Re: [igraph] python: Graph.add_edges too slow

[Gábor Csárdi]

Davide,

add_edges takes the same time, irrespectively of the number of edges
you add. More precisely the time complexity is O(|V|+|E|), where (V,E)
is the new, extended graph. So the solution is to add all edges at the
same time, in one go.

Best,
Gabor

On Mon, Jun 29, 2009 at 2:31 PM, Davide Setti<address@hidden> wrote:
> Hi all,
> i'm trying to create a network with python-igraph. While the import
> functions (like pajek or dot) are very fast, the creation "from
> scratch" of the network is really slow. By profiling my code with the
> cProfile module i see the bottleneck is the add_edges function. I
> think the problem is the size of the network. You can find a simple
> test code here:
>
> http://github.com/vad/network-libraries-test/blob/2d4fff545655d1abb3622dc15478b3df0d607841/igraph-add-edge.py
>
> This takes 17m on my core2duo, while the import of a 130k nodes/400k
> edges .dot only takes a few seconds.
>
> I think there should be a solution, because of the fast import
> functions. Maybe these functions can disable some checks?
>
> (i'm using a trunk version of 2 weeks ago)
>
> Regards.
> --
>
> Davide Setti
> blog: http://blog.flatlandia.eu
> home: http://www.flatlandia.eu
>
>
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>



-- 
Gabor Csardi <address@hidden>     UNIL DGM