This term adds one network statistic to the
model for each element in k . The \(i\) th such statistic counts the
number of distinct k[i] -instars in the network, where a
\(k\) -instar is defined to be a node \(N\) and a set of \(k\)
different nodes \(\{O_1, \dots, O_k\}\) such that the ties
\((O_j{\rightarrow}N)\) exist for \(j=1, \dots, k\) . If attr is specified
then the count is over the number of \(k\) -instars where all nodes have
the same value of the attribute. This term can only be used for directed
networks; for undirected networks see kstar . Note that
istar(1) is equal to both ostar(1) and edges .
# binary: istar(k, attr=NULL, levels=NULL)a vector of distinct integers
a vertex attribute specification (see Specifying Vertex attributes and Levels (?nodal_attributes) for details.)
TODO (See Specifying Vertex
attributes and Levels (?nodal_attributes) for details.)
ergmTerm for index of model terms currently visible to the package.
ergm:::.formatTermKeywords("ergmTerm", "istar", "subsection")