Notebook showing an example of using reboundx in exoplanet

[ericagol]

Is your feature request related to a problem? Please describe.
I am interested in computing the jacobian of the state of a system
with respect to the initial conditions using reboundx. For example,
I would like to integrate the outer four giant planets of the solar
system. I'm planning to compare this with the NbodyGradient as
a cross-comparison of both.

Describe the solution you'd like
A Jupyter notebook or script showing an example of how to set
up and run a system in exoplanet using reboundx (fine to just
use the code which was used in implementing/debugging the
incorporation of reboundx into exoplanet).

Describe alternatives you've considered
I could just run reboundx from rebound directly, but I'm also
interested in learning how to do this from within exoplanet to,
for example, run photodynamic models.

Additional context
None at the moment!

[dfm]

Thanks Eric. Do you mainly want simple N-body integrations (as offered by REBOUND itself) or are the extra forces provided by REBOUNDx what you're looking for?

Pinging @arjunsavel to keep him in the loop.

[ericagol]

Primarily the former (so maybe there's already an example?), but I'm also interested in the extra forces for, say, integrating trappist-1 with tides.

[dfm]

No - there isn't a good example yet so this is great to have here!

[arjunsavel]

The extra forces in REBOUNDx (e.g. tides, radiation forces) aren't currently accessible via the exoplanet interface, I believe. I don't think it'd be too difficult to change this, though!