Re: [igraph] sample graph via random walk

[Tamás Nepusz]

No, there isn't, as far as I know. If you are using igraph from Python, here's 
a quick implementation of a random walk iterator:

import random

def random_walk(g, start=None):
    current = random.randint(0, g.vcount()-1) if start is None else start
    stop = False
    while not stop:
        stop = yield current
        current = random.choice(g.successors(current))

You can then combine this with itertools.islice() to get a random walk with a 
given length:

vs = list(islice(random_walk(g, start=5), desired_length))

and then you can take the subgraph:

g2 = g.induced_subgraph(vs)

But the iterator also lets you stop the random walk when you reach a given 
vertex if you combine it with itertools.takewhile() instead:

destination = 20
vs = list(takewhile(lambda x: x != destination, random_walk(g, start=5))) + 
[destination]

--  
T.

------------------------------------------------------
From: Николай Кинаш address@hidden
Reply: Help for igraph users address@hidden
Date: 10 July 2014 at 05:33:47
To:address@hidden address@hidden
Subject:  [igraph] sample graph via random walk

> Hi all.
>  
> Is there a built-in function to get subgraph from random walk on graph?
>  
> Thanks.
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