def test_sky_disk():
# Test the disk case (e=0)
r_0 = 2 * u.deg
model = DiskSpatialModel(lon_0="1 deg", lat_0="45 deg", r_0=r_0)
lon = [1, 5, 359] * u.deg
lat = 46 * u.deg
val = model(lon, lat)
assert val.unit == "sr-1"
desired = [261.263956, 0, 261.263956]
assert_allclose(val.value, desired)
radius = model.evaluation_radius
assert radius.unit == "deg"
assert_allclose(radius.value, r_0.value)
# test the normalization for an elongated ellipse near the Galactic Plane
m_geom_1 = WcsGeom.create(
binsz=0.015, width=(20, 20), skydir=(2, 2), frame="galactic", proj="AIT"
)
coords = m_geom_1.get_coord()
solid_angle = m_geom_1.solid_angle()
lon = coords.lon
lat = coords.lat
r_0 = 10 * u.deg
model_1 = DiskSpatialModel(
lon_0=2 * u.deg, lat_0=2 * u.deg, r_0=r_0, e=0.4, phi=30 * u.deg
)
vals_1 = model_1(lon, lat)
assert vals_1.unit == "sr-1"
assert_allclose(np.sum(vals_1 * solid_angle), 1, rtol=1.0e-3)
radius = model_1.evaluation_radius
assert radius.unit == "deg"
assert_allclose(radius.value, r_0.value)
# test rotation
r_0 = 2 * u.deg
semi_minor = 1 * u.deg
eccentricity = np.sqrt(1 - (semi_minor / r_0) ** 2)
model_rot_test = DiskSpatialModel(
lon_0=0 * u.deg, lat_0=0 * u.deg, r_0=r_0, e=eccentricity, phi=90 * u.deg
)
assert_allclose(model_rot_test(0 * u.deg, 1.5 * u.deg).value, 0)
# test the normalization for a disk (ellipse with e=0) at the Galactic Pole
m_geom_2 = WcsGeom.create(
binsz=0.1, width=(6, 6), skydir=(0, 90), frame="galactic", proj="AIT"
)
coords = m_geom_2.get_coord()
lon = coords.lon
lat = coords.lat
r_0 = 5 * u.deg
disk = DiskSpatialModel(lon_0=0 * u.deg, lat_0=90 * u.deg, r_0=r_0)
vals_disk = disk(lon, lat)
solid_angle = 2 * np.pi * (1 - np.cos(5 * u.deg))
assert_allclose(np.max(vals_disk).value * solid_angle, 1)
assert isinstance(model.to_region(), EllipseSkyRegion)
)
phi = Angle("30 deg")
model = DiskSpatialModel(
lon_0="2 deg",
lat_0="2 deg",
r_0="1 deg",
e=0.8,
phi="30 deg",
frame="galactic",
)
ax = model.plot(add_cbar=True)
# illustrate size parameter
region = model.to_region().to_pixel(ax.wcs)
artist = region.as_artist(facecolor="none", edgecolor="red")
ax.add_artist(artist)
transform = ax.get_transform("galactic")
ax.scatter(2, 2, transform=transform, s=20, edgecolor="red", facecolor="red")
ax.text(1.7, 1.85, r"$(l_0, b_0)$", transform=transform, ha="center")
ax.plot([2, 2 + np.sin(phi)], [2, 2 + np.cos(phi)],
color="r",
transform=transform)
ax.vlines(x=2, color="r", linestyle="--", transform=transform, ymin=0, ymax=5)
ax.text(2.15, 2.3, r"$\phi$", transform=transform)
# %%
# This plot illustrates the definition of the edge parameter: