On Thu, Apr 5, 2012 at 7:40 AM, Peter Flom <[email protected]> wrote: > Thanks Tamas > > That brings up a suggestion - in the next version of the manual it would be > nice to see, for each measure, a rough idea of running time. Obviously, this > couldn't be precise as it depends on the machine running the code and > probably on lots of other things, but something indicating that betweenness > centrality running time is proportional to links*nodes, whereas degree seems > to be linear in nodes (from what I can tell) and similar for other measures.
You are right, this should be in the manual. It is included in the C manual for most functions: http://igraph.sourceforge.net/doc/html/index.html and the R running time complexity is almost always the same. Betweenness is O(nm), the number of nodes times the number of edges: http://igraph.sourceforge.net/doc/html/igraph_betweenness.html Gabor > Thanks again > > Peter Flom > Peter Flom Consulting > http://www.statisticalanalysisconsulting.com/ > http://www.IAmLearningDisabled.com > > -----Original Message----- > From: igraph-help-bounces+peterflomconsulting=mindspring....@nongnu.org > [mailto:igraph-help-bounces+peterflomconsulting=mindspring....@nongnu.org] > On Behalf Of Tamás Nepusz > Sent: Thursday, April 05, 2012 7:35 AM > To: Help for igraph users > Subject: Re: [igraph] Working with large networks and how to sample from a > graph? > >> > Thanks >> > >> > These big networks are hard! My past experience is with networks of >> > a couple hundred nodes, at most >> > > Another thing you might want to think about is whether you really need the > betweenness centrality of the nodes or it is enough to use _any_ sensible > centrality measure. For instance, eigenvector centrality and PageRank can be > calculated way faster than betweenness centrality or closeness centrality on > large networks. > > T. > > > > _______________________________________________ > igraph-help mailing list > [email protected] > https://lists.nongnu.org/mailman/listinfo/igraph-help > > > _______________________________________________ > igraph-help mailing list > [email protected] > https://lists.nongnu.org/mailman/listinfo/igraph-help -- Gabor Csardi <[email protected]> MTA KFKI RMKI _______________________________________________ igraph-help mailing list [email protected] https://lists.nongnu.org/mailman/listinfo/igraph-help
