def test__flux_at_radius__different_rotate_phi_90_same_result(self):
sersic = light_profile.SersicLightProfile(axis_ratio=0.5,
phi=0.0,
flux=3.0,
effective_radius=2.0,
sersic_index=2.0)
flux_at_radius_1 = sersic.flux_at_coordinates(coordinates=(0, 1))
sersic = light_profile.SersicLightProfile(axis_ratio=0.5,
phi=90.0,
flux=3.0,
effective_radius=2.0,
sersic_index=2.0)
flux_at_radius_2 = sersic.flux_at_coordinates(coordinates=(1, 0))
assert flux_at_radius_1 == flux_at_radius_2
def test_2d_symmetry(self):
sersic1 = light_profile.SersicLightProfile(axis_ratio=1.0,
phi=0.0,
flux=1.0,
effective_radius=0.6,
sersic_index=4.0)
sersic2 = light_profile.SersicLightProfile(axis_ratio=1.0,
phi=0.0,
flux=1.0,
effective_radius=0.6,
sersic_index=4.0,
centre=(100, 0))
sersic3 = light_profile.SersicLightProfile(axis_ratio=1.0,
phi=0.0,
flux=1.0,
effective_radius=0.6,
sersic_index=4.0,
centre=(0, 100))
sersic4 = light_profile.SersicLightProfile(axis_ratio=1.0,
phi=0.0,
flux=1.0,
effective_radius=0.6,
sersic_index=4.0,
centre=(100, 100))
combined = light_profile.CombinedLightProfile(sersic1, sersic2,
sersic3, sersic4)
assert combined.flux_at_coordinates(
(49, 0)) == pytest.approx(combined.flux_at_coordinates((51, 0)),
1e-5)
assert combined.flux_at_coordinates(
(0, 49)) == pytest.approx(combined.flux_at_coordinates((0, 51)),
1e-5)
assert combined.flux_at_coordinates(
(100,
49)) == pytest.approx(combined.flux_at_coordinates((100, 51)),
1e-5)
assert combined.flux_at_coordinates(
(49, 49)) == pytest.approx(combined.flux_at_coordinates((51, 51)),
1e-5)
def test_1d_symmetry(self):
sersic1 = light_profile.SersicLightProfile(axis_ratio=1.0,
phi=0.0,
flux=1.0,
effective_radius=0.6,
sersic_index=4.0)
sersic2 = light_profile.SersicLightProfile(axis_ratio=1.0,
phi=0.0,
flux=1.0,
effective_radius=0.6,
sersic_index=4.0,
centre=(100, 0))
combined = light_profile.CombinedLightProfile(sersic1, sersic2)
assert combined.flux_at_coordinates(
(0, 0)) == combined.flux_at_coordinates((100, 0))
assert combined.flux_at_coordinates(
(49, 0)) == combined.flux_at_coordinates((51, 0))
def test__flux_at_radius__different_axis_ratio(self):
sersic = light_profile.SersicLightProfile(axis_ratio=0.5,
phi=0.0,
flux=3.0,
effective_radius=2.0,
sersic_index=2.0)
flux_at_radius = sersic.flux_at_coordinates(coordinates=(0, 1))
assert flux_at_radius == pytest.approx(5.38066670129, 1e-3)
def test__flux_at_radius_2__correct_value(self):
sersic = light_profile.SersicLightProfile(axis_ratio=1.0,
phi=0.0,
flux=3.0,
effective_radius=2.0,
sersic_index=2.0)
flux_at_radius = sersic.flux_at_radius(
radius=1.5
) # 3.0 * exp(-3.67206544592 * (1,5/2.0) ** (1.0 / 2.0)) - 1) = 0.351797
assert flux_at_radius == pytest.approx(4.90657319276, 1e-3)
def circular_sersic():
return light_profile.SersicLightProfile(axis_ratio=1.0,
phi=0.0,
flux=1.0,
effective_radius=0.6,
sersic_index=4.0)
def vertical_sersic():
return light_profile.SersicLightProfile(axis_ratio=0.5,
phi=90.0,
flux=1.0,
effective_radius=0.6,
sersic_index=4.0)