Check shapes of arrays is consistent

src/py4vasp/_third_party/view/view.py

@@ -147,6 +147,7 @@ def _verify(self):
         self._raise_error_if_present_on_multiple_steps(self.grid_scalars)
         self._raise_error_if_present_on_multiple_steps(self.ion_arrows)
         self._raise_error_if_number_steps_inconsistent()
+        self._raise_error_if_any_shape_is_incorrect()
 
     def _raise_error_if_present_on_multiple_steps(self, attributes):
         if not attributes:
@@ -171,6 +172,17 @@ def _raise_error_if_number_steps_inconsistent(self):
             "steps."
         )
 
+    def _raise_error_if_any_shape_is_incorrect(self):
+        number_elements = len(self.elements[0])
+        _, number_positions, vector_size = np.shape(self.positions)
+        if number_elements != number_positions:
+            raise exception.IncorrectUsage(f"Number of elements ({number_elements}) inconsistent with number of positions ({number_positions}).")
+        if vector_size != 3:
+            raise exception.IncorrectUsage(f"Positions must have three components and not {vector_size}.")
+        cell_shape = np.shape(self.lattice_vectors)[1:]
+        if any(length != 3 for length in cell_shape):
+            raise exception.IncorrectUsage(f"Lattice vectors must be a 3x3 unit cell but have the shape {cell_shape}.")
+
     def _create_atoms(self, step):
         symbols = "".join(self.elements[step])
         atoms = ase.Atoms(symbols)

tests/third_party/view/test_view.py

@@ -320,3 +320,14 @@ def test_different_number_of_steps_raises_error(view):
         broken_view = copy.copy(view)
         broken_view.positions = too_many_positions
         broken_view.to_ngl()
+
+def test_incorrect_shape_raises_error(view):
+    different_number_atoms = np.zeros((len(view.positions), 7, 3))
+    with pytest.raises(exception.IncorrectUsage):
+        View(view.elements, view.lattice_vectors, different_number_atoms)
+    not_a_three_component_vector = np.array(view.positions)[:,:,:2]
+    with pytest.raises(exception.IncorrectUsage):
+        View(view.elements, view.lattice_vectors, not_a_three_component_vector)
+    incorrect_unit_cell = np.zeros((len(view.lattice_vectors), 2, 4))
+    with pytest.raises(exception.IncorrectUsage):
+        View(view.elements, incorrect_unit_cell, view.positions)