[igraph] question about igraph_watts_strogatz_game

[Wu Degang]

Hi,

I created a small world graph using:

igraph_watts_strogatz_game(&graph, 1, 20, 4, 0.3);

but when I inspected the neighbors of node with pnode=1 by

igraph_neighbors(&graph, &neis, 1, IGRAPH_ALL);
...
for (int i=0;i<igraph_vector_size(&neis);++i)
        cout << VECTOR(neis)[i] << ' ';

I got the output

3 5 5 9 11 16 17 18.

Why are there two 5's? I remember that duplicate edges are forbidden in 
the paper by Watts and Strogatz.



Wu Degang