def test_trim_with_wcs_alters_wcs():
ccd_data = ccd_data_func()
# WCS construction example pulled form astropy.wcs docs
wcs = WCS(naxis=2)
wcs.wcs.crpix = np.array(ccd_data.shape) / 2
wcs.wcs.cdelt = np.array([-0.066667, 0.066667])
wcs.wcs.crval = [0, -90]
wcs.wcs.ctype = ["RA---AIR", "DEC--AIR"]
wcs.wcs.set_pv([(2, 1, 45.0)])
ccd_wcs = CCDData(ccd_data, wcs=wcs)
# The trim below should subtract 10 from the 2nd element of crpix.
# (Second element because the FITS convention for index ordering is
# opposite that of python)
trimmed = trim_image(ccd_wcs[10:, :])
assert trimmed.wcs.wcs.crpix[1] == wcs.wcs.crpix[1] - 10
def test_trim_image_fits_section(mask_data, uncertainty):
ccd_data = ccd_data_func(data_size=50)
if mask_data:
ccd_data.mask = np.zeros_like(ccd_data)
if uncertainty:
err = np.random.normal(size=ccd_data.shape)
ccd_data.uncertainty = StdDevUncertainty(err)
trimmed = trim_image(ccd_data, fits_section='[20:40,:]')
# FITS reverse order, bounds are inclusive and starting index is 1-based
assert trimmed.shape == (50, 21)
np.testing.assert_array_equal(trimmed.data, ccd_data[:, 19:40])
if mask_data:
assert trimmed.shape == trimmed.mask.shape
if uncertainty:
assert trimmed.shape == trimmed.uncertainty.array.shape
def test_trim_image_does_not_change_input():
ccd_data = ccd_data_func()
original = ccd_data.copy()
ccd = trim_image(ccd_data, fits_section=None)
np.testing.assert_array_equal(original.data, ccd_data.data)
assert original.unit == ccd_data.unit
def test_trim_image_no_section():
ccd_data = ccd_data_func(data_size=50)
trimmed = trim_image(ccd_data[:, 19:40])
assert trimmed.shape == (50, 21)
np.testing.assert_array_equal(trimmed.data, ccd_data[:, 19:40])
def test_trim_image_fits_section_requires_string():
ccd_data = ccd_data_func()
with pytest.raises(TypeError):
trim_image(ccd_data, fits_section=5)
def _trimImage(self, image):
ima_trim = trim_image(image, image.header['DATASEC'])
return ima_trim