[R] optimizing function over x,y

[Esmail]

Ravi Varadhan wrote:
> Look at nlminb() or optim(), in particular the option `method = "L-BFGS-B"' or the function spg() in "BB" package.
> 
> With these you can optimize over any number of variables.
> 
> Ravi. 

Hi Ravi,

Thanks for the leads, I'll take a look, though right now I have
run into problems with even the simple (?) optimize function, so
I'll first have to figure out what I'm doing wrong with it.

Best,
Esmail