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[kloffy <>]

Hi,

I am trying to get my head around combinatorial maps, and I thought I would
start with the simplest non-trivial example, a 1-simplex (#0-cells=2,
#1-cells=1).


So, first I tried the obvious construction helper:

CGAL::Combinatorial_map<1> cm;

cm.make_edge();

cm.display_characteristics(std::cout);
std::cout << std::endl;

However, this gives me:

#Darts=2, #0-cells=2, #1-cells=2, #ccs=2

But that's not quite right (#1-cells=2).


So I tried creating the 1-simplex manually:

CGAL::Combinatorial_map<1> cm;

auto dh1 = cm.create_dart();
auto dh2 = cm.create_dart();

cm.dart_link_beta<0>(dh1, dh2);
cm.dart_link_beta<0>(dh2, dh1);

cm.display_characteristics(std::cout);
std::cout << std::endl;

However, this gives me:

#Darts=2, #0-cells=2, #1-cells=2, #ccs=1

But that's still not quite right (#1-cells=2).


I tried a bunch of other things, but I never managed to get the intended
result (#1-cells=1). My intuition for combinatorial maps is still very poor,
which was the motivation for this exercise. At this point, I feel like I
must be missing something. Please forgive me if it is something very
obvious. Still, I would appreciate any hints...

Cheers,
Peter



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