def from_vectors(cls,
attractor,
r,
v,
epoch=J2000,
plane=Planes.EARTH_EQUATOR):
"""Return `Orbit` from position and velocity vectors.
Parameters
----------
attractor : Body
Main attractor.
r : ~astropy.units.Quantity
Position vector wrt attractor center.
v : ~astropy.units.Quantity
Velocity vector.
epoch : ~astropy.time.Time, optional
Epoch, default to J2000.
plane : ~poliastro.frames.Planes
Fundamental plane of the frame.
"""
assert np.any(r.value), "Position vector must be non zero"
ss = rv.RVState(attractor, r, v)
return cls(ss, epoch, plane)
def to_vectors(self):
"""Converts to position and velocity vector representation.
"""
r, v = coe2rv(
self.attractor.k.to(u.km**3 / u.s**2).value,
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 rv.RVState(self.attractor, r * u.km, v * u.km / u.s)
def from_vectors(cls, attractor, r, v, epoch=J2000):
"""Return `Orbit` from position and velocity vectors.
Parameters
----------
attractor : Body
Main attractor.
r : ~astropy.units.Quantity
Position vector wrt attractor center.
v : ~astropy.units.Quantity
Velocity vector.
epoch : ~astropy.time.Time, optional
Epoch, default to J2000.
"""
assert np.any(r.value), "Position vector must be non zero"
ss = rv.RVState(attractor, r, v)
return cls(ss, epoch)
