The code hard codes Jacobi coordinates (with input_flag=0). The code should support other valid values of this flag, so add this in.
Original report:
I was doing some testing with TTVFast today, and I realized that you have hard-coded ttvfast-python to use Jacobi coordinates (input_flag=0). I usually work in astrocentric coordinates, so I modified my own version of init.py to allow myself to set the input_flag to a non-zero value. You might want to make this change in the distributed version as well!
Example updated code, in __init__.py:
# -*- coding: utf-8 -*-
"Fast TTV computation"
__all__ = ['ttvfast']
from ._ttvfast import _ttvfast as _ttvfast_fn
from . import models
def ttvfast(planets, stellar_mass, time, dt, total, rv_times=None, input_flag = 0):
'''
Run the TTV fast function. See https://github.com/kdeck/TTVFast.
Program arguments:
* planets: list of `models.Planet` instances
* stellar_mass: stellar mass (solar masses)
* time: start point for integration (days)
* dt: time step for the integration (days)
* total: end point for integration (days)
* rv_times: rv measurement times
* input_flag: IC system [0=Jacobi, 1=astrocentric_elements, 2=astrocentric_cartesian]
'''
params = models.planets_to_params(stellar_mass, planets)
n_plan = len(planets)
len_rv = len(rv_times) if rv_times is not None else 0
positions, rv = _ttvfast_fn(params, dt, time, total, n_plan, input_flag, len_rv, rv_times)
return {'positions': positions, 'rv': rv}
__all__ = ['ttvfast']
The code hard codes Jacobi coordinates (with
input_flag=0). The code should support other valid values of this flag, so add this in.Original report:
Example updated code, in
__init__.py: