return d / (2 * a) + std::sqrt((d * d + e * e) / (4 * a * a) + f / a);
}
inline bool circle_form(const Point& p, const Point& q, const Point& r) {
return rot90(q - p) * (r - q) < 0.0;
}
inline double intersection(const Point& p, const Point& q, double sx) {
const double epsilon = 1e-8;
if (p.x == q.x) return (p.y + q.y) / 2.0;
if (sx < p.x + epsilon) return p.y;
if (sx < q.x + epsilon) return q.y;
double a = q.x - p.x;
double b = (q.x - sx) * p.y - (p.x - sx) * q.y;
double d = (q.x - sx) * (p.x - sx) * (p - q).normSquare();
return (b - std::sqrt(d)) / a;
}
struct YLess {
YLess(const std::vector<Point>& points, double& sweep)
: _points(points), _sweep(sweep) {}
bool operator()(const Part& l, const Part& r) const {
const double epsilon = 1e-8;
// std::cerr << l << " vs " << r << std::endl;
double lbx = l.prev != -1 ?
intersection(_points[l.prev], _points[l.curr], _sweep) :
- std::numeric_limits<double>::infinity();
double rbx = r.prev != -1 ?
intersection(_points[r.prev], _points[r.curr], _sweep) :
- std::numeric_limits<double>::infinity();
double lex = l.next != -1 ?
intersection(_points[l.curr], _points[l.next], _sweep) :
std::numeric_limits<double>::infinity();
double rex = r.next != -1 ?
intersection(_points[r.curr], _points[r.next], _sweep) :
std::numeric_limits<double>::infinity();
if (lbx > lex) std::swap(lbx, lex);
if (rbx > rex) std::swap(rbx, rex);
if (lex < epsilon + rex && lbx + epsilon < rex) return true;
if (rex < epsilon + lex && rbx + epsilon < lex) return false;
return lex < rex;
}
const std::vector<Point>& _points;
double& _sweep;
};
struct BeachIt;
typedef std::multimap<double, BeachIt*> SpikeHeap;
typedef std::multimap<Part, SpikeHeap::iterator, YLess> Beach;
struct BeachIt {
Beach::iterator it;
BeachIt(Beach::iterator iter) : it(iter) {}
};
}
inline void delaunay() {
Counter cnt("Number of arcs added: ");
using namespace _delaunay_bits;
typedef _delaunay_bits::Part Part;
typedef std::vector<std::pair<double, int> > SiteHeap;
std::vector<Point> points;
std::vector<Node> nodes;
for (NodeIt it(g); it != INVALID; ++it) {
nodes.push_back(it);
points.push_back(coords[it]);
}
SiteHeap siteheap(points.size());
double sweep;
for (int i = 0; i < int(siteheap.size()); ++i) {
siteheap[i] = std::make_pair(points[i].x, i);
}
std::sort(siteheap.begin(), siteheap.end());
sweep = siteheap.front().first;
YLess yless(points, sweep);
Beach beach(yless);
SpikeHeap spikeheap;
std::set<std::pair<int, int> > arcs;
int siteindex = 0;
{
SiteHeap front;
while (siteindex < int(siteheap.size()) &&
siteheap[0].first == siteheap[siteindex].first) {
front.push_back(std::make_pair(points[siteheap[siteindex].second].y,
siteheap[siteindex].second));
++siteindex;
}
std::sort(front.begin(), front.end());
for (int i = 0; i < int(front.size()); ++i) {
int prev = (i == 0 ? -1 : front[i - 1].second);
int curr = front[i].second;
int next = (i + 1 == int(front.size()) ? -1 : front[i + 1].second);
beach.insert(std::make_pair(Part(prev, curr, next),
spikeheap.end()));
}
}
while (siteindex < int(points.size()) || !spikeheap.empty()) {
SpikeHeap::iterator spit = spikeheap.begin();
if (siteindex < int(points.size()) &&
(spit == spikeheap.end() || siteheap[siteindex].first < spit->first)) {
int site = siteheap[siteindex].second;
sweep = siteheap[siteindex].first;
Beach::iterator bit = beach.upper_bound(Part(site, site, site));
if (bit->second != spikeheap.end()) {
delete bit->second->second;
spikeheap.erase(bit->second);
}
int prev = bit->first.prev;
int curr = bit->first.curr;
int next = bit->first.next;
beach.erase(bit);
SpikeHeap::iterator pit = spikeheap.end();
if (prev != -1 &&
circle_form(points[prev], points[curr], points[site])) {
double x = circle_point(points[prev], points[curr], points[site]);
pit = spikeheap.insert(std::make_pair(x, new BeachIt(beach.end())));
pit->second->it =
beach.insert(std::make_pair(Part(prev, curr, site), pit));
} else {
beach.insert(std::make_pair(Part(prev, curr, site), pit));
}
beach.insert(std::make_pair(Part(curr, site, curr), spikeheap.end()));
SpikeHeap::iterator nit = spikeheap.end();
if (next != -1 &&
circle_form(points[site], points[curr],points[next])) {
double x = circle_point(points[site], points[curr], points[next]);
nit = spikeheap.insert(std::make_pair(x, new BeachIt(beach.end())));
nit->second->it =
beach.insert(std::make_pair(Part(site, curr, next), nit));
} else {
beach.insert(std::make_pair(Part(site, curr, next), nit));
}
++siteindex;
} else {
sweep = spit->first;
Beach::iterator bit = spit->second->it;
int prev = bit->first.prev;
int curr = bit->first.curr;
int next = bit->first.next;
{
std::pair<int, int> arc;
arc = prev < curr ?
std::make_pair(prev, curr) : std::make_pair(curr, prev);
if (arcs.find(arc) == arcs.end()) {
arcs.insert(arc);
g.addEdge(nodes[prev], nodes[curr]);
++cnt;
}
arc = curr < next ?
std::make_pair(curr, next) : std::make_pair(next, curr);
if (arcs.find(arc) == arcs.end()) {
arcs.insert(arc);
g.addEdge(nodes[curr], nodes[next]);
++cnt;
}
}
Beach::iterator pbit = bit; --pbit;
int ppv = pbit->first.prev;
Beach::iterator nbit = bit; ++nbit;
int nnt = nbit->first.next;
if (bit->second != spikeheap.end())
{
delete bit->second->second;
spikeheap.erase(bit->second);
}
if (pbit->second != spikeheap.end())
{
delete pbit->second->second;
spikeheap.erase(pbit->second);
}
if (nbit->second != spikeheap.end())
{
delete nbit->second->second;
spikeheap.erase(nbit->second);
}
beach.erase(nbit);
beach.erase(bit);
beach.erase(pbit);
SpikeHeap::iterator pit = spikeheap.end();
if (ppv != -1 && ppv != next &&
circle_form(points[ppv], points[prev], points[next])) {
double x = circle_point(points[ppv], points[prev], points[next]);
if (x < sweep) x = sweep;
pit = spikeheap.insert(std::make_pair(x, new BeachIt(beach.end())));
pit->second->it =
beach.insert(std::make_pair(Part(ppv, prev, next), pit));
} else {
beach.insert(std::make_pair(Part(ppv, prev, next), pit));
}
SpikeHeap::iterator nit = spikeheap.end();
if (nnt != -1 && prev != nnt &&
circle_form(points[prev], points[next], points[nnt])) {
double x = circle_point(points[prev], points[next], points[nnt]);
if (x < sweep) x = sweep;
nit = spikeheap.insert(std::make_pair(x, new BeachIt(beach.end())));
nit->second->it =
beach.insert(std::make_pair(Part(prev, next, nnt), nit));
} else {
beach.insert(std::make_pair(Part(prev, next, nnt), nit));
}
}
}
for (Beach::iterator it = beach.begin(); it != beach.end(); ++it) {
int curr = it->first.curr;
int next = it->first.next;
if (next == -1) continue;
std::pair<int, int> arc;
arc = curr < next ?
std::make_pair(curr, next) : std::make_pair(next, curr);
if (arcs.find(arc) == arcs.end()) {
arcs.insert(arc);
g.addEdge(nodes[curr], nodes[next]);
++cnt;
}
}
}
void sparse(int d)
{
Counter cnt("Number of arcs removed: ");
Bfs<ListGraph> bfs(g);
for(std::vector<Edge>::reverse_iterator ei=arcs.rbegin();
ei!=arcs.rend();++ei)
{
Node a=g.u(*ei);
Node b=g.v(*ei);
g.erase(*ei);
bfs.run(a,b);
if(bfs.predArc(b)==INVALID || bfs.dist(b)>d)
g.addEdge(a,b);
else cnt++;
}
}
void sparse2(int d)
{
Counter cnt("Number of arcs removed: ");
for(std::vector<Edge>::reverse_iterator ei=arcs.rbegin();
ei!=arcs.rend();++ei)
{
Node a=g.u(*ei);
Node b=g.v(*ei);
g.erase(*ei);
ConstMap<Arc,int> cegy(1);
Suurballe<ListGraph,ConstMap<Arc,int> > sur(g,cegy);
int k=sur.run(a,b,2);
if(k<2 || sur.totalLength()>d)
g.addEdge(a,b);
else cnt++;
// else std::cout << "Remove arc " << g.id(a) << "-" << g.id(b) << '\n';
}
}
void sparseTriangle(int d)
{
Counter cnt("Number of arcs added: ");
std::vector<Parc> pedges;
for(NodeIt n(g);n!=INVALID;++n)
for(NodeIt m=++(NodeIt(n));m!=INVALID;++m)
{
Parc p;
p.a=n;
p.b=m;
p.len=(coords[m]-coords[n]).normSquare();
pedges.push_back(p);
}
std::sort(pedges.begin(),pedges.end(),pedgeLess);
for(std::vector<Parc>::iterator pi=pedges.begin();pi!=pedges.end();++pi)
{
Line li(pi->a,pi->b);
EdgeIt e(g);
for(;e!=INVALID && !cross(e,li);++e) ;
Edge ne;
if(e==INVALID) {
ConstMap<Arc,int> cegy(1);
Suurballe<ListGraph,ConstMap<Arc,int> > sur(g,cegy);
int k=sur.run(pi->a,pi->b,2);
if(k<2 || sur.totalLength()>d)
{
ne=g.addEdge(pi->a,pi->b);
arcs.push_back(ne);
cnt++;
}
}
}
}
template <typename Graph, typename CoordMap>
class LengthSquareMap {
public:
typedef typename Graph::Edge Key;
typedef typename CoordMap::Value::Value Value;
LengthSquareMap(const Graph& graph, const CoordMap& coords)
: _graph(graph), _coords(coords) {}
Value operator[](const Key& key) const {
return (_coords[_graph.v(key)] -
_coords[_graph.u(key)]).normSquare();
}
private:
const Graph& _graph;
const CoordMap& _coords;
};
void minTree() {
std::vector<Parc> pedges;
Timer T;
std::cout << T.realTime() << "s: Creating delaunay triangulation...\n";
delaunay();
std::cout << T.realTime() << "s: Calculating spanning tree...\n";
LengthSquareMap<ListGraph, ListGraph::NodeMap<Point> > ls(g, coords);
ListGraph::EdgeMap<bool> tree(g);
kruskal(g, ls, tree);
std::cout << T.realTime() << "s: Removing non tree arcs...\n";
std::vector<Edge> remove;
for (EdgeIt e(g); e != INVALID; ++e) {
if (!tree[e]) remove.push_back(e);
}
for(int i = 0; i < int(remove.size()); ++i) {
g.erase(remove[i]);
}
std::cout << T.realTime() << "s: Done\n";
}
void tsp2()
{
std::cout << "Find a tree..." << std::endl;
minTree();
std::cout << "Total arc length (tree) : " << totalLen() << std::endl;
std::cout << "Make it Euler..." << std::endl;
{
std::vector<Node> leafs;
for(NodeIt n(g);n!=INVALID;++n)
if(countIncEdges(g,n)%2==1) leafs.push_back(n);
// for(unsigned int i=0;i<leafs.size();i+=2)
// g.addArc(leafs[i],leafs[i+1]);
std::vector<Parc> pedges;
for(unsigned int i=0;i<leafs.size()-1;i++)
for(unsigned int j=i+1;j<leafs.size();j++)
{
Node n=leafs[i];
Node m=leafs[j];
Parc p;
p.a=n;
p.b=m;
p.len=(coords[m]-coords[n]).normSquare();
pedges.push_back(p);
}
std::sort(pedges.begin(),pedges.end(),pedgeLess);
for(unsigned int i=0;i<pedges.size();i++)
if(countIncEdges(g,pedges[i].a)%2 &&
countIncEdges(g,pedges[i].b)%2)
g.addEdge(pedges[i].a,pedges[i].b);
}
for(NodeIt n(g);n!=INVALID;++n)
if(countIncEdges(g,n)%2 || countIncEdges(g,n)==0 )
std::cout << "GEBASZ!!!" << std::endl;
for(EdgeIt e(g);e!=INVALID;++e)
if(g.u(e)==g.v(e))
std::cout << "LOOP GEBASZ!!!" << std::endl;
std::cout << "Number of arcs : " << countEdges(g) << std::endl;
std::cout << "Total arc length (euler) : " << totalLen() << std::endl;
ListGraph::EdgeMap<Arc> enext(g);
{
EulerIt<ListGraph> e(g);
Arc eo=e;
Arc ef=e;
// std::cout << "Tour arc: " << g.id(Edge(e)) << std::endl;
for(++e;e!=INVALID;++e)
{
// std::cout << "Tour arc: " << g.id(Edge(e)) << std::endl;
enext[eo]=e;
eo=e;
}
enext[eo]=ef;
}
std::cout << "Creating a tour from that..." << std::endl;
int nnum = countNodes(g);
int ednum = countEdges(g);
for(Arc p=enext[EdgeIt(g)];ednum>nnum;p=enext[p])
{
// std::cout << "Checking arc " << g.id(p) << std::endl;
Arc e=enext[p];
Arc f=enext[e];
Node n2=g.source(f);
Node n1=g.oppositeNode(n2,e);
Node n3=g.oppositeNode(n2,f);
if(countIncEdges(g,n2)>2)
{
// std::cout << "Remove an Arc" << std::endl;
Arc ff=enext[f];
g.erase(e);
g.erase(f);
if(n1!=n3)
{
Arc ne=g.direct(g.addEdge(n1,n3),n1);
enext[p]=ne;
enext[ne]=ff;
ednum--;
}
else {
enext[p]=ff;
ednum-=2;
}
}
}
std::cout << "Total arc length (tour) : " << totalLen() << std::endl;
std::cout << "2-opt the tour..." << std::endl;
tsp_improve();
std::cout << "Total arc length (2-opt tour) : " << totalLen() << std::endl;
}
int main(int argc,const char **argv)
{
ArgParser ap(argc,argv);
// bool eps;
bool disc_d, square_d, gauss_d;
// bool tsp_a,two_a,tree_a;
int num_of_cities=1;
double area=1;
N=100;
// girth=10;
std::string ndist("disc");
ap.refOption("n", "Number of nodes (default is 100)", N)
.intOption("g", "Girth parameter (default is 10)", 10)
.refOption("cities", "Number of cities (default is 1)", num_of_cities)
.refOption("area", "Full relative area of the cities (default is 1)", area)
.refOption("disc", "Nodes are evenly distributed on a unit disc (default)",
disc_d)
.optionGroup("dist", "disc")
.refOption("square", "Nodes are evenly distributed on a unit square",
square_d)
.optionGroup("dist", "square")
.refOption("gauss", "Nodes are located according to a two-dim Gauss "
"distribution", gauss_d)
.optionGroup("dist", "gauss")
.onlyOneGroup("dist")
.boolOption("eps", "Also generate .eps output (<prefix>.eps)")
.boolOption("nonodes", "Draw only the edges in the generated .eps output")
.boolOption("dir", "Directed graph is generated (each edge is replaced by "
"two directed arcs)")
.boolOption("2con", "Create a two connected planar graph")
.optionGroup("alg","2con")
.boolOption("tree", "Create a min. cost spanning tree")
.optionGroup("alg","tree")
.boolOption("tsp", "Create a TSP tour")
.optionGroup("alg","tsp")
.boolOption("tsp2", "Create a TSP tour (tree based)")
.optionGroup("alg","tsp2")
.boolOption("dela", "Delaunay triangulation graph")
.optionGroup("alg","dela")
.onlyOneGroup("alg")
.boolOption("rand", "Use time seed for random number generator")
.optionGroup("rand", "rand")
.intOption("seed", "Random seed", -1)
.optionGroup("rand", "seed")
.onlyOneGroup("rand")
.other("[prefix]","Prefix of the output files. Default is 'lgf-gen-out'")
.run();
if (ap["rand"]) {
int seed = int(time(0));
std::cout << "Random number seed: " << seed << std::endl;
rnd = Random(seed);
}
if (ap.given("seed")) {
int seed = ap["seed"];
std::cout << "Random number seed: " << seed << std::endl;
rnd = Random(seed);
}
std::string prefix;
switch(ap.files().size())
{
case 0:
prefix="lgf-gen-out";
break;
case 1:
prefix=ap.files()[0];
break;
default:
std::cerr << "\nAt most one prefix can be given\n\n";
exit(1);
}
double sum_sizes=0;
std::vector<double> sizes;
std::vector<double> cum_sizes;
for(int s=0;s<num_of_cities;s++)
{
// sum_sizes+=rnd.exponential();
double d=rnd();
sum_sizes+=d;
sizes.push_back(d);
cum_sizes.push_back(sum_sizes);
}
int i=0;
for(int s=0;s<num_of_cities;s++)
{
Point center=(num_of_cities==1?Point(0,0):rnd.disc());
if(gauss_d)
for(;i<N*(cum_sizes[s]/sum_sizes);i++) {
Node n=g.addNode();
nodes.push_back(n);
coords[n]=center+rnd.gauss2()*area*
std::sqrt(sizes[s]/sum_sizes);
}
else if(square_d)
for(;i<N*(cum_sizes[s]/sum_sizes);i++) {
Node n=g.addNode();
nodes.push_back(n);
coords[n]=center+Point(rnd()*2-1,rnd()*2-1)*area*
std::sqrt(sizes[s]/sum_sizes);
}
else if(disc_d || true)
for(;i<N*(cum_sizes[s]/sum_sizes);i++) {
Node n=g.addNode();
nodes.push_back(n);
coords[n]=center+rnd.disc()*area*
std::sqrt(sizes[s]/sum_sizes);
}
}
// for (ListGraph::NodeIt n(g); n != INVALID; ++n) {
// std::cerr << coords[n] << std::endl;
// }
if(ap["tsp"]) {
tsp();
std::cout << "#2-opt improvements: " << tsp_impr_num << std::endl;
}
if(ap["tsp2"]) {
tsp2();
std::cout << "#2-opt improvements: " << tsp_impr_num << std::endl;
}
else if(ap["2con"]) {
std::cout << "Make triangles\n";
// triangle();
sparseTriangle(ap["g"]);
std::cout << "Make it sparser\n";
sparse2(ap["g"]);
}
else if(ap["tree"]) {
minTree();
}
else if(ap["dela"]) {
delaunay();
}
std::cout << "Number of nodes : " << countNodes(g) << std::endl;
std::cout << "Number of arcs : " << countEdges(g) << std::endl;
double tlen=0;
for(EdgeIt e(g);e!=INVALID;++e)
tlen+=std::sqrt((coords[g.v(e)]-coords[g.u(e)]).normSquare());
std::cout << "Total arc length : " << tlen << std::endl;
if(ap["eps"])
graphToEps(g,prefix+".eps").scaleToA4().
scale(600).nodeScale(.005).arcWidthScale(.001).preScale(false).
coords(coords).hideNodes(ap.given("nonodes")).run();
if(ap["dir"])
DigraphWriter<ListGraph>(g,prefix+".lgf").
nodeMap("coordinates_x",scaleMap(xMap(coords),600)).
nodeMap("coordinates_y",scaleMap(yMap(coords),600)).
run();
else GraphWriter<ListGraph>(g,prefix+".lgf").
nodeMap("coordinates_x",scaleMap(xMap(coords),600)).
nodeMap("coordinates_y",scaleMap(yMap(coords),600)).
run();
}