I am working on fitting a model using the nlme package in R.
y is a saturating function of
x, similar in form to a michaelis-menten function where
y = Vm*x / (K+x)
I would like to parameterize this model using my data set, and control for a third variable,
z, as a random effect. I cannot seem to implement this so far in the nlme framework. Any tips on how to do so, or how to do so in a different package, would be greatly appreciated.