[R] possible bug with largest.cliques in igraph_0.6-3

[Gábor Csárdi]

Indeed this seems to be a bug, if the graph is directed. The
workaround is to convert it to an undirected graph, the clique
computation ignores direction anyway:

library(igraph)
adj <- matrix(1, nrow=11, ncol=11) - diag(11)
g <- graph.adjacency(adj)
largest.cliques(g)
# [[1]]
#  [1] 10  8  1
#
# [[2]]
#  [1] 9 7 1
#
# [[3]]
#  [1] 8 7 1

largest.cliques(as.undirected(g))
# [[1]]
#  [1]  1  2  3  4  5  6  7  8  9 10 11

Btw. please do not send igraph bug reports to r-help, either send them
to igraph-help (see http://igraph.sf.net), to me directly, or, the
best for us, report the bug at https://bugs.launchpad.net/igraph.
Thanks.

I have reported a bug for this, you can follow it here, in case you
are interested:
https://bugs.launchpad.net/igraph/+bug/1073800

On Wed, Oct 31, 2012 at 11:15 PM, Christos Hatzis
<christos.hatzis at nuverabio.com> wrote:
> There is a problem with the largest clique computation in the recent version
> of igraph.
[...]