Thank you very much; I had a hunch it had something to do w/default parameters but was unsure how the library handled them. I appreciate the help, Emily Message: 3 Date: Tue, 29 Sep 2009 17:07:30 -0400 (EDT) From: Jeremiah Willcock To: boost-users@lists.boost.org Subject: Re: [Boost-users] request for help re: brandes_betweenness_centrality for weighted graph Message-ID: Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed On Tue, 29 Sep 2009, allenem@pcbi.upenn.edu wrote:

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Hi-

I've just recently started to use the BGL and was wondering if someone could provide an example (and/or just let me know where I am going wrong) in trying to execute the brandes_betweenness_centrality algorithm for a weighted graph. Below are the relevant code snippets from my program. I am able to compile and run the code, and have successfully iterated over all elements (vertices, edges, and "interaction_weights" to verify that the data are stored correctly) but the calculated betweenness values are the same whether or not I use the edge weight map, which suggests that they are not being considered in the calculation even when passed as a parameter to the brandes_betweenness_centrality function. What am I missing?

The three-parameter version of brandes_betweenness_centrality has its third parameter as the (output) edge centrality map, not the weight map which you are trying to provide. Try using the named parameter version (as shown on URL:http://www.boost.org/doc/libs/1_40_0/libs/graph/doc/betweenness_centrali...). How to provide named parameters is described at URL:http://www.boost.org/doc/libs/1_40_0/libs/graph/doc/bgl_named_params.htm.... -- Jeremiah Willcock