Finite difference operator

[Juan Pablo Carbajal]

Hi,
I have the impression that at some point I found a function of Octave
that would provide the finite difference operator for given order and
number of points. Or maybe it was a function to calculate the finite
difference coefficients given order and points...

Can anyone help me find these functions again? Or maybe better any
recommendations of functions to use to estimate high order derivatives
using finite differences using finite but arbitrary large number of
points?

Thanks