Re: [igraph] Re: Question about community detection

[zhengjun chen]

Thanks a lot. Appreciate your help. I get the results. The last thing I want to make sure is that the membership records the community ID of each vertex. It is ordered in increasing vertex id. Right?

On Tue, Dec 22, 2009 at 10:20 AM, Gábor Csárdi <address@hidden> wrote:

On Tue, Dec 22, 2009 at 4:11 PM, zhengjun chen <zhjchen.sa@gmail.com> wrote:
> 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));

Maybe this should be fprintf(file2,"%d ", (int) MATRIX(mat,i,k));
Actually, it is better to send self-contained code that we can compile
and run easily.

G.

>         }
>         fprintf(file2,"\n");
>      }
>      fclose(file2);
> I am puzzled that where is wrong?
> On Tue, Dec 22, 2009 at 9:48 AM, Gábor Csárdi <address@hidden> 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
>> >>
>> >>
>> >>
>> >> _______________________________________________
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>> >
>> >
>> >
>> > --
>> > Thanks
>> > zhengjun
>> >
>> > Graduate research assistant
>> > Dept of Computer Science and Engineering
>> > Lehigh University
>> >
>> > _______________________________________________
>> > igraph-help mailing list
>> > address@hidden
>> > http://lists.nongnu.org/mailman/listinfo/igraph-help
>> >
>> >
>>
>>
>>
>> --
>> Gabor Csardi <address@hidden>     UNIL DGM
>>
>>
>> _______________________________________________
>> igraph-help mailing list
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>
>
>
> --
> Thanks
> zhengjun
>
> Graduate research assistant
> Dept of Computer Science and Engineering
> Lehigh University
>
> _______________________________________________
> igraph-help mailing list
> address@hidden
> http://lists.nongnu.org/mailman/listinfo/igraph-help
>
>



--
Gabor Csardi <address@hidden>     UNIL DGM


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-- 
Thanks
zhengjun

Graduate research assistant
Dept of Computer Science and Engineering
Lehigh University