def fitswcs_transform_from_model(wcsinfo, wavetable=None):
"""
Create a WCS object using from datamodel.meta.wcsinfo.
Transforms assume 0-based coordinates.
Parameters
----------
wcsinfo : dict-like
``~jwst.meta.wcsinfo`` structure.
Return
------
transform : `~astropy.modeling.core.Model`
WCS forward transform - from pixel to world coordinates.
"""
spatial_axes, spectral_axes, unknown = gwutils.get_axes(wcsinfo)
transform = gwutils.make_fitswcs_transform(wcsinfo)
if spectral_axes:
sp_axis = spectral_axes[0]
if wavetable is None:
# Subtract one from CRPIX which is 1-based.
spectral_transform = astmodels.Shift(-(wcsinfo['CRPIX'][sp_axis] - 1)) | \
astmodels.Scale(wcsinfo['CDELT'][sp_axis]) | \
astmodels.Shift(wcsinfo['CRVAL'][sp_axis])
else:
# Wave dimension is an array that needs to be converted to a table
waves = wavetable['wavelength'].flatten()
spectral_transform = astmodels.Tabular1D(lookup_table=waves)
transform = transform & spectral_transform
return transform
def fitswcs_transform_from_model(wcsinfo):
"""
Create a WCS object using from datamodel.meta.wcsinfo.
Transforms assume 0-based coordinates.
Parameters
----------
wcsinfo : dict-like
``~jwst.meta.wcsinfo`` structure.
Return
------
transform : `~astropy.modeling.core.Model`
WCS forward transform - from pixel to world coordinates.
"""
spatial_axes, spectral_axes, unknown = gwutils.get_axes(wcsinfo)
#sp_axis = spectral_axes[0]
transform = gwutils.make_fitswcs_transform(wcsinfo)
#if wcsinfo['WCSAXES'] == 3:
if spectral_axes:
sp_axis = spectral_axes[0]
# Subtract one from CRPIX which is 1-based.
spectral_transform = astmodels.Shift(-(wcsinfo['CRPIX'][sp_axis] - 1)) | \
astmodels.Scale(wcsinfo['CDELT'][sp_axis]) | \
astmodels.Shift(wcsinfo['CRVAL'][sp_axis])
transform = transform & spectral_transform
return transform
def fitswcs_transform_from_model(wcsinfo, wavetable=None):
"""
Create a WCS object using from datamodel.meta.wcsinfo.
Transforms assume 0-based coordinates.
Parameters
----------
wcsinfo : dict-like
``~jwst.meta.wcsinfo`` structure.
Return
------
transform : `~astropy.modeling.core.Model`
WCS forward transform - from pixel to world coordinates.
"""
spatial_axes, spectral_axes, unknown = gwutils.get_axes(wcsinfo)
#sp_axis = spectral_axes[0]
transform = gwutils.make_fitswcs_transform(wcsinfo)
if spectral_axes:
sp_axis = spectral_axes[0]
if wavetable is None :
# Subtract one from CRPIX which is 1-based.
spectral_transform = astmodels.Shift(-(wcsinfo['CRPIX'][sp_axis] - 1)) | \
astmodels.Scale(wcsinfo['CDELT'][sp_axis]) | \
astmodels.Shift(wcsinfo['CRVAL'][sp_axis])
else :
# Wave dimension is an array that needs to be converted to a table
waves = wavetable['wavelength'].flatten()
spectral_transform = astmodels.Tabular1D(lookup_table=waves)
transform = transform & spectral_transform
return transform
def fitswcs_transform_from_model(input_model):
"""
Create a fits wcs from a datamodel.meta.wcsinfo.
"""
wcsinfo = {}
wcsaxes = input_model._instance['meta']['wcsinfo']['wcsaxes']
wcsinfo['WCSAXES'] = wcsaxes
for key in ['CTYPE', 'CRPIX', 'CRVAL', 'CDELT', 'CUNIT']:
val = []
for ax in range(1, wcsaxes + 1):
try:
val.append(input_model._instance['meta']['wcsinfo'][(
key + "{0}".format(ax)).lower()])
except KeyError:
pass
wcsinfo[key.upper()] = val
pc = np.zeros((wcsaxes, 2))
for i in range(1, wcsaxes + 1):
for j in range(1, 3):
pc[i - 1, j - 1] = input_model._instance['meta']['wcsinfo'][
'pc{0}_{1}'.format(i, j)]
wcsinfo['PC'] = pc
# getting "coordinates" from the schema is currently broken.
wcsinfo[
'RADESYS'] = 'ICRS' #input_model._instance['meta']['coordinates']['reference_frame']
wcsinfo['has_cd'] = False
transform = gwutils.make_fitswcs_transform(wcsinfo)
return transform
def test_reproject():
hdr1 = fits.Header.fromfile(get_pkg_data_filename('data/simple_wcs.hdr'))
hdr2 = fits.Header.fromfile(get_pkg_data_filename('data/simple_wcs2.hdr'))
w1 = fitswcs.WCS(hdr1)
w2 = fitswcs.WCS(hdr2)
gw2 = wcs.WCS(output_frame='icrs',
forward_transform=gwutil.make_fitswcs_transform(hdr2))
func1 = reproject(w1, w2)
func2 = reproject(w1, gw2)
x1, y1 = func1(1, 2)
x2, y2 = func2(1, 2)
utils.assert_allclose(x1, x2, atol=10**-7)
utils.assert_allclose(y1, y2, atol=10**-7)
def test_reproject():
hdr1 = fits.Header.fromfile(get_pkg_data_filename('data/simple_wcs.hdr'))
hdr2 = fits.Header.fromfile(get_pkg_data_filename('data/simple_wcs2.hdr'))
w1 = fitswcs.WCS(hdr1)
w2 = fitswcs.WCS(hdr2)
gw2 = wcs.WCS(output_frame='icrs',
forward_transform=gwutil.make_fitswcs_transform(hdr2))
func1 = reproject(w1, w2)
func2 = reproject(w1, gw2)
x1, y1 = func1(1, 2)
x2, y2 = func2(1, 2)
utils.assert_allclose(x1, x2, atol=10**-7)
utils.assert_allclose(y1, y2, atol=10**-7)
def fitswcs_transform_from_model(wcsinfo):
"""
Create a fits wcs from a datamodel.meta.wcsinfo.
"""
spatial_axes, spectral_axes = gwutils.get_axes(wcsinfo)
transform = gwutils.make_fitswcs_transform(wcsinfo)
if wcsinfo['WCSAXES'] == 3:
spectral_transform = astmodels.Shift(-wcsinfo['CRPIX'][spectral_axes]) | \
astmodels.Scale(wcsinfo['CDELT'][spectral_axes]) | \
astmodels.Shift(wcsinfo['CRVAL'][spectral_axes])
transform = transform & spectral_transform
return transform
def create_fitswcs_transform(input_model):
ff = fits_support.to_fits(input_model._instance, input_model._schema)
hdu = fits_support.get_hdu(ff._hdulist, "PRIMARY")
header = hdu.header
transform = gwutils.make_fitswcs_transform(header)
return transform
def create_fitswcs_transform(input_model):
ff = fits_support.to_fits(input_model._instance, input_model._schema)
hdu = fits_support.get_hdu(ff._hdulist, "PRIMARY")
header = hdu.header
transform = gwutils.make_fitswcs_transform(header)
return transform
