[R] psigamma derivative

[anamaria at ufc.br]

Hello,

I am trying to find a hessian matrix  that
involves log(gamma(1/p)) second derivative, p being one of the parameters
of the function. I am using a function "deriv" with the hessian=TRUE
option, but psigamma is not on the list of derivative functions.
I know that it is possible to use 'psigamma(p,deriv)', but it doesn't work
with 1/p. Does anybody can help with this?

Thanks,
Ana Maria