def test_velocity():
t_tensor = tt.dvector()
t = np.linspace(0, 100, 1000)
m_planet = 0.1
m_star = 1.3
orbit = KeplerianOrbit(
m_star=m_star,
r_star=1.0,
t0=0.5,
period=100.0,
ecc=0.1,
omega=0.5,
Omega=1.0,
incl=0.25 * np.pi,
m_planet=m_planet,
)
star_pos = orbit.get_star_position(t_tensor)
star_vel = theano.function([], orbit.get_star_velocity(t))()
star_vel_expect = np.empty_like(star_vel)
for i in range(3):
g = theano.grad(tt.sum(star_pos[i]), t_tensor)
star_vel_expect[i] = theano.function([t_tensor], g)(t)
assert np.allclose(star_vel, star_vel_expect)
planet_pos = orbit.get_planet_position(t_tensor)
planet_vel = theano.function([], orbit.get_planet_velocity(t))()
planet_vel_expect = np.empty_like(planet_vel)
for i in range(3):
g = theano.grad(tt.sum(planet_pos[i]), t_tensor)
planet_vel_expect[i] = theano.function([t_tensor], g)(t)
assert np.allclose(planet_vel, planet_vel_expect)
pos = orbit.get_relative_position(t_tensor)
vel = np.array(theano.function([], orbit.get_relative_velocity(t))())
vel_expect = np.empty_like(vel)
for i in range(3):
g = theano.grad(tt.sum(pos[i]), t_tensor)
vel_expect[i] = theano.function([t_tensor], g)(t)
assert np.allclose(vel, vel_expect)
def test_acceleration():
t_tensor = tt.dvector()
t = np.linspace(0, 100, 1000)
m_planet = 0.1
m_star = 1.3
orbit = KeplerianOrbit(
m_star=m_star,
r_star=1.0,
t0=0.5,
period=100.0,
ecc=0.1,
omega=0.5,
incl=0.25 * np.pi,
m_planet=m_planet,
)
star_vel = orbit.get_star_velocity(t_tensor)
star_acc = theano.function([], orbit.get_star_acceleration(t))()
star_acc_expect = np.empty_like(star_acc)
for i in range(3):
g = theano.grad(tt.sum(star_vel[i]), t_tensor)
star_acc_expect[i] = theano.function([t_tensor], g)(t)
utt.assert_allclose(star_acc, star_acc_expect)
planet_vel = orbit.get_planet_velocity(t_tensor)
planet_acc = theano.function([], orbit.get_planet_acceleration(t))()
planet_acc_expect = np.empty_like(planet_acc)
for i in range(3):
g = theano.grad(tt.sum(planet_vel[i]), t_tensor)
planet_acc_expect[i] = theano.function([t_tensor], g)(t)
utt.assert_allclose(planet_acc, planet_acc_expect)
vel = orbit.get_relative_velocity(t_tensor)
acc = theano.function([], orbit.get_relative_acceleration(t))()
acc_expect = np.empty_like(acc)
for i in range(3):
g = theano.grad(tt.sum(vel[i]), t_tensor)
acc_expect[i] = theano.function([t_tensor], g)(t)
utt.assert_allclose(acc, acc_expect)