Re: [igraph] Re: Question about community detection

[Gábor Csárdi]

Yes,

vertex 0 is in community 'membership[0]'
vertex 1 is in community 'membership[1]'
etc.

G.

On Tue, Dec 22, 2009 at 4:43 PM, zhengjun chen <address@hidden> wrote:
> 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 <address@hidden>
>> 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 <address@hidden>
>> >> 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
>> >> >> address@hidden
>> >> >> http://lists.nongnu.org/mailman/listinfo/igraph-help
>> >> >
>> >> >
>> >> >
>> >> > --
>> >> > 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
>> >> address@hidden
>> >> http://lists.nongnu.org/mailman/listinfo/igraph-help
>> >
>> >
>> >
>> > --
>> > 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
>> address@hidden
>> http://lists.nongnu.org/mailman/listinfo/igraph-help
>
>
>
> --
> 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