For specifying the initial parameters of the system, we need to specify the masses and the initial coordinates. For the initial conditions, the masses are specified before the orbital elements. But, for the Jacobian, we propagate a square matrix which contains derivatives with respect to a flattened set of coordinates, in which the masses come after the cartesian coordinates. This change of the order of the masses and coordinates is confusing for users and developers, and we would like to change this so that the order is consistent.
For specifying the initial parameters of the system, we need to specify the masses and the initial coordinates. For the initial conditions, the masses are specified before the orbital elements. But, for the Jacobian, we propagate a square matrix which contains derivatives with respect to a flattened set of coordinates, in which the masses come after the cartesian coordinates. This change of the order of the masses and coordinates is confusing for users and developers, and we would like to change this so that the order is consistent.