Force a block-diagonal structure (and its bipartite analogue) on
the network. Only dyads \((i,j)\) for which
attr(i)==attr(j) can have edges.
Note that the current implementation requires that blocks be contiguous for unipartite graphs, and for bipartite graphs, they must be contiguous within a partition and must have the same ordering in both partitions. (They do not, however, require that all blocks be represented in both partitions, but those that overlap must have the same order.)
If multiple block-diagonal constraints are given, or if
attr is a vector with multiple attribute names, blocks
will be constructed on all attributes matching.
# blockdiag(attr)a vertex attribute specification (see Specifying Vertex attributes and Levels (?nodal_attributes) for details.)
ergmConstraint for index of constraints and hints currently visible to the package.
ergm:::.formatTermKeywords("ergmConstraint", "blockdiag", "subsection")