Manipulating modified "phylo" objects created by read.simmap().
drop.tip.simmap(): This function drops tips from modified "phylo" objects created by read.simmap(). Essentially, this function is a very simple wrapper for the drop.tip() function in "ape."
"tree" is a phylogenetic tree in modified "phylo" format;
"tip" is the name of a tip or a vector of names.
drop.tip.simmap() returns an R "phylo" object with:
"$mapped.edge" a matrix containing the time spent in each state along each edge of the tree and with the terminal taxa in "tip" removed from the tree & from "$mapped.edge."
Function written by Liam Revell 2010.
Last modified Jan. 5, 2011.