Fix GWCS failures due to the API spring cleaning PR (#8965)

Co-authored-by: Nadia Dencheva <nadia.dencheva@gmail.com>

changes/8965.assign_wcs.rst

@@ -0,0 +1 @@
+Fix use of a string name for the WCS coordinate frame for nirspec ifu.

jwst/assign_wcs/nirspec.py

@@ -229,7 +229,7 @@ def ifu(input_model, reference_files, slit_y_range=[-.55, .55]):
     # SLICER to MSA Entrance
     slicer2msa = slicer_to_msa(reference_files)
 
-    det, sca, gwa, slit_frame, msa_frame, oteip, v2v3, v2v3vacorr, world = create_frames()
+    det, sca, gwa, slit_frame, slicer_frame, msa_frame, oteip, v2v3, v2v3vacorr, world = create_frames()
 
     exp_type = input_model.meta.exposure.type.upper()
 
@@ -241,7 +241,7 @@ def ifu(input_model, reference_files, slit_y_range=[-.55, .55]):
                     (sca, det2gwa.rename('detector2gwa')),
                     (gwa, gwa2slit.rename('gwa2slit')),
                     (slit_frame, slit2slicer),
-                    ('slicer', slicer2msa),
+                    (slicer_frame, slicer2msa),
                     (msa_frame, None)]
     else:
         # MSA to OTEIP transform
@@ -271,7 +271,7 @@ def ifu(input_model, reference_files, slit_y_range=[-.55, .55]):
                     (sca, det2gwa.rename('detector2gwa')),
                     (gwa, gwa2slit.rename('gwa2slit')),
                     (slit_frame, slit2slicer),
-                    ('slicer', slicer2msa),
+                    (slicer_frame, slicer2msa),
                     (msa_frame, msa2oteip.rename('msa2oteip')),
                     (oteip, oteip2v23.rename('oteip2v23')),
                     (v2v3, va_corr),
@@ -352,7 +352,8 @@ def slitlets_wcs(input_model, reference_files, open_slits_id):
 
     # Create coordinate frames in the NIRSPEC WCS pipeline"
     # "detector", "gwa", "slit_frame", "msa_frame", "oteip", "v2v3", "v2v3vacorr", "world"
-    det, sca, gwa, slit_frame, msa_frame, oteip, v2v3, v2v3vacorr, world = create_frames()
+    # _ would be the slicer_frame that is not used
+    det, sca, gwa, slit_frame, _, msa_frame, oteip, v2v3, v2v3vacorr, world = create_frames()
 
     exp_type = input_model.meta.exposure.type.upper()
 
@@ -1593,6 +1594,8 @@ def create_frames():
                              axes_names=('x_msa', 'y_msa'))
     slit_spatial = cf.Frame2D(name='slit_spatial', axes_order=(0, 1), unit=("", ""),
                               axes_names=('x_slit', 'y_slit'))
+    slicer_spatial = cf.Frame2D(name='slicer_spatial', axes_order=(0, 1), unit=("", ""),
+                                axes_names=('x_slicer', 'y_slicer'))
     sky = cf.CelestialFrame(name='sky', axes_order=(0, 1), reference_frame=coord.ICRS())
     v2v3_spatial = cf.Frame2D(name='v2v3_spatial', axes_order=(0, 1),
                               unit=(u.arcsec, u.arcsec), axes_names=('v2', 'v3'))
@@ -1606,12 +1609,13 @@ def create_frames():
     v2v3 = cf.CompositeFrame([v2v3_spatial, spec], name='v2v3')
     v2v3vacorr = cf.CompositeFrame([v2v3vacorr_spatial, spec], name='v2v3vacorr')
     slit_frame = cf.CompositeFrame([slit_spatial, spec], name='slit_frame')
+    slicer_frame = cf.CompositeFrame([slicer_spatial, spec], name='slicer')
     msa_frame = cf.CompositeFrame([msa_spatial, spec], name='msa_frame')
     oteip_spatial = cf.Frame2D(name='oteip', axes_order=(0, 1), unit=(u.deg, u.deg),
                                axes_names=('X_OTEIP', 'Y_OTEIP'))
     oteip = cf.CompositeFrame([oteip_spatial, spec], name='oteip')
     world = cf.CompositeFrame([sky, spec], name='world')
-    return det, sca, gwa, slit_frame, msa_frame, oteip, v2v3, v2v3vacorr, world
+    return det, sca, gwa, slit_frame, slicer_frame, msa_frame, oteip, v2v3, v2v3vacorr, world
 
 
 def create_imaging_frames():

jwst/assign_wcs/tests/test_wcs.py

@@ -148,7 +148,8 @@ def test_frame_from_model_3d(tmp_path, create_model_3d):
     # Test CompositeFrame initialization (celestial and spectral)
     im = create_model_3d
     frame = pointing.frame_from_model(im)
-    radec, lam = frame.coordinates(1, 2, 3)
+
+    radec, lam = frame.to_high_level_coordinates(1, 2, 3)
 
     assert_allclose(radec.spherical.lon.value, 1)
     assert_allclose(radec.spherical.lat.value, 2)

pyproject.toml

@@ -23,7 +23,8 @@ dependencies = [
     "BayesicFitting>=3.0.1",
     "crds>=12.0.3",
     "drizzle>=2.0.0",
-    "gwcs>=0.22.0,<0.23.0",
+    # "gwcs>=0.22.0,<0.23.0",
+    "gwcs @ git+https://github.com/spacetelescope/gwcs.git@master",
     "numpy>=1.25,<2.0",
     "opencv-python-headless>=4.6.0.66",
     "photutils>=1.5.0",