Re: [igraph] Non-Backtracking Matrix

[Tamás Nepusz]

Hello,  

For me it seems that the non-backtracking matrix that you are looking for is 
essentially the adjacency matrix of the line graph of the original graph sans 
the entries that represent length-2 loops. I think you can make use of the 
existing functions in igraph that produce the line graph and the adjacency 
matrix of an arbitrary graph (and then set the entries representing length-2 
loops to zero).  

--  
T.


On Tuesday, 28 January 2014 at 15:20, Pierre-Andre Maugis wrote:

> Hello,
>  
> I am trying to build the non-backtracking matrix of a network. It is the 
> matrix whose entries are indexed by the edges of the graph. Entries are 0 if 
> the said edges do not form a path of length two, and 1 if they do. More 
> details can be found in arXiv:1306.5550, p3.  
>  
> All the algorithms I could produce are very slow. Computing the entries is 
> not a problem, however storing them properly in the matrix is, and takes a 
> lot of time.
>  
> I would welcome any suggestion on the topic.  
> Best,
> Pierre-André Maugis
>  
>  
> _______________________________________________
> igraph-help mailing list
> address@hidden (mailto:address@hidden)
> https://lists.nongnu.org/mailman/listinfo/igraph-help