Re: [igraph] motifs

[Tamas Nepusz]

Hi and sorry for the late reply, this email has fallen through the
cracks somehow. (I was on the road in China for a few weeks with
limited internet access).

> On the other hand, motifs() returns a vector with the number of occurences
> of each motif in the graph ordered by their isomorphism class. How do I know
> which isomorphism class are present in my graph. I mean, a possible result
> of motifs(graph, size =3) could be something like this:
>> NA NA 32 18
>
> For me, this means that there are 32 motifs of x-isomorphic class and other
> 18 motifs of y-isomorphic class. But, which classes?
The i-th element of the vector corresponds to the motif with
isomorphism class i. So, you can indeed use
graph_from_isomorphism_class() to figure out how the motif looks like.
The only catch is that, unlike everything else in R, isomorphism
classes are zero-based, so the two NAs belong to isomorphism classes 0
(empty graph) and 1 (two vertices connected, and a third isolated
vertex), and then you have 32 occurrences of isomorphism class 2 (V
shape) and 18 occurrences of isomorphism class 3 (full triangle).

T.