[R] NUMERIC DERIVATE

[Thomas W Blackwell]

On Wed, 17 Dec 2003, Savano S. Pereira wrote:

> UseRs,
>
> I used the optim function
>
> valor.optim <- optim(c(1,1,1),logexp1,method
> ="BFGS",control=list(fnscale=-1),hessian=T);
>
> and I want to calculate the derivates,  [ ... snip ... ]
>
> but I found,  [ ... snip ... ]
>
> The derivates are zero. Why?

Do you suppose it could have something to do with the
condition for finding an optimum ?

-  tom blackwell  -  u michigan medical school  -  ann arbor  -