def propagate_state(r, v, t0, tf, bstar=0.21109E-4):
"""Propagates a state vector
Args:
r(1x3 numpy array): the position vector at epoch
v(1x3 numpy array): the velocity vector at epoch
t0(float): initial time (epoch)
tf(float): final time
Returns:
pos(1x3 numpy array): the position at tf
vel(1x3 numpy array): the velocity at tf
"""
kep = state_kep(r, v)
return propagate_kep(kep, t0, tf, bstar)
elif (ch == '6'):
custom(initial, ch, initial_state, time, f_time)
elif (ch == '7'):
custom(initial, ch, initial_state, time, f_time)
elif (ch == '8'):
#kep=[x0[0],x0[4],x0[5],x0[1],x0[3],mean_anomaly]
#kep=np.asarray(kep)
time = time.tt.datetime
f_time = f_time.tt.datetime
time = time.timestamp()
f_time = f_time.timestamp()
kep = state_kep(np.asarray(initial_state_r),
np.asarray(initial_state_v))
f_r, f_v = propagate_state(np.asarray(initial_state_r),
np.asarray(initial_state_v),
time,
f_time,
bstar=0.21109E-4)
#r= [float(f_v[0]),float(initial_state[1, 0]),float(initial_state[2, 0])]
f_r = np.asarray(f_r)
f_v = np.asarray(f_v)
#f_orbit= Orbit.from_vectors(Earth, r, v)
#f_orbit.plot()
print("Orbital elements:")
print(state_kep(f_r, f_v))
print("")