Currently a restricted-feature-set version of
make.mkn, but including gradient (first derivative)
information along with the likelihood. Currently lacks several
features of the full mkn model: no support for missing trait
data, no support for different root treatments, no optimised 2-state
method.
In the future, this will roll back into make.mkn, so do
not use or depend on this!
ape k.make.mkn, which is more general, and from which this
inherits support methods for ML and MCMC inference.