Hi! I'm using R 2.0.1 on a Sun, with mgcv library version 1.3-1. I would like to implement a new family for the function gam in mgcv (truncated Poisson family as defined in Barry & Welsh (2002), Ecological Modelling). I therefore defined a family function with all the necessary components (linkfun, linkinv, variance, etc). But then I run into problems because my link function is not a standard one, and fix.family.link() and fix.family.var() (called by gam.outer) won't work. As I understand, the purpose of these two functions is to modify families so to add a "dvar" component and a "d2link" component, necessary for the fitting. The fix I can imagine (but I didn't try yet) is to add the two extra components (dvar and d2link) when defining the new family, and to redefine the function gam.outer to avoid the use of fix.family.*. Does someone have experience with this? Would this be the end of my troubles? Thank you for your help, Eva Cantoni -- Dr Eva Cantoni phone : (+41) 22 379 8240 Econom??trie - Univ. Gen??ve fax : (+41) 22 379 8299 40, Bd du Pont d'Arve e-mail : Eva.Cantoni at metri.unige.ch CH-1211 Gen??ve 4 http://www.unige.ch/ses/metri/cantoni