def test_from_ephem_raises_warning_if_time_is_not_tdb_with_proper_time(recwarn):
body = Earth
epoch = Time("2017-09-29 07:31:26", scale="utc")
expected_epoch_string = "2017-09-29 07:32:35.182" # epoch.tdb.value
Orbit.from_body_ephem(body, epoch)
w = recwarn.pop(TimeScaleWarning)
assert expected_epoch_string in str(w.message)
def test_from_ephem_raises_warning_if_time_is_not_tdb_with_proper_time(recwarn):
body = Earth
epoch = Time("2017-09-29 07:31:26", scale="utc")
expected_epoch_string = "2017-09-29 07:32:35.182" # epoch.tdb.value
Orbit.from_body_ephem(body, epoch)
w = recwarn.pop(TimeScaleWarning)
assert expected_epoch_string in str(w.message)
def test_plot_trajectory_sets_label():
op = OrbitPlotter()
earth = Orbit.from_body_ephem(Earth)
mars = Orbit.from_body_ephem(Mars)
trajectory = earth.sample()
op.plot(mars, label="Mars")
op.plot_trajectory(trajectory, label="Earth")
legend = plt.gca().get_legend()
assert legend.get_texts()[1].get_text() == "Earth"
def test_plot_trajectory_sets_label():
op = OrbitPlotter()
earth = Orbit.from_body_ephem(Earth)
mars = Orbit.from_body_ephem(Mars)
trajectory = earth.sample()
op.plot(mars, label="Mars")
op.plot_trajectory(trajectory, label="Earth")
legend = plt.gca().get_legend()
assert legend.get_texts()[1].get_text() == "Earth"
def test_redraw_keeps_trajectories():
# See https://github.com/poliastro/poliastro/issues/518
op = StaticOrbitPlotter()
earth = Orbit.from_body_ephem(Earth)
mars = Orbit.from_body_ephem(Mars)
trajectory = earth.sample()
op.plot(mars, label="Mars")
op.plot_trajectory(trajectory, label="Earth")
assert len(op.trajectories) == 2
op.set_frame(*mars.pqw())
assert len(op.trajectories) == 2
def plot_solar_system(outer=True, epoch=None):
"""
Plots the whole solar system in one single call.
.. versionadded:: 0.9.0
Parameters
------------
outer : bool, optional
Whether to print the outer Solar System, default to True.
epoch: ~astropy.time.Time, optional
Epoch value of the plot, default to J2000.
"""
bodies = [Mercury, Venus, Earth, Mars]
if outer:
bodies.extend([Jupiter, Saturn, Uranus, Neptune])
op = OrbitPlotter()
for body in bodies:
orb = Orbit.from_body_ephem(body, epoch)
op.plot(orb, label=str(body))
# Sets frame to the orbit of the Earth by default
# TODO: Wait until https://github.com/poliastro/poliastro/issues/316
# op.set_frame(*Orbit.from_body_ephem(Earth, epoch).pqw())
return op
def plot_solar_system(outer=True, epoch=None):
"""
Plots the whole solar system in one single call.
.. versionadded:: 0.9.0
Parameters
------------
outer : bool, optional
Whether to print the outer Solar System, default to True.
epoch: ~astropy.time.Time, optional
Epoch value of the plot, default to J2000.
"""
bodies = [Mercury, Venus, Earth, Mars]
if outer:
bodies.extend([Jupiter, Saturn, Uranus, Neptune])
op = OrbitPlotter()
for body in bodies:
orb = Orbit.from_body_ephem(body, epoch)
op.plot(orb, label=str(body))
# Sets frame to the orbit of the Earth by default
# TODO: Wait until https://github.com/poliastro/poliastro/issues/316
# op.set_frame(*Orbit.from_body_ephem(Earth, epoch).pqw())
return op
def hill_radius(body, a=None, e=None):
"""Approximated radius of the Hill Sphere of Influence (SOI) for a body.
Parameters
----------
body : `~poliastro.bodies.Body`
Astronomical body which the SOI's radius is computed for.
a : float, optional
Semimajor axis of the body's orbit, default to None (will be computed from ephemerides).
e : float, optional
Eccentricity of the body's orbit, default to 0 (will be computed from ephemerides).
Returns
-------
astropy.units.quantity.Quantity
Approximated radius of the Sphere of Influence (SOI) [m]
"""
# Compute semimajor and eccentricity axis at epoch J2000 for the body if it was not
# introduced by the user
if a is None or e is None:
# https://github.com/poliastro/poliastro/pull/679#issuecomment-503902597
from poliastro.twobody.orbit import Orbit
ss = Orbit.from_body_ephem(body, J2000_TDB)
a = a if a is not None else ss.a
e = e if e is not None else ss.ecc
mass_ratio = body.k / (3 * body.parent.k)
r_SOI = a * (1 - e) * (mass_ratio**(1 / 3))
return r_SOI.decompose()
def laplace_radius(body, a=None):
"""Approximated radius of the Laplace Sphere of Influence (SOI) for a body.
Parameters
----------
body : `~poliastro.bodies.Body`
Astronomical body which the SOI's radius is computed for.
a : float, optional
Semimajor axis of the body's orbit, default to None (will be computed from ephemerides).
Returns
-------
astropy.units.quantity.Quantity
Approximated radius of the Sphere of Influence (SOI) [m]
"""
# Compute semimajor axis at epoch J2000 for the body if it was not
# introduced by the user
if a is None:
# https://github.com/poliastro/poliastro/pull/679#issuecomment-503902597
from poliastro.twobody.orbit import Orbit
a = Orbit.from_body_ephem(body, J2000_TDB).a
r_SOI = a * (body.k / body.parent.k)**(2 / 5)
return r_SOI.decompose()
def test_show_calls_prepare_plot(mock_prepare_plot, mock_iplot):
m = OrbitPlotter2D()
earth = Orbit.from_body_ephem(Earth)
m.plot(orbit=earth, label="Obj")
m.show()
assert mock_iplot.call_count == 1
mock_prepare_plot.assert_called_once_with()
def test_set_frame_plots_same_colors():
op = plot_solar_system()
jupiter = Orbit.from_body_ephem(Jupiter)
op.plot(jupiter)
colors1 = [orb[2] for orb in op._orbits]
op.set_frame(*jupiter.pqw())
colors2 = [orb[2] for orb in op._orbits]
assert colors1 == colors2
def test_show_calls_prepare_plot(plotter_class):
with mock.patch.object(plotter_class, "_prepare_plot") as mock_prepare_plot:
m = plotter_class()
earth = Orbit.from_body_ephem(Earth)
m.plot(orbit=earth, label="Object")
m.show()
mock_prepare_plot.assert_called_with()
def test_set_frame_plots_same_colors():
# TODO: Review
op = StaticOrbitPlotter()
jupiter = Orbit.from_body_ephem(Jupiter)
op.plot(jupiter)
colors1 = [orb[2] for orb in op.trajectories]
op.set_frame(*jupiter.pqw())
colors2 = [orb[2] for orb in op.trajectories]
assert colors1 == colors2
def test_savefig_calls_prepare_plot(mock_prepare_plot, mock_export):
m = OrbitPlotter2D()
earth = Orbit.from_body_ephem(Earth)
m.plot(orbit=earth, label="Obj")
with tempfile.NamedTemporaryFile() as fp:
m.savefig(filename=fp.name + ".jpeg")
assert mock_export.call_count == 1
mock_prepare_plot.assert_called_once_with()
def test_plot_trajectory_plots_a_trajectory():
frame = OrbitPlotter2D()
assert len(frame._data) == 0
earth = Orbit.from_body_ephem(Earth)
_, trajectory = earth.sample()
frame.set_attractor(Sun)
frame.plot_trajectory(trajectory)
assert len(frame._data) == 1
assert frame._attractor == Sun
def test_plot_trajectory_plots_a_trajectory():
frame = OrbitPlotter2D()
assert len(frame._data) == 0
earth = Orbit.from_body_ephem(Earth)
trajectory = earth.sample()
frame.set_attractor(Sun)
frame.plot_trajectory(trajectory)
assert len(frame._data) == 1
assert frame._attractor == Sun
def test_show_calls_prepare_plot():
patcher = mock.patch.object(OrbitPlotter3D, '_prepare_plot')
patched = patcher.start()
m = OrbitPlotter3D()
earth = Orbit.from_body_ephem(Earth)
m.plot(orbit=earth, label="Object")
m.show()
assert patched.call_count == 1
patched.assert_called_with()
def test_savefig_calls_prepare_plot():
patcher = mock.patch.object(OrbitPlotter2D, '_prepare_plot')
patched = patcher.start()
m = OrbitPlotter2D()
earth = Orbit.from_body_ephem(Earth)
m.plot(orbit=earth, label="Obj")
m.savefig(filename="a.jpeg")
assert patched.call_count == 1
patched.assert_called_with()
def test_savefig_calls_prepare_plot(mock_export, plotter_class):
with mock.patch.object(plotter_class,
"_prepare_plot") as mock_prepare_plot:
m = plotter_class()
earth = Orbit.from_body_ephem(Earth)
m.plot(orbit=earth, label="Object")
with tempfile.NamedTemporaryFile() as fp:
m.savefig(filename=fp.name + ".jpeg")
assert mock_export.call_count == 1
mock_prepare_plot.assert_called_with()
def test_plot_2d_trajectory_plots_a_trajectory():
frame = OrbitPlotter2D()
assert len(frame.trajectories) == 0
earth = Orbit.from_body_ephem(Earth)
trajectory = earth.sample()
frame.set_attractor(Sun)
frame.set_frame(*earth.pqw())
frame.plot_trajectory(trajectory)
assert len(frame.trajectories) == 1
assert frame._attractor == Sun
def test_savefig_calls_prepare_plot():
patcher = mock.patch.object(OrbitPlotter3D, '_prepare_plot')
patched = patcher.start()
m = OrbitPlotter3D()
earth = Orbit.from_body_ephem(Earth)
m.plot(orbit=earth, label="Object")
with tempfile.NamedTemporaryFile() as fp:
m.savefig(filename=fp.name + ".jpeg")
assert patched.call_count == 1
patched.assert_called_with()
def build_ephem_interpolant(body, period, t_span, rtol=1e-5):
h = period * rtol
t_values = np.linspace(t_span[0], t_span[1] + 0.01, int((t_span[1] - t_span[0]) / h))
r_values = np.zeros((t_values.shape[0], 3))
for i, t in enumerate(t_values):
epoch = Time(t, format='jd', scale='tdb')
body_t = Orbit.from_body_ephem(body, epoch)
body_t = transform(body_t, ICRS, GCRS)
r_values[i] = body_t.r
t_values = ((t_values - t_span[0]) * u.day).to(u.s).value
return interp1d(t_values, r_values, kind='cubic', axis=0, assume_sorted=True)
def test_orbit_from_ephem_is_in_icrs_frame(body):
ss = Orbit.from_body_ephem(body)
assert ss.frame.is_equivalent_frame(ICRS())
def test_from_ephem_raises_error_for_pluto_moon(body):
with pytest.raises(RuntimeError) as excinfo:
Orbit.from_body_ephem(body)
assert "To compute the position and velocity" in excinfo.exconly()
def test_orbit_from_ephem_with_no_epoch_is_today():
# This is not that obvious http://stackoverflow.com/q/6407362/554319
body = Earth
ss = Orbit.from_body_ephem(body)
assert (Time.now() - ss.epoch).sec < 1
def plot_object(objectplo):
obj = Orbit.from_body_ephem(objectplo)
a = OrbitPlotter3D()
a.plot(orbit=obj, label=str(objectplo))
return a.figure
def test_orbit_from_ephem_with_no_epoch_is_today():
# This is not that obvious http://stackoverflow.com/q/6407362/554319
body = Earth
ss = Orbit.from_body_ephem(body)
assert (Time.now() - ss.epoch).sec < 1
def test_orbit_from_ephem_is_in_icrs_frame(body):
ss = Orbit.from_body_ephem(body)
assert ss.frame.is_equivalent_frame(ICRS())
def test_from_ephem_raises_error_for_pluto_moon(body):
with pytest.raises(RuntimeError) as excinfo:
Orbit.from_body_ephem(body)
assert "To compute the position and velocity" in excinfo.exconly()
