Added a set/get_translation attribute to the Cell C-API interface. This is also tested.

include/openmc/capi.h

@@ -14,12 +14,14 @@ extern "C" {
   int openmc_cell_get_fill(int32_t index, int* type, int32_t** indices, int32_t* n);
   int openmc_cell_get_id(int32_t index, int32_t* id);
   int openmc_cell_get_temperature(int32_t index, const int32_t* instance, double* T);
+  int openmc_cell_get_translation(int32_t index, double xyz[]);
   int openmc_cell_get_name(int32_t index, const char** name);
   int openmc_cell_get_num_instances(int32_t index, int32_t* num_instances);
   int openmc_cell_set_name(int32_t index, const char* name);
   int openmc_cell_set_fill(int32_t index, int type, int32_t n, const int32_t* indices);
   int openmc_cell_set_id(int32_t index, int32_t id);
   int openmc_cell_set_temperature(int32_t index, double T, const int32_t* instance, bool set_contained = false);
+  int openmc_cell_set_translation(int32_t index, const double xyz[]);
   int openmc_energy_filter_get_bins(int32_t index, const double** energies, size_t* n);
   int openmc_energy_filter_set_bins(int32_t index, size_t n, const double* energies);
   int openmc_energyfunc_filter_get_energy(int32_t index, size_t* n, const double** energy);

openmc/lib/cell.py

@@ -35,6 +35,9 @@ _dll.openmc_cell_get_temperature.errcheck = _error_handler
 _dll.openmc_cell_get_name.argtypes = [c_int32, POINTER(c_char_p)]
 _dll.openmc_cell_get_name.restype = c_int
 _dll.openmc_cell_get_name.errcheck = _error_handler
+_dll.openmc_cell_get_translation.argtypes = [c_int32, POINTER(c_double)]
+_dll.openmc_cell_get_translation.restype = c_int
+_dll.openmc_cell_get_translation.errcheck = _error_handler
 _dll.openmc_cell_set_name.argtypes = [c_int32, c_char_p]
 _dll.openmc_cell_set_name.restype = c_int
 _dll.openmc_cell_set_name.errcheck = _error_handler
@@ -49,6 +52,9 @@ _dll.openmc_cell_set_temperature.argtypes = [
     c_int32, c_double, POINTER(c_int32), c_bool]
 _dll.openmc_cell_set_temperature.restype = c_int
 _dll.openmc_cell_set_temperature.errcheck = _error_handler
+_dll.openmc_cell_set_translation.argtypes = [c_int32, POINTER(c_double)]
+_dll.openmc_cell_set_translation.restype = c_int
+_dll.openmc_cell_set_translation.errcheck = _error_handler
 _dll.openmc_get_cell_index.argtypes = [c_int32, POINTER(c_int32)]
 _dll.openmc_get_cell_index.restype = c_int
 _dll.openmc_get_cell_index.errcheck = _error_handler
@@ -213,6 +219,29 @@ class Cell(_FortranObjectWithID):
 
         _dll.openmc_cell_set_temperature(self._index, T, instance, set_contained)
 
+    def get_translation(self):
+        """Get the translation vector of a cell
+
+        """
+
+        translation = np.zeros(3)
+        _dll.openmc_cell_get_translation(
+            self._index, translation.ctypes.data_as(POINTER(c_double)))
+        return translation
+
+    def set_translation(self, translation):
+        """Set the translation vector of a cell
+
+        Parameters
+        ----------
+        translation : numpy.ndarray
+            3-D translation vector
+
+        """
+
+        _dll.openmc_cell_set_translation(
+            self._index, translation.ctypes.data_as(POINTER(c_double)))
+
     @property
     def bounding_box(self):
         inf = sys.float_info.max

src/cell.cpp

@@ -1299,6 +1299,34 @@ openmc_cell_set_id(int32_t index, int32_t id)
   }
 }
 
+//! Return the translation vector of a cell
+extern "C" int openmc_cell_get_translation(int32_t index, double xyz[])
+{
+  if (index >= 0 && index < model::cells.size()) {
+    auto& cell = openmc::model::cells[index];
+    xyz[0] = cell->translation_.x;
+    xyz[1] = cell->translation_.y;
+    xyz[2] = cell->translation_.z;
+    return 0;
+  } else {
+    set_errmsg("Index in cells array is out of bounds.");
+    return OPENMC_E_OUT_OF_BOUNDS;
+  }
+}
+
+//! Set the translation vector of a cell
+extern "C" int openmc_cell_set_translation(int32_t index, const double xyz[])
+{
+  if (index >= 0 && index < model::cells.size()) {
+    model::cells[index]->translation_ = Position(xyz);
+    return 0;
+  } else {
+    set_errmsg("Index in cells array is out of bounds.");
+    return OPENMC_E_OUT_OF_BOUNDS;
+  }
+}
+
+//! Get the number of instances of the requested cell
 extern "C" int
 openmc_cell_get_num_instances(int32_t index, int32_t* num_instances)
 {

tests/unit_tests/test_lib.py

@@ -141,6 +141,12 @@ def test_properties_temperature(lib_init):
     openmc.lib.import_properties('properties.h5')
     assert cell.get_temperature() == pytest.approx(200.0)
 
+def test_cell_translation(lib_init):
+    cell = openmc.lib.cells[1]
+    assert cell.get_translation() == pytest.approx([0., 0., 0.])
+    cell.set_translation(np.array([1., 0., -1.]))
+    assert cell.get_translation() == pytest.approx([1., 0., -1.])
+
 
 def test_new_cell(lib_init):
     with pytest.raises(exc.AllocationError):