Compare edges in two tpdag objects or two tskeleton objects. Note that they should be based on the same variables. Only edge absence/presence is compared, not edge orientation.
compare(x, y = NULL)A list with entries: $nedges1 (the number of
edges in the first object), $nedges2 (the number of edges
in the second object), $psi1 (the test significance level
of the first object), $psi2 (the test significance level of
the second object), $nadded (the number of additional edges in
object 2, relative to object 1), and nremoved (the number of
absent edges in object 2, relative to object 1).
First object
Second object (optional)