Numerical evaluation of zeta and psi functions



On 12/30/06, Andrej Vodopivec <andrej.vodopivec at gmail.com> wrote:
> I also think that maxima is using incorrect reflection formula for
> negative values of z:
>
> psi[n](z) = (-1)^n*psi[n](-z) + (-1)^n*diff(cot(-%pi*z), z, n)
>
> I think this should be
>
> psi[n](z) = (-1)^n*psi[n](1-z)+(-1)^n*diff(cot(%pi*(1-z)), z, n)

Sorry, this should be

psi[n](z) = (-1)^n*psi[n](1-z)+(-1)^n*%pi*diff(cot(%pi*(1-z)), z, n)

the factor %pi is missing in symbolic simplification code. Numeric
code has %pi but has z instead of 1-z on the right side.

Andrej