a positive numeric integer giving the number of tips.
rooted
a logical indicating whether the trees are rooted
(default is TRUE).
binary
a logical indicating whether the trees are bifurcating
(default is TRUE).
labeled
a logical indicating whether the trees have tips
labeled (default is TRUE).
detail
a logical indicating whether the eventual intermediate
calculations should be returned (default is FALSE). This
applies only for the multifurcating trees, and the bifurcating,
rooted, unlabeled trees (aka tree shapes).
Value
a single numeric value, or in the case where detail = TRUE is
used, a named vector or matrix.
Details
In the cases of labeled binary trees, the calculation is done directly
and a single numeric value is returned.
For multifurcating trees, and bifurcating, rooted, unlabeled trees,
the calculation is done iteratively for 1 to n tips. Thus the
user can print all the intermediate values if detail = TRUE, or
only a single value if detail = FALSE (the default).
For multifurcating trees, if detail = TRUE, a matrix is
returned with the number of tips as rows (named from 1 to
n), and the number of nodes as columns (named from 1 to
n - 1).
For bifurcating, rooted, unlabeled trees, a vector is returned with
names equal to the number of tips (from 1 to n).
The number of unlabeled trees (aka tree shapes) can be computed only
for the rooted binary cases.
Note that if an infinite value (Inf) is returned this does not
mean that there is an infinite number of trees (this cannot be if the
numnber of tips is finite), but that the calculation is beyond the
limits of the computer.
References
Felsenstein, J. (2004) Inferring phylogenies. Sunderland:
Sinauer Associates.