🚀 go-pugleaf

In article <44ne7b$52v@sundog.tiac.net> Sid <mebaga@unix1.sncc.lsu.edu> writes:

[...]

>> I want to be able to use the very powerful graph planarity testing
>> program planar.c.  But, I want to be able to read the graph from a
>> file. I could not find any information about how to define the
>> datafile.  I will be using it on undirected and unweighted graphs.
>> For example: K3(Complete graph on 3 vertices)

The simplest way: use `ged', the Graph EDitor which comes with LEDA,
to draw your graphs. If you want to define them otherwise, look at the
result of ged.

I did it for long with version 3.1.1 of LEDA.
The format is the following:
1) A first line with the words "LEDA.GRAPH"
2) 2nd line with the name of the type for the nodes, for instance
   "point" in the graphs edited with `ged'.
3) 3rd line with the name of the type for the edges, for instance
   "int" in the graphs edited with `ged'.
4) 4th line with the number `n' of nodes
5) `n' lines, each with the representation of a node.
6) A line with the number `e' of edges
7) `e' lines with the rank of the source node in the list cited in 5),
   a space, the rank of the sink, a space, and the representation of
   the edge.

It is certainly clearer with a small example:

Suppose the following graph is a GRAPH<FirstName,int>

                      (Amandine)
                      /  |  \
                   2 /   |   \7
                     |   |   |
                     V   |8  V
               (Bernard) |  (Christine)
                     |   |   |
                    3 \  |  /4
                       V V V
                      (Elise)

should give:

---------------
LEDA.GRAPH
FirstName
int
4
Amandine
Bernard
Christine
Elise
5
1 2 2
1 3 7
1 4 8
2 4 3
3 4 4
---------------

[...]
>> Sid Bagali

						Olivier L'Heureux

----------------------------------------------------------------------

Laboratoire de microélectronique de l'Université catholique de Louvain

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