Re: [igraph] Question about splitting network

[Tamas Nepusz]

Dear Zhigang,

> I have a question about splitting a network. In fact, I am developing
> a program to solve the electrical power flow via grid-computing
> technique. First of all, I have to split the network into several
> parts as average as possible,
igraph contains no functions to cut a graph into roughly equal pieces
(especially because equality can be measured in a variety of different
ways, e.g., one could strive for placing the same amount of nodes in
each partition, or the same amount of edge weight, or some other measure
may be optimised). However, igraph contains seveeral heuristics to find
communities (clusters, dense subgraphs) in large graphs. See the
following functions as a starting point (these are the names from the
C library, the names in the R and Python interfaces are similar):

http://igraph.sourceforge.net/doc/html/igraph-Community.html

The spinglass, walktrap and fast greedy methods definitely support edge
weights. These methods do not strive to create approximately "equal"
parts, but you can either specify the desired number of parts in
advance, or let the algorithms find out the optimal cluster count. In
the latter case, if you only need k parts, you can start merging the
smaller ones until you get the desired number of clusters.

Hope this helps.

Best,
Tamas