Address @wbinventor comments on #821

openmc/cell.py

@@ -80,11 +80,11 @@ class Cell(object):
         If the cell is filled with a universe, this array specifies a vector
         that is used to translate (shift) the universe.
     paths : list of str
-        The paths traversed through the CSG tree to reach each cell instance
+        The paths traversed through the CSG tree to reach each cell
+        instance. This property is initialized by calling the
+        :meth:`Geometry.determine_paths` method.
     num_instances : int
-        The number of instances of this cell throughout the geometry. This
-        property is initialized by calling the
-        :meth:`Geometry.count_cell_instances` method.
+        The number of instances of this cell throughout the geometry.
     volume : float
         Volume of the cell in cm^3. This can either be set manually or
         calculated in a stochastic volume calculation and added via the

openmc/geometry.py

@@ -43,7 +43,7 @@ class Geometry(object):
     def root_universe(self, root_universe):
         check_type('root universe', root_universe, openmc.Universe)
         self._root_universe = root_universe
-        self.determine_paths()
+        self._determine_paths()
 
     def add_volume_information(self, volume_calc):
         """Add volume information from a stochastic volume calculation.
@@ -114,7 +114,6 @@ class Geometry(object):
         Parameters
         ----------
         path : str
-
             The path traversed through the CSG tree to reach a cell or material
             instance. For example, 'u0->c10->l20(2,2,1)->u5->c5' would indicate
             the cell instance whose first level is universe 0 and cell 10,
@@ -441,10 +440,14 @@ class Geometry(object):
         lattices.sort(key=lambda x: x.id)
         return lattices
 
-    def determine_paths(self):
-        """Count the number of instances for each cell in the Geometry, and
-        record the count in the :attr:`Cell.num_instances` properties."""
+    def _determine_paths(self):
+        """Determine paths through CSG tree for cells and materials.
 
+        This method recursively traverses the CSG tree to determine each unique
+        path that reaches every cell and material. The paths are stored in the
+        :attr:`Cell.paths` and :attr:`Material.paths` attributes.
+
+        """
         # (Re-)initialize all cell instances to 0
         for cell in self.get_all_cells().values():
             cell._paths = []

openmc/lattice.py

@@ -372,7 +372,10 @@ class Lattice(object):
         Parameters
         ----------
         idx : Iterable of int
-            Lattice element indices in the :math:`(x,y,z)` coordinate system
+            Lattice element indices. For a rectangular lattice, the indices are
+            given in the :math:`(x,y)` or :math:`(x,y,z)` coordinate system. For
+            hexagonal lattices, they are given in the :math:`x,\alpha` or
+            :math:`x,\alpha,z` coordinate systems.
 
         Returns
         -------
@@ -392,7 +395,7 @@ class Lattice(object):
         Parameters
         ----------
         point : 3-tuple of float
-            Cartesian coordinatesof the point
+            Cartesian coordinates of the point
 
         Returns
         -------
@@ -537,6 +540,13 @@ class RectLattice(Lattice):
 
     @property
     def _natural_indices(self):
+        """Iterate over all possible (x,y) or (x,y,z) lattice element indices.
+
+        This property is used when constructing distributed cell and material
+        paths. Most importantly, the iteration order matches that used on the
+        Fortran side.
+
+        """
         if self.ndim == 2:
             nx, ny = self.shape
             return np.broadcast(*np.ogrid[:nx, :ny])
@@ -889,6 +899,14 @@ class HexLattice(Lattice):
 
     @property
     def _natural_indices(self):
+        """Iterate over all possible (x,alpha) or (x,alpha,z) lattice element
+        indices.
+
+        This property is used when constructing distributed cell and material
+        paths. Most importantly, the iteration order matches that used on the
+        Fortran side.
+
+        """
         r = self.num_rings
         if self.num_axial is None:
             for a in range(-r + 1, r):

openmc/material.py

@@ -75,10 +75,12 @@ class Material(object):
         Volume of the material in cm^3. This can either be set manually or
         calculated in a stochastic volume calculation and added via the
         :meth:`Material.add_volume_information` method.
+    paths : list of str
+        The paths traversed through the CSG tree to reach each material
+        instance. This property is initialized by calling the
+        :meth:`Geometry.determine_paths` method.
     num_instances : int
-        The number of instances of this material throughout the geometry. This
-        property is initialized by calling the
-        :meth:`Geometry.count_material_instances` method.
+        The number of instances of this material throughout the geometry.
 
     """
 

src/geometry.F90

@@ -1333,8 +1333,6 @@ contains
     n = size(univ % cells)
 
     do i = 1, n
-
-      ! get pointer to cell
       associate (c => cells(univ % cells(i)))
         c % instances = c % instances + 1
 

src/input_xml.F90

@@ -2020,7 +2020,7 @@ contains
 
     do i = 1, n_cells
       ! Get index in universes array
-      j = universe_dict%get_key(cells(i) % universe)
+      j = universe_dict % get_key(cells(i) % universe)
 
       ! Set the first zero entry in the universe cells array to the index in the
       ! global cells array