def test_sip_hst():
"""Test SIP against astropy.wcs"""
test_file = get_pkg_data_filename(os.path.join('data', 'hst_sip.hdr'))
hdr = fits.Header.fromtextfile(test_file)
crpix1 = hdr['CRPIX1']
crpix2 = hdr['CRPIX2']
wobj = wcs.WCS(hdr)
a_pars = dict(**hdr['A_*'])
b_pars = dict(**hdr['B_*'])
a_order = a_pars.pop('A_ORDER')
b_order = b_pars.pop('B_ORDER')
sip = SIP([crpix1, crpix2], a_order, b_order, a_pars, b_pars)
coords = [1, 1]
rel_coords = [1 - crpix1, 1 - crpix2]
astwcs_result = wobj.sip_pix2foc([coords], 1)[0] - rel_coords
assert_allclose(sip(1, 1), astwcs_result)
# Test changing of inputs and calling it with keyword argumenrts.
sip.inputs = ("r", "t")
assert_allclose(sip(r=1, t=1), astwcs_result)
assert_allclose(sip(1, t=1), astwcs_result)
def test_sip_hst():
"""Test SIP against astropy.wcs"""
test_file = get_pkg_data_filename(os.path.join('data', 'hst_sip.hdr'))
hdr = fits.Header.fromtextfile(test_file)
crpix1 = hdr['CRPIX1']
crpix2 = hdr['CRPIX2']
wobj = wcs.WCS(hdr)
a_pars = dict(**hdr['A_*'])
b_pars = dict(**hdr['B_*'])
a_order = a_pars.pop('A_ORDER')
b_order = b_pars.pop('B_ORDER')
sip = SIP([crpix1, crpix2], a_order, b_order, a_pars, b_pars)
coords = [1, 1]
rel_coords = [1 - crpix1, 1 - crpix2]
astwcs_result = wobj.sip_pix2foc([coords], 1)[0] - rel_coords
assert_allclose(sip(1, 1), astwcs_result)
# Test changing of inputs and calling it with keyword argumenrts.
sip.inputs = ("r", "t")
assert_allclose(sip(r=1, t=1), astwcs_result)
assert_allclose(sip(1, t=1), astwcs_result)
# Test representations
assert repr(sip) == (
"<SIP([<Shift(offset=-2048.)>, <Shift(offset=-1024.)>, "
"<_SIP1D(4, 'A', A_2_0=0.00000855, A_3_0=-0., A_4_0=0., A_0_2=0.00000217, "
"A_0_3=0., A_0_4=0., A_1_1=-0.0000052, A_1_2=-0., A_1_3=-0., "
"A_2_1=-0., A_2_2=0., A_3_1=0.)>, "
"<_SIP1D(4, 'B', B_2_0=-0.00000175, B_3_0=0., B_4_0=-0., B_0_2=-0.00000722, "
"B_0_3=-0., B_0_4=-0., B_1_1=0.00000618, B_1_2=-0., B_1_3=0., "
"B_2_1=-0., B_2_2=-0., B_3_1=-0.)>])>")
with conf.set_temp('max_width', 80):
assert str(sip) == (
"Model: SIP\n"
" Model: Shift\n"
" Inputs: ('x',)\n"
" Outputs: ('y',)\n"
" Model set size: 1\n"
" Parameters:\n"
" offset\n"
" -------\n"
" -2048.0\n"
"\n"
" Model: Shift\n"
" Inputs: ('x',)\n"
" Outputs: ('y',)\n"
" Model set size: 1\n"
" Parameters:\n"
" offset\n"
" -------\n"
" -1024.0\n"
"\n"
" Model: _SIP1D\n"
" Inputs: ('x', 'y')\n"
" Outputs: ('z',)\n"
" Model set size: 1\n"
" Order: 4\n"
" Coeff. Prefix: A\n"
" Parameters:\n"
" A_2_0 A_3_0 ... A_3_1 \n"
" --------------------- ---------------------- ... ---------------------\n"
" 8.551277582556502e-06 -4.730444829222791e-10 ... 1.971022971660309e-15\n"
"\n"
" Model: _SIP1D\n"
" Inputs: ('x', 'y')\n"
" Outputs: ('z',)\n"
" Model set size: 1\n"
" Order: 4\n"
" Coeff. Prefix: B\n"
" Parameters:\n"
" B_2_0 B_3_0 ... B_3_1 \n"
" ---------------------- --------------------- ... ----------------------\n"
" -1.746491877058669e-06 8.567635427816317e-11 ... -3.779506805487476e-15\n"
)
# Test get num of coeffs
assert sip.sip1d_a.get_num_coeff(1) == 6
# Test error
message = "Degree of polynomial must be 2< deg < 9"
sip.sip1d_a.order = 1
with pytest.raises(ValueError) as err:
sip.sip1d_a.get_num_coeff(1)
assert str(err.value) == message
sip.sip1d_a.order = 10
with pytest.raises(ValueError) as err:
sip.sip1d_a.get_num_coeff(1)
assert str(err.value) == message