[R] Any numeric differentiation routine in R for boundary points?

[Gabor Grothendieck]

Reparameterize to

f(x, y) = sqrt(x*x) * exp(y*y)

On Jan 26, 2008 1:11 PM, roger chan <rogerchan2006 at gmail.com> wrote:
>
> Hi, I have a scalar valued function with several variables. One of the
> variables is restricted to be non-negative. For example,
> f(x,y)=sqrt(x)*exp(y), then x should be non-negative. I need the
> gradient and hessian for some vector (0,y), i.e., I need the gradient and
> hessian at the boudary of parameter space.
>
> The "numderiv" package does not work, even for f(x)=sqrt(x), if you
> do "genD(f,x=0)", warning message comes out.
>
> I need the one sided derivatives.
>
> Thanks if you could provide some help.
> --
> View this message in context: http://www.nabble.com/Any-numeric-differentiation-routine-in-R-for-boundary-points--tp15110811p15110811.html
> Sent from the R help mailing list archive at Nabble.com.
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>