def from_equinoctial(cls, attractor, p, f, g, h, k, L, epoch=J2000):
"""Return `Orbit` from modified equinoctial elements.
Parameters
----------
attractor : Body
Main attractor.
p : ~astropy.units.Quantity
Semilatus rectum.
f : ~astropy.units.Quantity
Second modified equinoctial element.
g : ~astropy.units.Quantity
Third modified equinoctial element.
h : ~astropy.units.Quantity
Fourth modified equinoctial element.
k : ~astropy.units.Quantity
Fifth modified equinoctial element.
L : ~astropy.units.Quantity
True longitude.
epoch : ~astropy.time.Time, optional
Epoch, default to J2000.
"""
ss = equinoctial.ModifiedEquinoctialState(attractor, p, f, g, h, k, L)
return cls(ss, epoch)
def to_equinoctial(self):
"""Converts to modified equinoctial elements representation.
"""
p, f, g, h, k, L = coe2mee(
self.p.to(u.km).value, self.ecc.value,
self.inc.to(u.rad).value,
self.raan.to(u.rad).value,
self.argp.to(u.rad).value,
self.nu.to(u.rad).value)
return equinoctial.ModifiedEquinoctialState(self.attractor, p * u.km,
f * u.rad, g * u.rad,
h * u.rad, k * u.rad,
L * u.rad)
