[igraph] Sneppen-Maslov Randomization

[Lorenzo Isella]

Dear All,
I saw on the documentation that igraph is able to generate a random 
graph with a given degree distribution P(k).
However, I would like to know if there is already an implementation (in 
particular for igraph under R) of the Sneppen-Maslov algorithm, a 
randomization technique that preserves P(k).
The idea is relatively simple: given the edges i--j and k--l, I change 
them into i--l and k--j.
It should not be terribly difficult to implement from scratch, but I 
know there are a few tricky issues e.g.:
(1) i, j, k and l must be 4 distinct nodes
(2) there should not be any existing i--l or k--j edge, otherwise I 
would destroy a former link an re-create an existing link.
(3) Given e.g. a graph with 1000 edges, how many i--j and k--l  ----> 
i--l and k--j valid edge transformations should I perform
before I can consider the graph randomized?

Many thanks

Lorenzo