Re: [igraph] Transitivity Triples

[Gábor Csárdi]

Riccardo,

the number of transitive triplets you can get easily with
triad.census. The number of balanced triplets is more difficult. The
igraph transitivity could be modified to do this, but that is in C,
not in R.

Btw. you might be interested in this thread:
http://markmail.org/message/dgobdxsyfjeocy54#query:r-help tom
balanced+page:1+mid:6yx3bc5qyvm3stb5+state:results

The last message has some R code for a similar problem, but it is a
very slow brute-force method, it only helps if your graphs are small.

The other thing that you could try is to formalize the problem with
matrix multiplications (probably possible), and then work on the
adjacency matrix. The 'Matrix' package has sparse matrices. This would
work a bit larger graphs as well.

Gabor



On Thu, Dec 11, 2008 at 4:17 PM, Riccardo Tasso <address@hidden> wrote:
> Hi,
>   I'm working on a weighted directed network (with positive and negative
> links) and I'd like to count the occurrence of the following pattern.
> Given a transitive triple (in the form A->B->C, A->C), a "balanced triple"
> is a triple for which weight(A->B)*weight(B->C)*weight(A->C) > 0.
> My task is to count the number of all the transitive triples and the number
> of all the balanced triples in my network.
> Can you help me implementing this function in R using igraph?
>
> Thank you,
>   Riccardo
>
>
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>



-- 
Gabor Csardi <address@hidden>     UNIL DGM