avgLeafDepI {treebalance} | R Documentation |
Calculation of the average leaf depth index for rooted trees
Description
This function calculates the average leaf depth for a given
rooted tree
. The tree must not necessarily be binary.
is
defined as
in which denotes the number of leaves in
,
denotes the set of inner nodes of
and
denotes the number of leaves in the pending subtree that is rooted
at the inner node
. Note that
can also be
computed from the Sackin index
as
.
The average leaf depth is an imbalance index.
For the function returns
and a warning.
For details on the average leaf depth, see also Chapter 6 in "Tree balance indices: a comprehensive survey" (https://doi.org/10.1007/978-3-031-39800-1_6).
Usage
avgLeafDepI(tree)
Arguments
tree |
A rooted tree in phylo format. |
Value
avgLeafDepI
returns the average leaf depth of the given tree.
Author(s)
Luise Kuehn
References
M. J. Sackin. "Good" and "Bad" Phenograms. Systematic Biology, 21(2):225-226, 1972. doi: 10.1093/sysbio/21.2.225.
K.-T. Shao and R. R. Sokal. Tree Balance. Systematic Zoology, 39(3):266, 1990.
doi: 10.2307/2992186.
Examples
tree <- ape::read.tree(text="((((,),),(,)),(((,),),(,)));")
avgLeafDepI(tree)