Editing the "..." argument

Dear all,

I'd like tweaking the ... arguments that one user can pass in my 
function for fitting a model. More precisely, my objective function is 
(really) problematic to optimize using the "optim" function. 
Consequently, I'd like to add in the "control" argument of the latter 
function a "ndeps = rep(something, #par)" and/or "parscale = something" 
if the user has not specified it already.

Do you know a way to deal with this point?
In advance, thanks.

Mathieu

Institute of Mathematics
Ecole Polytechnique F?d?rale de Lausanne
STAT-IMA-FSB-EPFL, Station 8
CH-1015 Lausanne   Switzerland
http://stat.epfl.ch/
Tel: + 41 (0)21 693 7907