def test_compare_calculate_trajectory_iterator_cartesians(
pos_vec, vel_vec, q, M, a, Q, el, ss):
cl1 = KerrNewman.from_cartesian(pos_vec, vel_vec, q, 0 * u.s, M, a, Q)
cl2 = KerrNewman.from_cartesian(pos_vec, vel_vec, q, 0 * u.s, M, a, Q)
ans1 = cl1.calculate_trajectory(end_lambda=el,
OdeMethodKwargs={"stepsize": ss},
return_cartesian=True)[1]
it = cl2.calculate_trajectory_iterator(OdeMethodKwargs={"stepsize": ss},
return_cartesian=True)
ans2 = list()
for _, val in zip(range(20), it):
ans2.append(val[1])
ans2 = np.array(ans2)
print(ans1)
assert_allclose(ans1[:20], ans2)
def test_calculate_trajectory0():
# Based on the revolution of earth around sun
# Data from https://en.wikipedia.org/wiki/Earth%27s_orbit
# Initialialized with cartesian coordinates
# Function returning cartesian coordinates
M = 1.989e30 * u.kg
q = 0 * u.C / u.kg
Q = 0 * u.C
distance_at_perihelion = 147.10e6 * u.km
speed_at_perihelion = 30.29 * u.km / u.s
cart_obj = CartesianDifferential(
distance_at_perihelion / np.sqrt(2),
distance_at_perihelion / np.sqrt(2),
0 * u.km,
-1 * speed_at_perihelion / np.sqrt(2),
speed_at_perihelion / np.sqrt(2),
0 * u.km / u.h,
)
a = 0 * u.m
end_lambda = ((1 * u.year).to(u.s)).value
cl = KerrNewman.from_cartesian(cart_obj, q, M, a, Q)
ans = cl.calculate_trajectory(
start_lambda=0.0,
end_lambda=end_lambda,
return_cartesian=True,
OdeMethodKwargs={"stepsize": end_lambda / 1.5e3},
)[1]
# velocity should be 29.29 km/s at apehelion(where r is max)
R = np.sqrt(ans[:, 1]**2 + ans[:, 2]**2 + ans[:, 3]**2)
i = np.argmax(R) # index whre radial distance is max
v_apehelion = ((np.sqrt(ans[i, 5]**2 + ans[i, 6]**2 + ans[i, 7]**2) *
(u.m / u.s)).to(u.km / u.s)).value
assert_allclose(v_apehelion, 29.29, rtol=0.01)
def test_compare_calculate_trajectory_iterator_cartesians(test_input):
cart_obj = CartesianDifferential(
1000000 * u.m,
1000000 * u.m,
20.5 * u.m,
10000 * u.m / u.s,
10000 * u.m / u.s,
-30 * u.m / u.s,
)
M = 2e24 * u.kg
q, a, Q, el, ss = test_input
cl1 = KerrNewman.from_cartesian(cart_obj, q, M, a, Q)
cl2 = KerrNewman.from_cartesian(cart_obj, q, M, a, Q)
ans1 = cl1.calculate_trajectory(end_lambda=el,
OdeMethodKwargs={"stepsize": ss},
return_cartesian=True)[1]
it = cl2.calculate_trajectory_iterator(OdeMethodKwargs={"stepsize": ss},
return_cartesian=True)
ans2 = list()
for _, val in zip(range(20), it):
ans2.append(val[1])
ans2 = np.array(ans2)
print(ans1)
assert_allclose(ans1[:20], ans2)