Hi Tiago,

I'm experimenting some problems with the remove_parallel_edges function. It seems that some edges are removed randomly. I attach some reproducible code to test.

Let's suppose the following dot graph file:

graph G{
1--2
2--1
1--3
3--1
2--3
3--2
}

It is basically an undirected graph with a triangle shape with parallel edges. The following code loads the graph, removes parallel edges and calculate clustering coefficient. I repeat it ten times.

for i in range(0,10):
    aux = gt.load_graph("/tmp/sampleGraph.dot",format="dot")
    gt.remove_parallel_edges (aux)
    clust=gt.local_clustering (aux)
    gt.vertex_average (aux,clust)

This operation is supposed to generate a tuple (1.0, 0.0), the problem is that randomly the generated output is wrong. For example:

Out[111]: (1.0, 0.0)
Out[111]: (1.0, 0.0)
Out[111]: (1.0, 0.0)
Out[111]: (1.0, 0.0)
Out[111]: (0.0, 0.0)
Out[111]: (1.0, 0.0)
Out[111]: (1.0, 0.0)
Out[111]: (1.0, 0.0)
Out[111]: (1.0, 0.0)
Out[111]: (1.0, 0.0)

I have plotted the graph and I have found, that sometimes one edge is completely removed modifying the final result.

I attach my show_config output.

gt.show_config ()
version: 2.2.5 (commit 3ba24072, Sun Feb 21 00:46:41 2010 +0100)
gcc version: 4.4.1
compilation flags: -I/usr/include/python2.6 -I/usr/include -I/usr/lib/python2.6/dist-packages/numpy/core/include/numpy -I/usr/lib/python2.6/dist-packages/scipy -O3 -Wall -ftemplate-depth-150 -Wno-deprecated -O99 -fvisibility=default -fvisibility-inlines-hidden -fopenmp -Wl,-Bsymbolic-functions -L/usr/lib/python2.6 -lpython2.6
install prefix: /usr
python dir: /usr/lib/python2.6/dist-packages
graph filtering: True
openmp: True
uname: Linux host 2.6.31-22-generic #60-Ubuntu SMP Thu May 27 02:41:03 UTC 2010 x86_64

Kind regards,

Juan

================================
Juan Manuel Tirado
2.2.C02.B
+34 91 624 6260
Computer Department
Computer Architecture Group
http://www.arcos.inf.uc3m.es
University Carlos III of Madrid
http://www.uc3m.es
================================