ModularityBP Object

We have created a single Python object, modbp.ModularityBP

  1. Store graphs on ModularityBP Object
  2. Run modularity belief propagation
  3. Access discovered partitions and marginals
  4. Compile results across many different runs

Storing Graphs on ModularityBP Object

A representation of a network must be supplied at the instantiation of the modbp.ModularityBP object. Each instance can only be associated with one network. A network can be supplied in several different formats:

  • A igraph.Graph object is supplied. In this case network will be treated as single layer. This is pass in through the mlgraph parameter:

    rand_g=igraph.Graph.ErdosRenyi(n=100,p=.05)
modbp_obj=modbp.ModularityBP(mlgraph=rand_g)

  • A modbp.MultilayerGraph object can be supplied, also through the mlgraph parameter. See Multilayer Graph for more details.

  • Finally, one can pass in an array for intralayer_edges, interlayer_edges, and layer_vec, from which modbp.ModularityBP will internally construct a modbp.MultilayerGraph:

    intra_edges=np.array([[0,1],[0,2],[3,4]])
inter_edges=np.array([[2,3]])
layer_vec=[0,0,0,1,1]
modbp_obj=modbp.ModularityBP(intra_edges=intra_edges,
    inter_edges=inter_edges,
    layer_vec=layer_vec)

The graph is stored internally each modbp.ModularityBP as a modbp.MultilayerGraph and is accessible through modbp.ModularityBP.graph variable.

Running Multilayer Modularity Belief Propagation

ModularityBP.run_modbp(beta, q, niter=100, resgamma=1.0, omega=1.0, reset=False)[source]
Parameters:
  • beta – The inverse tempature parameter at which to run the modularity belief propagation algorithm. Must be specified each time BP is run.
  • q – The number of mariginals used for the run of modbp. Note that if self.use_effective is true, The final number of reported communities could be lower.
  • niter – Maximum number of iterations allowed. If self._align_communities_across_layers is true, the actual number of runs could be higher than this upper bound though at most 2*niter
  • resgamma – The resolution parameter at which to run modbp. Default is resgamma=1.0
  • omega – The coupling strength used in running multimodbp. This represent how strongly the algorithm tries to assign nodes connected by an interlayer connection to the same community.
  • reset – If true, the marginals will be rerandomized when this method is called. Otherwise the state will be maintained from previous runs if existing (assuming q hasn’t changed).
Returns:

None

Accessing partitions and marginals

Assessing Results Across Many Different Runs