Given a graph and a node, determine if the node is a result of combinations of multiple codes.
is_combined(graph, node, compare_node = NULL)
TRUE
if the node is a combination of two or more nodes,
otherwise FALSE
.
A graph generated by klass_graph
.
A node as returned by klass_node
or
V
.
Optional. A node to compare node
with when
determining whether node
is combined. See details.
The function will attempt to reconcile nodes that have split and then later merged again when evaluating a node's combinedness.
If compare_node == NULL
, a node is considered to be combined if more
than one node that does not itself have a parent (i.e. codes at the start
of a sequence of changes) contribute to node
.
If compare_node != NULL
, a node is considered to be combined if any
node that is not an ancestor of compare_node
contributes to
node
, i.e. all paths from node
to the parents of node
pass through compare_node
.