Hi Tiago,

I am trying to calculate the shortest distances of a graph after applying a filter. I have a code that looks like this:

g=gt.load_graph("myGraph.xml",format="xml")

#for later use
distances = gt.shortest_distance(g)

#extract the components of the graph
comp = g.label_components(g)
#This splits the graph in several components
#I want to calculate the shortest distances
#for the component 2 for example

filtering = g.new_vertex_property("boolean")
for v in g.vertices():
   if comp[v]==2:
      filtering[v]=True
   else:
      filtering[v]=False

#set the vertex filter
g.set_vertex_filter(filtering)
distances_comp=gt.shortest_distance(g)

The last line of code rises a segmentation fault. I have plotted the graph with the filtered graph and its correct, also I can calculate the local_clustering_coefficient without problems. Am I doing something wrong? Is there any other way to filter the graph and calculate the shortest distances? Is this a bug?

Thanks so much,

Juan

Here it is the output from the show_config()

 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 2.6.32-23-generic #37-Ubuntu SMP Fri Jun 11 08:03:28 UTC 2010 x86_64


I am using the code from the ubuntu package, so I'm not using the latest 2.2.6 version. I will try to install and make a test with the latest version, as I see it is not available via apt-get.

I have just made a small test. Instead of passing the filtered graph to the shortest_distance function, I have generated a copy of the filtered graph and it works fine.

It seems that exist a problem with the shortest_distance function.

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
================================

Thanks your for great work Tiago.

Cheers,

Juan