Finding cycle of 3 nodes ( or triangles) in a graph

Question

I am working with complex networks. I want to find group of nodes which forms a cycle of 3 nodes (or triangles) in a given graph. As my graph contains about million edges, u

Answer 1

Assuming its an undirected graph, the answer lies in networkx library of python. if you just need to count triangles, use:

import networkx as nx
tri=nx.triangles(g)

But if you need to know the edge list with triangle (triadic) relationship, use

all_cliques= nx.enumerate_all_cliques(g)

This will give you all cliques (k=1,2,3...max degree - 1)

So, to filter just triangles i.e k=3,

triad_cliques=[x for x in all_cliques if len(x)==3 ]

The triad_cliques will give a edge list with only triangles.