matexpo.R
## ladderize.R (2007-10-08)
## Matrix Exponential
## Copyright 2007 Emmanuel Paradis
## This file is part of the R-package `ape'.
## See the file ../COPYING for licensing issues.
matexpo <- function(x)
{
if (!is.matrix(x)) stop('"x" must be a matrix')
nr <- dim(x)[1]
if (nr != dim(x)[2]) stop('"x" must be a square matrix')
ans <- .C("mat_expo", as.double(x), as.integer(nr),
PACKAGE = "ape")[[1]]
dim(ans) <- c(nr, nr)
ans
}