[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [igraph] knn computation

From: Szabolcs Horvát
Subject: Re: [igraph] knn computation
Date: Tue, 23 Jan 2018 21:10:08 +0100

Hi Filippo,

The message means that your graph has either self-loops (an edge
connecting a vertex to itself), or parallel edges connecting the same
two vertices. The function does not work on such graphs.  You need to
supply a simple graph—take a look at simplify().

Also, be aware that knn() does not compute the mean neighbour strength
for weighted graphs.  https://github.com/igraph/igraph/issues/987


On 23 January 2018 at 19:29, Filippo Santi <address@hidden> wrote:
> Dear all,
> I am new to R and even more to igraph. I am working on foreign direct
> investment network, and I am currently  trying to compute average nearest
> neighbour degree and average nearest neighbour strength, using the knn
> function. My code is as following:
> fdi.graph.2003 <- graph_from_data_frame(fdi.edge.2003, directed = T,
> vertices = fdi.attr.2003)
> ANND <- knn(fdi.graph.2003)
> However, R returns the following error message
> Error in knn(fdi.graph.2003) :
> At structural_properties.c:5889 : Average nearest neighbor degree Works only
> with simple graphs, Invalid value
> Do you have any explanation to try to solve this issue? I tried to compute
> it building the graph from a simple binary edgelist too (the above message
> comes from computations based on a weighted network with plenty of edge
> attributes, built from a data.frame) but it is not working either.
> Thanks for any help,
> Filippo
> _______________________________________________
> igraph-help mailing list
> address@hidden
> https://lists.nongnu.org/mailman/listinfo/igraph-help

reply via email to

[Prev in Thread] Current Thread [Next in Thread]