genAldousBetaTree {poweRbal} | R Documentation |
Generation of rooted binary trees under Aldous' beta splitting model
Description
genAldousBetaTree
- Generates a rooted binary tree in
phylo
format with the given number of n
leaves under the
Aldous beta model.
The Aldous beta model is not a rate-based incremental evolutionary (tree)
construction and thus cannot generate edge lengths, only a topology.
Instead, the Aldous beta model works as follows: The idea is to start with
the root and the set of its descendant leaves, i.e., all n
leaves.
Then, this set is partitioned into two subsets according to a density
function dependent on the parameter beta
.
The two resulting subsets contain the leaves of the two maximal pending
subtrees of the root, respectively. The same procedure is then applied to the
root's children and their respective subsets, and so forth.
Usage
genAldousBetaTree(n, BETA)
Arguments
n |
Integer value that specifies the desired number of leaves, i.e.,
vertices with in-degree 1 and out-degree 0. |
BETA |
Numeric value >=-2 which specifies how the leaf sets
are partitioned. For certain choices of
|
Value
genAldousBetaTree
A single tree of class phylo
is
returned.
References
D. Aldous. Probability Distributions on Cladograms. In Random Discrete Structures, pages 1–18. Springer New York, 1996.
Examples
genAldousBetaTree(n = 5, BETA = 1)