Given a design and formula, fit the zero inflated regression, storing the fits in slots
fitC
and fitD
fit(object, response, ...)
# S4 method for LMERlike,missing
fit(object, response, silent = TRUE, ...)
inheriting from LMlike
a vector, same length as the design, or if missing then use the current response
currently ignored
mute some warnings emitted from the underlying modeling functions
LMlike or subclass