This function takes a tree and node or tip number of label and returns the number or label of the sister or sisters to that node or tip.
getSisters(tree, node, mode=c("number","label"))
object of class "phylo"
.
a node number, tip number, node label, or tip label.
an optional string indicating whether to return the node or tip number(s) or the node or tip label(s), if applicable.
If mode="number"
this function returns an integer or vector containing the node number of numbers of the sister node or tip. If mode="label"
then this function returns a list containing up to two vectors: one for the node numbers of labels of sister nodes (if applicable); and the other containing the tip labels of the sister tips.
Revell, L. J. (2012) phytools: An R package for phylogenetic comparative biology (and other things). Methods Ecol. Evol., 3, 217-223.