Override cfdm.Field.get_domain to store axes cyclicity

Changelog.rst

@@ -44,9 +44,12 @@ version 3.16.2
 * Fix bug whereby `Field.cyclic` is not updated after a
   `Field.del_construct` operation
   (https://github.com/NCAS-CMS/cf-python/issues/758)
+* Fix bug that meant `cyclic()` always returned an empty
+  set for domains produced by `cf.Field.domain`
+  (https://github.com/NCAS-CMS/cf-python/issues/762)
 * Changed dependency: ``cfunits>=3.3.7``
 * Changed dependency: ``netCDF4>=1.6.5``
-  
+
 ----
 
 version 3.16.1

cf/field.py

@@ -2691,6 +2691,30 @@ def cfa_update_file_substitutions(
             for c in self.constructs.filter_by_data(todict=True).values():
                 c.cfa_update_file_substitutions(substitutions)
 
+    def get_domain(self):
+        """Return the domain.
+
+        .. versionadded:: NEXTVERSION
+
+        .. seealso:: `domain`
+
+        :Returns:
+
+            `Domain`
+                 The domain.
+
+        **Examples**
+
+        >>> d = f.get_domain()
+
+        """
+        domain = super().get_domain()
+
+        # Set axis cyclicity for the domain
+        domain._cyclic = self._cyclic
+
+        return domain
+
     def radius(self, default=None):
         """Return the radius of a latitude-longitude plane defined in
         spherical polar coordinates.
@@ -10455,9 +10479,9 @@ def convolution_filter(
                     new_bounds[0 : length - lower_offset, 1:] = old_bounds[
                         lower_offset:length, 1:
                     ]
-                    new_bounds[
-                        length - lower_offset : length, 1:
-                    ] = old_bounds[length - 1, 1:]
+                    new_bounds[length - lower_offset : length, 1:] = (
+                        old_bounds[length - 1, 1:]
+                    )
 
                 coord.set_bounds(self._Bounds(data=new_bounds))
 

cf/mixin/fielddomain.py

@@ -1909,7 +1909,7 @@ def coordinate_reference_domain_axes(self, identity=None):
     def cyclic(
         self, *identity, iscyclic=True, period=None, config={}, **filter_kwargs
     ):
-        """Set the cyclicity of an axis.
+        """Get or set the cyclicity of an axis.
 
         .. versionadded:: 1.0
 

cf/mixin/propertiesdata.py

@@ -2934,7 +2934,7 @@ def count_masked(self):
         return data.count_masked()
 
     def cyclic(self, axes=None, iscyclic=True):
-        """Set the cyclicity of an axis.
+        """Get or set the cyclicity of an axis.
 
         .. seealso:: `iscyclic`
 

cf/mixin/propertiesdatabounds.py

@@ -1607,7 +1607,7 @@ def cos(self, bounds=True, inplace=False, i=False):
         )
 
     def cyclic(self, axes=None, iscyclic=True):
-        """Set the cyclicity of axes of the data array.
+        """Get or set the cyclicity of axes of the data array.
 
         .. seealso:: `iscyclic`
 

cf/test/test_Domain.py

@@ -428,6 +428,35 @@ def test_Domain_del_construct(self):
         self.assertIsInstance(e.del_construct("domainaxis2"), cf.DomainAxis)
         self.assertEqual(e.cyclic(), set())
 
+    def test_Domain_cyclic_iscyclic(self):
+        """Test the `cyclic` and `iscyclic` Domain methods."""
+        # A field and its domain should have the same cyclic() output.
+        f1 = cf.example_field(1)  # no cyclic axes
+        d1 = f1.domain
+        f2 = cf.example_field(2)  # one cyclic axis, 'domainaxis2' ('X')
+        d2 = f2.domain
+
+        # Getting
+        self.assertEqual(d1.cyclic(), f1.cyclic())
+        self.assertEqual(d1.cyclic(), set())
+        self.assertFalse(d1.iscyclic("X"))
+        self.assertFalse(d1.iscyclic("Y"))
+        self.assertFalse(d1.iscyclic("Z"))
+        self.assertFalse(d1.iscyclic("T"))
+        self.assertEqual(d2.cyclic(), f2.cyclic())
+        self.assertEqual(d2.cyclic(), set(("domainaxis2",)))
+        self.assertTrue(d2.iscyclic("X"))
+        self.assertFalse(d2.iscyclic("Y"))
+        self.assertFalse(d2.iscyclic("Z"))
+        self.assertFalse(d2.iscyclic("T"))
+
+        # Setting
+        self.assertEqual(d2.cyclic("X", iscyclic=False), set(("domainaxis2",)))
+        self.assertEqual(d2.cyclic(), set())
+        self.assertEqual(d2.cyclic("X", period=360), set())
+        self.assertEqual(d2.cyclic(), set(("domainaxis2",)))
+        self.assertTrue(d2.iscyclic("X"))
+
 
 if __name__ == "__main__":
     print("Run date:", datetime.datetime.now())

cf/test/test_Field.py

@@ -2859,6 +2859,30 @@ def test_Field_pad_missing(self):
         self.assertEqual(g.shape, (6, 11))
         self.assertTrue(g[5, :].mask.all())
 
+    def test_Field_cyclic_iscyclic(self):
+        """Test the `cyclic` and `iscyclic` Field methods."""
+        f1 = cf.example_field(1)  # no cyclic axes
+        f2 = cf.example_field(2)  # one cyclic axis, 'domainaxis2' ('X')
+
+        # Getting
+        self.assertEqual(f1.cyclic(), set())
+        self.assertFalse(f1.iscyclic("X"))
+        self.assertFalse(f1.iscyclic("Y"))
+        self.assertFalse(f1.iscyclic("Z"))
+        self.assertFalse(f1.iscyclic("T"))
+        self.assertEqual(f2.cyclic(), set(("domainaxis2",)))
+        self.assertTrue(f2.iscyclic("X"))
+        self.assertFalse(f2.iscyclic("Y"))
+        self.assertFalse(f2.iscyclic("Z"))
+        self.assertFalse(f2.iscyclic("T"))
+
+        # Setting
+        self.assertEqual(f2.cyclic("X", iscyclic=False), set(("domainaxis2",)))
+        self.assertEqual(f2.cyclic(), set())
+        self.assertEqual(f2.cyclic("X", period=360), set())
+        self.assertEqual(f2.cyclic(), set(("domainaxis2",)))
+        self.assertTrue(f2.iscyclic("X"))
+
 
 if __name__ == "__main__":
     print("Run date:", datetime.datetime.now())