Wow!! Thank you very much, Tamás! It is a lot of valuable information!!! I guess I have a lot to study this weekend! :)
By the way, I was "translating" some Igraph-R-code to Igraph-C-code in order to use the advantages of C in working with larger matrices. But using this version of Igraph for C (version 0.6) I was wondering some points: First, I was wondering if Igraph considers IGRAPH_INFINITY as zero or as other value. I am working with shortest-paths matrices and I would like the distance between two vertices that can not reach each other to be zero. Besides of that, I am using some igraph-functions to manipulate matrices (they are very good, thank you for sharing it!!). I thought about using the function "igraph_matrix_scale" to divide a matrix by a scalar value just by using a number between 0 and 1 as the "by" parameter. But I realized that the function only accepts integer values (I tryied to do "igraph_matrix_scale(matrix,1./2)" and it gave me a zero-matrix). I would like to "divide" the shortest path matrix by the diameter of the network. Is there any way to do it? Sorry for the inconvenience, and thank you again for all your valuable help! Best, Charles On Tue, Dec 4, 2012 at 8:27 PM, Tamás Nepusz <[email protected]> wrote: >> If I remember right, some months ago somebody posted here about >> measures to compare networks. I looked for this post in the historial >> of the list, but I didn't find it, sorry. > This is a thread that seems related, although it is quite old: > > http://lists.gnu.org/archive/html/igraph-help/2008-04/msg00009.html > > However, the conclusion is still the same: there is no built-in network > comparison measure in igraph right now. Besides the options mentioned in that > particular thread, another possibility is to calculate the top few > eigenvalues and eigenvectors of the adjacency matrix of the graph, and then > compare these values and vectors. Others have studied this in much greater > detail than me so I'd recommend to Google for "spectral graph comparison" if > you are interested. This paper could be a good starting point: > > http://www.comp.leeds.ac.uk/bmvc2008/proceedings/2005/papers/162/bmvc2005b.pdf > > You can also compare the motif profiles of the graphs: > > http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0015765 > > Yet another option that comes to my mind is to use some technique that > compresses the graph into a much smaller matrix while preserving the most > important structural features and then compare the matrices: > > http://arxiv.org/abs/cond-mat/0703470 > > Best, > T. > > > > _______________________________________________ > igraph-help mailing list > [email protected] > https://lists.nongnu.org/mailman/listinfo/igraph-help -- Um axé! :) -- Charles Novaes de Santana http://www.imedea.uib-csic.es/~charles PhD student - Global Change Laboratorio Internacional de Cambio Global Department of Global Change Research Instituto Mediterráneo de Estudios Avanzados(CSIC/UIB) Calle Miquel Marques 21, 07190 Esporles - Islas Baleares - España Office phone - +34 971 610 896 Cell phone - +34 660 207 940 _______________________________________________ igraph-help mailing list [email protected] https://lists.nongnu.org/mailman/listinfo/igraph-help
