[Help-gsl] how to make dense output for rk8pd

[Kirill Igumenshchev]

Hi,

I've been using Numerical Recipes for ODE. I really like an option of
dense output.

I cannot figure out a way to get it in GSL.

the dense output is described in Num Rec 3 in 17.2.2
(http://www.nrbook.com/nr3/)

the advantage of rk8 with dense output in NR is that interpolation
uses derivatives from rk8

i wanted to do a similar thing in GSL.
gsl_odeiv_step_apply outputs a derivative but i don't see a way to use
that derivative in interpolation.

is there a way to use known derivatives in interpolation or does
anyone have an idea how to get a dense output?

--Kirill