-## is.ultrametric.R (2009-03-09)
+## is.ultrametric.R (2009-05-10)
## Test if a Tree is Ultrametric
is.ultrametric <- function(phy, tol = .Machine$double.eps^0.5)
{
- if (class(phy) != "phylo")
+ if (!inherits(phy, "phylo"))
stop('object "phy" is not of class "phylo".')
if (is.null(phy$edge.length))
stop("the tree has no branch lengths.")