graph-tool December 2010

graph-tool@skewed.de

3 participants
3 discussions

Segmentation fault using shortest_distance
by Juan Manuel Tirado 20 Mar '16

20 Mar '16

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

5 9

Parallel Processing
by Derek Ditch 21 Nov '13

21 Nov '13

I want to use graph-tool using the multiprocessing library in Python 2.6. I keep running into issues though with trying to share a full graph object. I can store the graph in a multiprocessing.Namespace, but it doesn't keep the dicts of properties. Example: def initNS( ns ): _g = Graph( directed = False) ns.graph = _g ns.edge_properties = { 'genres': _g.new_edge_property("vector<string>"), 'movieid': _g.new_edge_property("int"), } ns.vertex_properties = { 'personid': _g.new_vertex_property("int32_t") } """ Build property maps for edges and vertices to hold our data The graph vertices represent actors whereas movies represent edges """ # Edges _g.edge_properties["genres"] = ns.edge_properties['genres'] _g.edge_properties["movieid"] = ns.edge_properties['movieid'] # Vertices _g.vertex_properties["personid"] = ns.vertex_properties['personid'] ns.graph = _g ########## This initializes 'ns', which is a multiprocessing.Namespace. The problem is that for example, ns.edge_properties[ * ] tells me that the type isn't pickle-able. I tried to just skip that and use the _g.edge_properties to access it, but those dicts aren't carried over to the different process in the pool. Presumably b/c they aren't pickle-able. Any thoughts about how to fix this? (For those interested, I'm attempting to use the IMDbPy library to do some graph analysis on the relationships among actors and movies. Each process has it's own db connection and trying to populate the graph with actor and movie information in parallel since it's a pretty large and dense graph. Somewhere in the neighborhood of 250,000+ vertices for just a depth of three relationships) Thanks, -- Derek

3 7

basic subroutines: dfs, dijstra, etc
by Rafael M. Frongillo 05 Dec '10

05 Dec '10

Hi all, I'm hoping to use graph-tool for a project involving huge graphs, but I can't seem to find simple routines like depth-first search and Dijkstra's algorithm in the documentation. I noticed that these are listed under milestone 2.2 -- are they not yet implemented? Apologies if the answer lies in the documentation or this mailing list; I have searched in vain for some time. I'd hate to turn to a much slower library for want of these simple routines... graph-tool looks perfect otherwise! Rafael

2 3

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

2012

2011

2010

2009

2008

2007

2006

graph-tool December 2010