http://franz.com/ns/allegrograph/4.11/sna/communityLeiden

Magic property sna:communityLeiden implements Leiden Community Detection algorithm, it takes a list of keyword arguments:

Name Type Default Optional Description
generator Resource nil yes A defined SNA generator
actor Resource nil yes A start node (actor) for traversing the RDF graph by the generator
depth Numeric or nil nil yes The depth for making an ego group. Must not be nil if generator is non- nil. See note 1 following the table.
selector Resource nil yes A defined SNA selector
resolution Numeric 1.0 yes A parameter that is used when computing the modularity
beta Numeric 0.01 yes A parameter that controls the randomness while breaking a community into smaller ones
iterations Numeric -1 yes A parameter that controls the total iterations. -1 means iterate until modularity cannot be improved further.
seed Numeric or nil nil yes A parameter that sets the random generator’s seed to have re-producible communities

Note 1 The depth argument can only be nil when the generator argument is not specified or nil. Otherwise, depth must be a non-negative integer and will be used along with the generator and actor for constructing an SNA ego group.

Note that, users must supply either a generator or a selector. When the computation is done, it returns detected communities as ego groups (fully compatible with other operations e.g. sna:groupDegreeCentrality, and each group will be assigned with an integer community ID. For example, the query below not only runs a leiden cummunity detection, but also inserts new triples by utilizing the returned ego groups as well as IDs: 

PREFIX sna: <http://franz.com/ns/allegrograph/4.11/sna/>  
PREFIX : <http://franz.com/ns/keyword#>  
 
PREFIX ex: <ex://#>  
 
INSERT {  
  ?communityId rdf:type sna:Community .  
  ?actor sna:communityMember ?communityId .  
}  
WHERE {  
  (?group ?groupId) sna:communityLeiden (:selector ex:someSelector :seed 1000) .  
  BIND (IRI(concat("ex://#Community-", str(?groupId) )) AS ?communityId) .  
  ?actor sna:members ?group .  
}

Notes

The following namespace abbreviations are used:

The SPARQL magic properties reference has additional information on using AllegroGraph magic properties and functions.