def test_vallado62(self):
alt_i = 191.34411 # km
alt_b = 503873 # km
alt_f = 376310.0 # km
k = k_earth.to(units.km ** 3 / units.s ** 2).value
R = R_earth.to(units.km).value
expected_dv = 3.904057 # km/s
expected_t_trans = 593.919803 # h
r_i = R + alt_i
r_b = R + alt_b
r_f = R + alt_f
dva, dvb, dvc, _, _, t_trans1, t_trans2 = bielliptic(k, r_i, r_b, r_f)
dv = abs(dva) + abs(dvb) + abs(dvc)
t_trans = t_trans1 + t_trans2
assert_almost_equal(dv, expected_dv, decimal=2)
assert_almost_equal(t_trans / 3600, expected_t_trans, decimal=0)
v_i = 7.905 # km/s, immaterial
R = np.linspace(2, 75, num=1000)
Rstar = [15.58, 40, 60, 100, 200, np.inf]
hohmann_data = np.zeros_like(R)
bielliptic_data = np.zeros((len(R), len(Rstar)))
r_i = k_Earth / v_i ** 2
for ii, r in enumerate(R):
r_f = r * r_i
dva, dvb, _, _ = twobody.hohmann(k_Earth, r_i, r_f)
hohmann_data[ii] = (abs(dva) + abs(dvb)) / v_i
for jj, rstar in enumerate(Rstar):
r_b = rstar * r_i
dva, dvb, dvc, *_ = twobody.bielliptic(k_Earth, r_i, r_b, r_f)
bielliptic_data[ii, jj] = (abs(dva) + abs(dvb) + abs(dvc)) / v_i
idx_max = np.argmax(hohmann_data)
hohmann_max = hohmann_data[idx_max]
ylims = (0.35, 0.6)
fig, ax = plt.subplots()
l, = ax.plot(R, hohmann_data, lw=2)
for jj in range(len(Rstar)):
ax.plot(R, bielliptic_data[:, jj], color=l.get_color())
ax.vlines([11.94, R[idx_max]], *ylims, color='0.6')
if ZOOM: