def make_output_wcs(input_models, pscale_ratio=1.0):
""" Generate output WCS here based on footprints of all input WCS objects
Parameters
----------
input_models : list of `~jwst.datamodel.DataModel`
Each datamodel must have a ~gwcs.WCS object.
pscale_ratio : float, optional
Ratio of input to output pixel scale.
Returns
-------
output_wcs : object
WCS object, with defined domain, covering entire set of input frames
"""
wcslist = [i.meta.wcs for i in input_models]
for w, i in zip(wcslist, input_models):
if w.bounding_box is None:
w.bounding_box = wcs_bbox_from_shape(i.data.shape)
naxes = wcslist[0].output_frame.naxes
if naxes == 2:
output_wcs = wcs_from_footprints(input_models,
pscale_ratio=pscale_ratio)
output_wcs.data_size = shape_from_bounding_box(output_wcs.bounding_box)
else:
raise RuntimeError("Output WCS needs 2 spatial axes. "
f"{wcslist[0]} has {naxes}.")
# Check that the output data shape has no zero length dimensions
if not np.product(output_wcs.data_size):
raise ValueError("Invalid output frame shape: "
"{}".format(output_wcs.data_size))
return output_wcs
def make_output_wcs(input_models,
ref_wcs=None,
pscale_ratio=None,
pscale=None,
rotation=None,
shape=None,
crpix=None,
crval=None):
""" Generate output WCS here based on footprints of all input WCS objects
Parameters
----------
input_models : list of `~jwst.datamodel.DataModel`
Each datamodel must have a ~gwcs.WCS object.
pscale_ratio : float, optional
Ratio of input to output pixel scale. Ignored when ``pscale`` is provided.
pscale : float, None, optional
Absolute pixel scale in degrees. When provided, overrides
``pscale_ratio``.
rotation : float, None, optional
Position angle of output image’s Y-axis relative to North.
A value of 0.0 would orient the final output image to be North up.
The default of `None` specifies that the images will not be rotated,
but will instead be resampled in the default orientation for the camera
with the x and y axes of the resampled image corresponding
approximately to the detector axes.
shape : tuple of int, None, optional
Shape of the image (data array) using ``numpy.ndarray`` convention
(``ny`` first and ``nx`` second). This value will be assigned to
``pixel_shape`` and ``array_shape`` properties of the returned
WCS object.
crpix : tuple of float, None, optional
Position of the reference pixel in the image array. If ``crpix`` is not
specified, it will be set to the center of the bounding box of the
returned WCS object.
crval : tuple of float, None, optional
Right ascension and declination of the reference pixel. Automatically
computed if not provided.
Returns
-------
output_wcs : object
WCS object, with defined domain, covering entire set of input frames
"""
wcslist = [i.meta.wcs for i in input_models]
for w, i in zip(wcslist, input_models):
if w.bounding_box is None:
w.bounding_box = wcs_bbox_from_shape(i.data.shape)
naxes = wcslist[0].output_frame.naxes
if naxes != 2:
raise RuntimeError("Output WCS needs 2 spatial axes. "
f"{wcslist[0]} has {naxes}.")
output_wcs = wcs_from_footprints(input_models,
pscale_ratio=pscale_ratio,
pscale=pscale,
rotation=rotation,
shape=shape,
crpix=crpix,
crval=crval)
# Check that the output data shape has no zero length dimensions
if not np.product(output_wcs.array_shape):
raise ValueError(
f"Invalid output frame shape: {tuple(output_wcs.array_shape)}")
return output_wcs