Re: [igraph] Correlating nodes with high betweenness

[Gábor Csárdi]

Hi Anupam,

you need to supply a list of vertex ids to 'subgraph', and not a
TRUE/FALSE logical vector like you did. I.e.

bet <- betweenness(met_eco)
subg <- subgraph(met_eco, which(bet>5000)-1)

The '-1' is needed because igraph vertex ids start from zero.

Best,
G.

On Wed, Dec 9, 2009 at 9:41 AM, anupam sinha <address@hidden> wrote:
> Hi all,
>           Thanks a lot  for your suggestions. I am getting some problems in
> implementation though. I have tried the following codes in R . But none seem
> to be working.....
>
> 1.
>> subg<-subgraph(met_eco,(betweenness=betweenness(met_eco))>5000)
>> subg
> Vertices: 2
> Edges: 2
> Directed: TRUE
> Edges:
>
> [0] 'eco:b4069' -> 'eco:b4069'
> [1] 'eco:b4069' -> 'eco:b1241'
>
> 2.
>       > subg<-subgraph(met_eco,betweenness(met_eco)>5000)
>
>> subg
> Vertices: 2
> Edges: 2
> Directed: TRUE
> Edges:
>
> [0] 'eco:b4069' -> 'eco:b4069'
> [1] 'eco:b4069' -> 'eco:b1241
>
>
>
>
> On Tue, Dec 8, 2009 at 5:23 AM, Arun <address@hidden> wrote:
>>
>> betweenness_list = g.betweenness()
>> your_answer = []
>> for e in g.es:
>>    v1 = e.tuple[0]
>>    v2 = e.tuple[1]
>>    if betweenness_list[v1] > threshold and betweenness_list[v2] >
>> threshold:
>>        your_answer.append(e)
>>
>>
>>
>> On Mon, Dec 7, 2009 at 10:29 AM, anupam sinha <address@hidden>
>> wrote:
>> >
>> > Hi all,
>> >           I have a network of the following format :
>> >
>> > eco:b4069 eco:b4069
>> > eco:b4069 eco:b1241
>> > eco:b4069 eco:b0115
>> > eco:b4069 eco:b3256
>> > eco:b4069 eco:b0185
>> > eco:b4069 eco:b2316
>> >
>> > where each of the alphanumeric value is a node id. I calculate the
>> > betweenness of the nodes. My query though is how do I find pairs of
>> > nodes
>> > which are connected to each other and have betweenness values above a
>> > certain threshold ?
>> > Thanks in advance.
>> >
>> >
>> > Regards,
>> >
>> >
>> > Anupam
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>> > _______________________________________________
>> > igraph-help mailing list
>> > address@hidden
>> > http://lists.nongnu.org/mailman/listinfo/igraph-help
>> >
>> >
>>
>>
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>
>
>
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-- 
Gabor Csardi <address@hidden>     UNIL DGM