[R] How to obtain final gradient estimation from optim

[Stéphane Luchini]

I use optim to compute maximum likelihood estimations without giving an 
analytical gradient to optim. However, I would like to 
get an output of the final numerical gradient vector and the final matrix of 
contributions to the gradient. But I did not 
find any mention of this kind of output in help pages. Does anyone know how to 
do that ?

Stephane Luchini
GREQAM
Marseille, France