This function re-roots a phylogenetic tree at an arbitrary position along an edge.
reroot(tree, node.number, position=NULL, interactive=FALSE, ...)a phylogenetic tree in "phylo" format.
number of the node descending from the target branch in tree$edge - this can also be a tip in which case the node number is the index number of the tip in tree$tip.label.
position along the target edge at which to re-root the tree. If not supplied, then the tree will be re-rooted at the node or tip.
logical value indicating whether to use interactive mode (defaults to interactive= FALSE).
arguments to be passed to plotTree for interactive=TRUE only.
A phylogenetic tree in "phylo" format.
This function had an error for rootings along edges descended from the root node for phytools<=0.2-47. This should be fixed in the present version. Now uses paste.tree, root, and splitTree internally. Earlier versions also had an error related to node labels. This should be fixed in phytools>=0.4-47.
Paradis, E., J. Claude, and K. Strimmer (2004) APE: Analyses of phylogenetics and evolution in R language. Bioinformatics, 20, 289-290.
Revell, L. J. (2012) phytools: An R package for phylogenetic comparative biology (and other things). Methods Ecol. Evol., 3, 217-223.