def test_slice_with_sip():
mywcs = WCS(naxis=2)
mywcs.wcs.crval = [1, 1]
mywcs.wcs.cdelt = [0.1, 0.1]
mywcs.wcs.crpix = [1, 1]
mywcs._naxis = [1000, 500]
mywcs.wcs.ctype = ['RA---TAN-SIP', 'DEC--TAN-SIP']
a = np.array([[0, 0, 5.33092692e-08, 3.73753773e-11, -2.02111473e-13],
[0, 2.44084308e-05, 2.81394789e-11, 5.17856895e-13, 0.0],
[-2.41334657e-07, 1.29289255e-10, 2.35753629e-14, 0.0, 0.0],
[-2.37162007e-10, 5.43714947e-13, 0.0, 0.0, 0.0],
[-2.81029767e-13, 0.0, 0.0, 0.0, 0.0]])
b = np.array([[0, 0, 2.99270374e-05, -2.38136074e-10, 7.23205168e-13],
[0, -1.71073858e-07, 6.31243431e-11, -5.16744347e-14, 0.0],
[6.95458963e-06, -3.08278961e-10, -1.75800917e-13, 0.0, 0.0],
[3.51974159e-11, 5.60993016e-14, 0.0, 0.0, 0.0],
[-5.92438525e-13, 0.0, 0.0, 0.0, 0.0]])
mywcs.sip = Sip(a, b, None, None, mywcs.wcs.crpix)
mywcs.wcs.set()
pscale = 0.1 # from cdelt
slice_wcs = mywcs.slice([slice(1, None), slice(0, None)])
# test that CRPIX maps to CRVAL:
assert_allclose(slice_wcs.all_pix2world(*slice_wcs.wcs.crpix, 1),
slice_wcs.wcs.crval,
rtol=0.0,
atol=1e-6 * pscale)
slice_wcs = mywcs.slice([slice(1, None, 2), slice(0, None, 4)])
# test that CRPIX maps to CRVAL:
assert_allclose(slice_wcs.all_pix2world(*slice_wcs.wcs.crpix, 1),
slice_wcs.wcs.crval,
rtol=0.0,
atol=1e-6 * pscale)
def test_slice():
mywcs = WCS(naxis=2)
mywcs.wcs.crval = [1, 1]
mywcs.wcs.cdelt = [0.1, 0.1]
mywcs.wcs.crpix = [1, 1]
mywcs._naxis = [1000, 500]
pscale = 0.1 # from cdelt
slice_wcs = mywcs.slice([slice(1, None), slice(0, None)])
assert np.all(slice_wcs.wcs.crpix == np.array([1, 0]))
assert slice_wcs._naxis == [1000, 499]
# test that CRPIX maps to CRVAL:
assert_allclose(
slice_wcs.wcs_pix2world(*slice_wcs.wcs.crpix, 1),
slice_wcs.wcs.crval, rtol=0.0, atol=1e-6 * pscale
)
slice_wcs = mywcs.slice([slice(1, None, 2), slice(0, None, 4)])
assert np.all(slice_wcs.wcs.crpix == np.array([0.625, 0.25]))
assert np.all(slice_wcs.wcs.cdelt == np.array([0.4, 0.2]))
assert slice_wcs._naxis == [250, 250]
slice_wcs = mywcs.slice([slice(None, None, 2), slice(0, None, 2)])
assert np.all(slice_wcs.wcs.cdelt == np.array([0.2, 0.2]))
assert slice_wcs._naxis == [500, 250]
# Non-integral values do not alter the naxis attribute
slice_wcs = mywcs.slice([slice(50.), slice(20.)])
assert slice_wcs._naxis == [1000, 500]
slice_wcs = mywcs.slice([slice(50.), slice(20)])
assert slice_wcs._naxis == [20, 500]
slice_wcs = mywcs.slice([slice(50), slice(20.5)])
assert slice_wcs._naxis == [1000, 50]
def test_slice():
mywcs = WCS(naxis=2)
mywcs.wcs.crval = [1, 1]
mywcs.wcs.cdelt = [0.1, 0.1]
mywcs.wcs.crpix = [1, 1]
mywcs._naxis = [1000, 500]
pscale = 0.1 # from cdelt
slice_wcs = mywcs.slice([slice(1, None), slice(0, None)])
assert np.all(slice_wcs.wcs.crpix == np.array([1, 0]))
assert slice_wcs._naxis == [1000, 499]
# test that CRPIX maps to CRVAL:
assert_allclose(slice_wcs.wcs_pix2world(*slice_wcs.wcs.crpix, 1),
slice_wcs.wcs.crval,
rtol=0.0,
atol=1e-6 * pscale)
slice_wcs = mywcs.slice([slice(1, None, 2), slice(0, None, 4)])
assert np.all(slice_wcs.wcs.crpix == np.array([0.625, 0.25]))
assert np.all(slice_wcs.wcs.cdelt == np.array([0.4, 0.2]))
assert slice_wcs._naxis == [250, 250]
slice_wcs = mywcs.slice([slice(None, None, 2), slice(0, None, 2)])
assert np.all(slice_wcs.wcs.cdelt == np.array([0.2, 0.2]))
assert slice_wcs._naxis == [500, 250]
# Non-integral values do not alter the naxis attribute
slice_wcs = mywcs.slice([slice(50.), slice(20.)])
assert slice_wcs._naxis == [1000, 500]
slice_wcs = mywcs.slice([slice(50.), slice(20)])
assert slice_wcs._naxis == [20, 500]
slice_wcs = mywcs.slice([slice(50), slice(20.5)])
assert slice_wcs._naxis == [1000, 50]
def test_slice_with_sip():
mywcs = WCS(naxis=2)
mywcs.wcs.crval = [1, 1]
mywcs.wcs.cdelt = [0.1, 0.1]
mywcs.wcs.crpix = [1, 1]
mywcs._naxis = [1000, 500]
mywcs.wcs.ctype = ['RA---TAN-SIP', 'DEC--TAN-SIP']
a = np.array(
[[0, 0, 5.33092692e-08, 3.73753773e-11, -2.02111473e-13],
[0, 2.44084308e-05, 2.81394789e-11, 5.17856895e-13, 0.0],
[-2.41334657e-07, 1.29289255e-10, 2.35753629e-14, 0.0, 0.0],
[-2.37162007e-10, 5.43714947e-13, 0.0, 0.0, 0.0],
[ -2.81029767e-13, 0.0, 0.0, 0.0, 0.0]]
)
b = np.array(
[[0, 0, 2.99270374e-05, -2.38136074e-10, 7.23205168e-13],
[0, -1.71073858e-07, 6.31243431e-11, -5.16744347e-14, 0.0],
[6.95458963e-06, -3.08278961e-10, -1.75800917e-13, 0.0, 0.0],
[3.51974159e-11, 5.60993016e-14, 0.0, 0.0, 0.0],
[-5.92438525e-13, 0.0, 0.0, 0.0, 0.0]]
)
mywcs.sip = Sip(a, b, None, None, mywcs.wcs.crpix)
mywcs.wcs.set()
pscale = 0.1 # from cdelt
slice_wcs = mywcs.slice([slice(1, None), slice(0, None)])
# test that CRPIX maps to CRVAL:
assert_allclose(
slice_wcs.all_pix2world(*slice_wcs.wcs.crpix, 1),
slice_wcs.wcs.crval, rtol=0.0, atol=1e-6 * pscale
)
slice_wcs = mywcs.slice([slice(1, None, 2), slice(0, None, 4)])
# test that CRPIX maps to CRVAL:
assert_allclose(
slice_wcs.all_pix2world(*slice_wcs.wcs.crpix, 1),
slice_wcs.wcs.crval, rtol=0.0, atol=1e-6 * pscale
)
