Optimal Community Detection

Finds the optimal community structure by maximizing modularity exactly. Very slow - only use for small networks (<50 nodes).

Usage

community_optimal(x, weights = NULL, ...)

com_op(x, weights = NULL, ...)

Arguments

x

Network input

weights

Edge weights. NULL uses network weights, NA for unweighted.

...

Additional arguments passed to to_igraph

Value

A cograph_communities object

A cograph_communities object. See detect_communities.

Note

This is an NP-hard problem. Use only for tiny networks.

References

Brandes, U., Delling, D., Gaertler, M., Gorke, R., Hoefer, M., Nikoloski, Z., & Wagner, D. (2008). On modularity clustering. IEEE Transactions on Knowledge and Data Engineering, 20(2), 172-188.

Examples

g <- igraph::make_ring(10)
comm <- community_optimal(g)
igraph::membership(comm)
#>  [1] 1 1 2 2 2 3 3 3 3 1
net <- as_cograph(matrix(runif(25), 5, 5))
com_op(net)
#> Community structure (optimal)
#>   Number of communities: 2 
#>   Modularity: 0.2432 
#>   Community sizes: 4, 1 
#>   Nodes: 5