Compute.num_triangles()#
relationalai.std.graphs
#Compute.num_triangles(node: Producer | None = None) -> Expression
Compute the number of unique triangles in the graph.
A triangle is a set of three nodes x
, y
, and z
such that
there is an edge between x
and y
, y
and z
, and z
and x
.
If node
is not None
, the number of unique triangles that node
is part of is computed.
Must be called in a rule or query context.
Supported Graph Types#
Graph Type | Supported | Notes |
---|---|---|
Directed | Yes | |
Undirected | Yes | |
Weighted | Yes | Weights are ignored. |
Unweighted | Yes |
Parameters#
Name | Type | Description |
---|---|---|
node | Producer or None | A node in the graph. If not None , the number of unique triangles that node is part of is computed. Otherwise, the total number of unique triangles in the graph is computed. Default is None . |
Returns#
Returns an Expression object that produces
the number of unique triangles in the graph as an integer value, if node
is None
,
or the number of unique triangles that node
is part of as an integer value, if node
is not None
.
Example#
Use .num_triangles()
to compute the number of unique triangles in a graph.
You access the .num_triangles()
method from a Graph
object’s
.compute
attribute:
#import relationalai as rai
from relationalai.std import alias
from relationalai.std.graphs import Graph
# Create a model named "socialNetwork" with a Person type.
model = rai.Model("socialNetwork")
Person = model.Type("Person")
# Add some people to the model and connect them with a multi-valued `follows` property.
with model.rule():
alice = Person.add(name="Alice")
bob = Person.add(name="Bob")
charlie = Person.add(name="Charlie")
diana = Person.add(name="Diana")
alice.follows.add(bob)
bob.follows.add(charlie)
charlie.follows.extend([alice, diana])
# Create a directed graph with Person nodes and edges between followers.
# Note that graphs are directed by default.
graph = Graph(model)
graph.Node.extend(Person)
graph.Edge.extend(Person.follows)
# Compute the number of unique triangles in the graph.
with model.query() as select:
num_triangles = graph.compute.num_triangles()
response = select(alias(num_triangles, "num_triangles"))
print(response.results)
# Output:
# num_triangles
# 0 1
# Compute the number of unique triangles that each node is part of.
with model.query() as select:
person = Person()
num_triangles = graph.compute.num_triangles(person)
response = select(person.name, alias(num_triangles, "num_triangles"))
print(response.results)
# Output:
# name num_triangles
# 0 Alice 1
# 1 Bob 1
# 2 Charlie 1
# 3 Diana 0