The linear network L
must be an acyclic graph (i.e. must not contain any loops) so that it
can be interpreted as a tree.
The result of f <- branchlabelfun(L, root)
is
a function f
which gives,
for each location on the linear network L
,
the tree branch label at that location.
Tree branch labels are explained in treebranchlabels
.
The result f
also belongs to the class "linfun"
.
It can be called using several different kinds of data,
as explained in the help for linfun
.
The values of the function are character strings.