flintlib
Describe how to obtain derivative of zeta functions
Currently https://arblib.org/arb.html?highlight=zeta#c.arb_zeta only says that one should use arb_poly_zeta_series to obtain the derivative of Riemann/Hurwitz zeta function, but is not described in either place.
Would it be possible to add a description on how to obtain these?
Normally you construct the polynomial f = s+x, evaluate zeta(f), and read off the coefficients.
The interfaces for derivatives could use a bit of work. First, most functions ought to have _jet versions (we have them in a few places). Second, a bunch of function should have _derivative versions that return just the nth derivative. This is convenient since you don't need to a temporary array, and in some cases the nth derivative can be computed faster than the first n derivatives together.
