| b2 {treestats} | R Documentation |
B2 metric
Description
Balance metric that uses the Shannon-Wiener statistic of information content. The b2 measure is given by the sum over the depths of all tips, divided by 2^depth: sum Ni / 2^Ni. Although also defined on non-binary trees, the treestats package only provides code for binary trees.
Usage
b2(phy, normalization = "none")
Arguments
phy |
phylo object or ltable |
normalization |
"none" or "yule", when "yule" is chosen, the statistic is divided by the Yule expectation, following from theorem 3.7 in Bienvenu 2020. |
Value
Maximum depth (in number of edges)
References
K.-T. Shao and R. R. Sokal. Tree Balance. Systematic Zoology, 39(3):266, 1990. doi: 10.2307/2992186.
Bienvenu, François, Gabriel Cardona, and Celine Scornavacca. "Revisiting Shao and Sokal’s $$ B_2 $$ B 2 index of phylogenetic balance." Journal of Mathematical Biology 83.5 (2021): 1-43.