Ensure compatible ordering of unique vectors

Author: viljarjf

diffsims/crystallography/reciprocal_lattice_vector.py

@@ -1529,15 +1529,19 @@ def unique(self, use_symmetry=False, return_index=False, return_inverse=False):
         # TODO: Reduce floating point precision in orix!
         def miller_unique(miller, use_symmetry=False):
             v, idx, inv = Vector3d(miller).unique(return_index=True, return_inverse=True)
-            idx = idx[::-1]
-            inv = inv[::-1]
 
             if use_symmetry:
                 operations = miller.phase.point_group
                 n_v = v.size
-                v2 = operations.outer(v[::-1]).flatten().reshape(*(n_v, operations.size))
-                data = v2.data.round(6)  # Reduced precision
-                _, idx, inv = np.unique(data, return_index=True, return_inverse=True, axis=0)
+                v2 = operations.outer(v).flatten().reshape(*(n_v, operations.size))
+                data = v2.data.round(8)  # Reduced precision
+                # To check for uniqueness, sort the equivalent vectors from each operation
+                data_sorted = np.zeros_like(data)
+                for i in range(n_v):
+                    a = data[i]
+                    order = np.lexsort(a.T)  # Sort by column 1, 2, then 3
+                    data_sorted[i] = a[order[::-1]] # Reverse to preserve order
+                _, idx, inv = np.unique(data_sorted, return_index=True, return_inverse=True, axis=0)
                 v = v[idx]
 
             m = miller.__class__(xyz=v.data, phase=miller.phase)

diffsims/tests/crystallography/test_diffracting_vector.py

@@ -41,8 +41,8 @@ def test_slicing(self, ferrite_phase):
 
     def test_structure_factor(self, ferrite_phase):
         rlv = DiffractingVector.from_min_dspacing(ferrite_phase, 1.5)
-        with pytest.raises(NotImplementedError):
-            rlv.calculate_structure_factor()
+        rlv.calculate_structure_factor()
+        assert np.all(~np.isnan(rlv.structure_factor))
 
     def test_hkl(self, ferrite_phase):
         rlv = ReciprocalLatticeVector(ferrite_phase, hkl=[[1, 1, 1], [2, 0, 0]])