By default, this term adds one statistic to the model equal to the number of triangles
in the network. For an undirected network, a triangle is defined to be any
set \(\{(i,j), (j,k), (k,i)\}\) of three edges. For a directed network, a
triangle is defined as any set of three edges \((i{\rightarrow}j)\)
and \((j{\rightarrow}k)\) and either \((k{\rightarrow}i)\)
or \((k{\leftarrow}i)\) . The former case is called a "transitive
triple" and the latter is called a "cyclic triple", so in the case of a
directed network, triangle
equals ttriple
plus ctriple
--- thus at most two of these three terms can be in a model.
# binary: triangle(attr=NULL, diff=FALSE, levels=NULL)# binary: triangles(attr=NULL, diff=FALSE, levels=NULL)
quantitative attribute (see Specifying Vertex attributes and Levels (?nodal_attributes
) for details.) If attr
is specified and diff
is FALSE
,
then the count is restricted to those triples of nodes with
equal values of the vertex attribute specified by attr
. If attr
is specified and diff
is TRUE
,
then one statistic is added for each value of attr
,
equal to the number of triangles where all three nodes have that value of the attribute.
add one statistic for each value specified if diff
is TRUE
. (See Specifying Vertex
attributes and Levels (?nodal_attributes
) for details.)
ergmTerm
for index of model terms currently visible to the package.
ergm:::.formatTermKeywords("ergmTerm", "triangle", "subsection")