Merge pull request #2552 from dhomeier/more-wcs-autolink

Fix incorrect autolinking of axes of unknown physical types in presence of celestial axes

Author: astrofrog

glue/plugins/wcs_autolinking/tests/test_wcs_autolinking.py

@@ -40,6 +40,7 @@ def test_wcs_autolink_emptywcs():
     links = wcs_autolink(dc)
     assert len(links) == 0
 
+
 def test_wcs_autolink_2D_emptywcs():
 
     # No links should be found because the WCS don't actually have well defined
@@ -57,6 +58,7 @@ def test_wcs_autolink_2D_emptywcs():
     links = wcs_autolink(dc)
     assert len(links) == 0
 
+
 def test_wcs_autolink_spectral_cube():
 
     # This should link all coordinates
@@ -196,14 +198,17 @@ def test_link_editor():
     assert link2.data2.label == 'Data 2'
 
 
-def test_celestial_with_unknown_axes():
+@pytest.mark.parametrize('physical_types',
+                         [['SPAM', 'FREQ'], ['SPAM', 'EGGS'], ['WAVE', ''], ['', '']])
+def test_celestial_with_unknown_axes(physical_types):
 
     # Regression test for a bug that caused n-d datasets with celestial axes
     # and axes with unknown physical types to not even be linked by celestial
-    # axes.
+    # axes. Also testing various corner cases with one or both datasets having
+    # unknown or no physical type.
 
     wcs1 = WCS(naxis=3)
-    wcs1.wcs.ctype = 'DEC--TAN', 'RA---TAN', 'SPAM'
+    wcs1.wcs.ctype = 'DEC--TAN', 'RA---TAN', physical_types[0]
     wcs1.wcs.set()
 
     data1 = Data()
@@ -212,7 +217,7 @@ def test_celestial_with_unknown_axes():
     pz1, py1, px1 = data1.pixel_component_ids
 
     wcs2 = WCS(naxis=3)
-    wcs2.wcs.ctype = 'GLON-CAR', 'FREQ', 'GLAT-CAR'
+    wcs2.wcs.ctype = 'GLON-CAR', physical_types[1], 'GLAT-CAR'
     wcs2.wcs.set()
 
     data2 = Data()

glue/plugins/wcs_autolinking/wcs_autolinking.py

@@ -113,8 +113,7 @@ def __init__(self, data1=None, data2=None, cids1=None, cids2=None):
 
         if (wcs1.world_axis_physical_types.count(None) == wcs1.world_n_dim or
             wcs2.world_axis_physical_types.count(None) == wcs2.world_n_dim):
-            raise IncompatibleWCS("Can't create WCS link between {0} and {1}".format(data1.label, data2.label))
-
+            raise IncompatibleWCS(f"Can't create WCS link between {data1.label} and {data2.label}")
 
         forwards = backwards = None
         if wcs1.pixel_n_dim == wcs2.pixel_n_dim and wcs1.world_n_dim == wcs2.world_n_dim:
@@ -133,8 +132,6 @@ def __init__(self, data1=None, data2=None, cids1=None, cids2=None):
                 self._physical_types_1 = wcs1.world_axis_physical_types
                 self._physical_types_2 = wcs2.world_axis_physical_types
 
-
-
         if not forwards or not backwards:
             # A generalized APE 14-compatible way
             # Handle also the extra-spatial axes such as those of the time and wavelength dimensions
@@ -173,14 +170,15 @@ def __init__(self, data1=None, data2=None, cids1=None, cids2=None):
                 wcs2_sliced_physical_types = wcs2_celestial_physical_types
 
             for i, physical_type1 in enumerate(wcs1.world_axis_physical_types):
-                for j, physical_type2 in enumerate(wcs2.world_axis_physical_types):
-                    if physical_type1 == physical_type2:
-                        if physical_type1 not in wcs1_sliced_physical_types:
-                            slicing_axes1.append(wcs1.world_n_dim - i - 1)
-                            wcs1_sliced_physical_types.append(physical_type1)
-                        if physical_type2 not in wcs2_sliced_physical_types:
-                            slicing_axes2.append(wcs2.world_n_dim - j - 1)
-                            wcs2_sliced_physical_types.append(physical_type2)
+                if physical_type1 is not None:
+                    for j, physical_type2 in enumerate(wcs2.world_axis_physical_types):
+                        if physical_type1 == physical_type2:
+                            if physical_type1 not in wcs1_sliced_physical_types:
+                                slicing_axes1.append(wcs1.world_n_dim - i - 1)
+                                wcs1_sliced_physical_types.append(physical_type1)
+                            if physical_type2 not in wcs2_sliced_physical_types:
+                                slicing_axes2.append(wcs2.world_n_dim - j - 1)
+                                wcs2_sliced_physical_types.append(physical_type2)
 
             slicing_axes1 = sorted(slicing_axes1, key=str, reverse=True)
             slicing_axes2 = sorted(slicing_axes2, key=str, reverse=True)
@@ -215,7 +213,7 @@ def __init__(self, data1=None, data2=None, cids1=None, cids2=None):
             self._physical_types_2 = wcs2_sliced_physical_types
 
         if pixel_cids1 is None:
-            raise IncompatibleWCS("Can't create WCS link between {0} and {1}".format(data1.label, data2.label))
+            raise IncompatibleWCS(f"Can't create WCS link between {data1.label} and {data2.label}")
 
         super(WCSLink, self).__init__(pixel_cids1, pixel_cids2,
                                       forwards=forwards, backwards=backwards)
@@ -243,8 +241,7 @@ def description(self):
                 'two datasets using the World Coordinate System (WCS) '
                 'coordinates defined in the files.<br><br>The physical types '
                 'of the coordinates linked in the first dataset are: '
-                '<ul>{0}</ul>and in the second dataset:<ul>{1}</ul>'
-                .format(types1, types2))
+                f'<ul>{types1}</ul>and in the second dataset:<ul>{types2}</ul>')
 
     def as_affine_link(self, n_samples=1000, tolerance=1):
         """