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## Re: [igraph] Re: Question about community detection

 From: zhengjun chen Subject: Re: [igraph] Re: Question about community detection Date: Tue, 22 Dec 2009 10:11:34 -0500

I run fastgreedy function, but the result shows that the merges matrix I got is all zero....
The following is my part code:

igraph_simplify(&graph,1,1);
igraph_community_fastgreedy(&graph,NULL,&mat,NULL);
nrow=igraph_matrix_nrow(&mat);
printf("the number of rows is: %d\n",nrow);
for(i=0;i<nrow;i++)
{
for(k=0;k<2;k++)
{   fprintf(file2,"%d ",MATRIX(mat,i,k));
}
fprintf(file2,"\n");
}
fclose(file2);

I am puzzled that where is wrong?

On Tue, Dec 22, 2009 at 9:48 AM, Gábor Csárdi wrote:
If you want the maximum modularity, then look for the maximum value in
the modularity vector returned by the community detection and give
that as a parameter.

G.

On Tue, Dec 22, 2009 at 3:45 PM, zhengjun chen <zhjchen.sa@gmail.com> wrote:
> Thanks. Another problem is how to set this step value in
> "igraph_community_to_
> membership"? The document said it is prescribed by the matrix.
>
> On Tue, Dec 22, 2009 at 9:36 AM, Tamas Nepusz <address@hidden> wrote:
>>
>> > There is a parameter "nodes" in this function. It means the number of
>> > leaf nodes in the dendrogram. I do not understand it.... So, how can I know
>> > the number of leaf nodes in the dendrogram?
>> It is exactly as many as the number of vertices in your graph (since each
>> vertex will become a node in the dendrogram).
>>
>> --
>> Tamas
>>
>>
>>
>> _______________________________________________
>> igraph-help mailing list
>> http://lists.nongnu.org/mailman/listinfo/igraph-help
>
>
>
> --
> Thanks
> zhengjun
>
> Dept of Computer Science and Engineering
> Lehigh University
>
> _______________________________________________
> igraph-help mailing list
> http://lists.nongnu.org/mailman/listinfo/igraph-help
>
>

--

_______________________________________________

--
Thanks
zhengjun