def test_contour_return():
# Regression test for a bug that caused contour and contourf to return None
# instead of the contour object.
fig = plt.figure()
ax = WCSAxes(fig, [0.1, 0.1, 0.8, 0.8])
fig.add_axes(ax)
cset = ax.contour(np.arange(16).reshape(4, 4), transform=ax.get_transform('world'))
assert isinstance(cset, QuadContourSet)
cset = ax.contourf(np.arange(16).reshape(4, 4), transform=ax.get_transform('world'))
assert isinstance(cset, QuadContourSet)
def test_contour_empty():
# Regression test for a bug that caused contour to crash if no contours
# were present.
fig = plt.figure()
ax = WCSAxes(fig, [0.1, 0.1, 0.8, 0.8])
fig.add_axes(ax)
ax.contour(np.zeros((4, 4)), transform=ax.get_transform('world'))
def test_contour_empty():
# Regression test for a bug that caused contour to crash if no contours
# were present.
fig = plt.figure()
ax = WCSAxes(fig, [0.1, 0.1, 0.8, 0.8])
fig.add_axes(ax)
with pytest.warns(UserWarning, match='No contour levels were found within the data range'):
ax.contour(np.zeros((4, 4)), transform=ax.get_transform('world'))