An argument flat has been added to profileCI() to deal with cases where one or both of the limits is (minus or plus) infinity because the profile log-likelihood fails to drop below the level that defines the confidence interval.
Arguments lb and ub have been added to profileCI() to place respective lower and upper bounds on the interval over which profiling takes place.
A logLikFn method has been added for objects inheriting from class nls and an example added to the documentation of profileCI().
Bug fixes and minor improvements
The argument optim_args actually works now! Thank you to Jakob Madsen (#1).
An explanation of the creation of coef and vcov methods has been added to the description of object in the profileCI() documentation.
Arguments to the user-supplied log-likelihood function are extracted explicitly to simplify the code and avoid potential argument matching issues.