Remove default dimension on from_domain. Add a test

Author: paulromano

openmc/mesh.py

@@ -937,15 +937,29 @@ def _check_vtk_dataset(self, label: str, dataset: np.ndarray):
             )
 
     @classmethod
-    def from_domain(cls, domain, dimension=1000, mesh_id=None, name='', **kwargs):
+    def from_domain(
+        cls,
+        domain: HasBoundingBox | BoundingBox,
+        dimension: Sequence[int] | int | None = None,
+        mesh_id: int | None = None,
+        name: str = '',
+        **kwargs
+    ):
+        """Create a structured mesh from a domain using its bounding box."""
         if isinstance(domain, BoundingBox):
             bbox = domain
         elif hasattr(domain, 'bounding_box'):
             bbox = domain.bounding_box
         else:
             raise TypeError("Domain must be a BoundingBox or have a "
                             "bounding_box property")
-        return cls.from_bounding_box(bbox, dimension=dimension, mesh_id=mesh_id, name=name, **kwargs)
+
+        if dimension is None:
+            return cls.from_bounding_box(
+                bbox, mesh_id=mesh_id, name=name, **kwargs)
+
+        return cls.from_bounding_box(
+            bbox, dimension=dimension, mesh_id=mesh_id, name=name, **kwargs)
 
     @classmethod
     @abstractmethod

tests/unit_tests/test_mesh_from_domain.py

@@ -27,6 +27,20 @@ def test_reg_mesh_from_bounding_box():
     assert np.array_equal(mesh.upper_right, bb[1])
 
 
+def test_rectilinear_mesh_from_bounding_box():
+    """Tests a RectilinearMesh can be made from a BoundingBox directly."""
+    bb = openmc.BoundingBox([-8, -7, -5], [12, 13, 15])
+
+    mesh = openmc.RectilinearMesh.from_bounding_box(bb, dimension=[2, 4, 5])
+    assert isinstance(mesh, openmc.RectilinearMesh)
+    assert np.array_equal(mesh.dimension, (2, 4, 5))
+    assert np.array_equal(mesh.lower_left, bb[0])
+    assert np.array_equal(mesh.upper_right, bb[1])
+    assert np.array_equal(mesh.x_grid, [-8., 2., 12.])
+    assert np.array_equal(mesh.y_grid, [-7., -2., 3., 8., 13.])
+    assert np.array_equal(mesh.z_grid, [-5., -1., 3., 7., 11., 15.])
+
+
 def test_cylindrical_mesh_from_cell():
     """Tests a CylindricalMesh can be made from a Cell and the specified
     dimensions are propagated through."""