Rename max_splits to max_history_splits, set default value to 1.0e7 (#2954)

Co-authored-by: Patrick Shriwise <pshriwise@gmail.com>
Co-authored-by: Paul Romano <paul.k.romano@gmail.com>

docs/source/io_formats/settings.rst

@@ -285,10 +285,10 @@ then, OpenMC will only use up to the :math:`P_1` data.
     :ref:`energy_mode`.
 
 ------------------------
-``<max_splits>`` Element
+``<max_history_splits>`` Element
 ------------------------
 
-The ``<max_splits>`` element indicates the number of times a particle can split during a history.
+The ``<max_history_splits>`` element indicates the number of times a particle can split during a history.
 
   *Default*: 1000
 

include/openmc/settings.h

@@ -121,7 +121,8 @@ extern std::unordered_set<int>
   statepoint_batch; //!< Batches when state should be written
 extern std::unordered_set<int>
   source_write_surf_id; //!< Surface ids where sources will be written
-extern int max_splits; //!< maximum number of particle splits for weight windows
+extern int
+  max_history_splits; //!< maximum number of particle splits for weight windows
 extern int64_t max_surface_particles; //!< maximum number of particles to be
                                       //!< banked on surfaces per process
 extern TemperatureMethod

openmc/settings.py

@@ -116,7 +116,7 @@ class Settings:
         .. versionadded:: 0.14.1
     max_order : None or int
         Maximum scattering order to apply globally when in multi-group mode.
-    max_splits : int
+    max_history_splits : int
         Maximum number of times a particle can split during a history
 
         .. versionadded:: 0.13
@@ -358,7 +358,7 @@ class Settings:
         self._weight_windows_on = None
         self._weight_windows_file = None
         self._weight_window_checkpoints = {}
-        self._max_splits = None
+        self._max_history_splits = None
         self._max_tracks = None
 
         self._random_ray = {}
@@ -1007,14 +1007,18 @@ class Settings:
         self._weight_window_checkpoints = weight_window_checkpoints
 
     @property
-    def max_splits(self) -> int:
-        return self._max_splits
+    def max_splits(self):
+        raise AttributeError('max_splits has been deprecated. Please use max_history_splits instead')
 
-    @max_splits.setter
-    def max_splits(self, value: int):
+    @property
+    def max_history_splits(self) -> int:
+        return self._max_history_splits
+
+    @max_history_splits.setter
+    def max_history_splits(self, value: int):
         cv.check_type('maximum particle splits', value, Integral)
         cv.check_greater_than('max particle splits', value, 0)
-        self._max_splits = value
+        self._max_history_splits = value
 
     @property
     def max_tracks(self) -> int:
@@ -1472,10 +1476,10 @@ class Settings:
             subelement = ET.SubElement(element, "surface")
             subelement.text = str(self._weight_window_checkpoints['surface']).lower()
 
-    def _create_max_splits_subelement(self, root):
-        if self._max_splits is not None:
-            elem = ET.SubElement(root, "max_splits")
-            elem.text = str(self._max_splits)
+    def _create_max_history_splits_subelement(self, root):
+        if self._max_history_splits is not None:
+            elem = ET.SubElement(root, "max_history_splits")
+            elem.text = str(self._max_history_splits)
 
     def _create_max_tracks_subelement(self, root):
         if self._max_tracks is not None:
@@ -1834,10 +1838,10 @@ class Settings:
                 value = value in ('true', '1')
                 self.weight_window_checkpoints[key] = value
 
-    def _max_splits_from_xml_element(self, root):
-        text = get_text(root, 'max_splits')
+    def _max_history_splits_from_xml_element(self, root):
+        text = get_text(root, 'max_history_splits')
         if text is not None:
-            self.max_splits = int(text)
+            self.max_history_splits = int(text)
 
     def _max_tracks_from_xml_element(self, root):
         text = get_text(root, 'max_tracks')
@@ -1915,7 +1919,7 @@ class Settings:
         self._create_weight_window_generators_subelement(element, mesh_memo)
         self._create_weight_windows_file_element(element)
         self._create_weight_window_checkpoints_subelement(element)
-        self._create_max_splits_subelement(element)
+        self._create_max_history_splits_subelement(element)
         self._create_max_tracks_subelement(element)
         self._create_random_ray_subelement(element)
 
@@ -2019,7 +2023,7 @@ class Settings:
         settings._weight_windows_from_xml_element(elem, meshes)
         settings._weight_window_generators_from_xml_element(elem, meshes)
         settings._weight_window_checkpoints_from_xml_element(elem)
-        settings._max_splits_from_xml_element(elem)
+        settings._max_history_splits_from_xml_element(elem)
         settings._max_tracks_from_xml_element(elem)
         settings._random_ray_from_xml_element(elem)
 

src/finalize.cpp

@@ -91,8 +91,8 @@ int openmc_finalize()
   settings::max_lost_particles = 10;
   settings::max_order = 0;
   settings::max_particles_in_flight = 100000;
-  settings::max_particle_events = 1000000;
-  settings::max_splits = 1000;
+  settings::max_particle_events = 1'000'000;
+  settings::max_history_splits = 10'000'000;
   settings::max_tracks = 1000;
   settings::max_write_lost_particles = -1;
   settings::n_log_bins = 8000;

src/settings.cpp

@@ -107,7 +107,7 @@ int max_order {0};
 int n_log_bins {8000};
 int n_batches;
 int n_max_batches;
-int max_splits {1000};
+int max_history_splits {10'000'000};
 int max_tracks {1000};
 ResScatMethod res_scat_method {ResScatMethod::rvs};
 double res_scat_energy_min {0.01};
@@ -981,8 +981,9 @@ void read_settings_xml(pugi::xml_node root)
     weight_windows_on = get_node_value_bool(root, "weight_windows_on");
   }
 
-  if (check_for_node(root, "max_splits")) {
-    settings::max_splits = std::stoi(get_node_value(root, "max_splits"));
+  if (check_for_node(root, "max_history_splits")) {
+    settings::max_history_splits =
+      std::stoi(get_node_value(root, "max_history_splits"));
   }
 
   if (check_for_node(root, "max_tracks")) {

src/weight_windows.cpp

@@ -102,7 +102,7 @@ void apply_weight_windows(Particle& p)
   // the window
   if (weight > weight_window.upper_weight) {
     // do not further split the particle if above the limit
-    if (p.n_split() >= settings::max_splits)
+    if (p.n_split() >= settings::max_history_splits)
       return;
 
     double n_split = std::ceil(weight / weight_window.upper_weight);

tests/regression_tests/weightwindows/generators/test.py

@@ -22,7 +22,7 @@ def test_ww_generator(run_in_tmpdir):
     model.settings.particles = 500
     model.settings.batches = 5
     model.settings.run_mode = 'fixed source'
-    model.settings.max_splits = 100
+    model.settings.max_history_splits = 100
 
     mesh = openmc.RegularMesh.from_domain(model.geometry.root_universe)
     energy_bounds = np.linspace(0.0, 1e6, 70)

tests/regression_tests/weightwindows/inputs_true.dat

@@ -70,7 +70,7 @@
       <max_split>10</max_split>
       <weight_cutoff>1e-38</weight_cutoff>
     </weight_windows>
-    <max_splits>200</max_splits>
+    <max_history_splits>200</max_history_splits>
   </settings>
   <tallies>
     <mesh id="1">

tests/regression_tests/weightwindows/test.py

@@ -48,7 +48,7 @@ def model():
     settings.run_mode = 'fixed source'
     settings.particles = 200
     settings.batches = 2
-    settings.max_splits = 200
+    settings.max_history_splits = 200
     settings.photon_transport = True
     space = Point((0.001, 0.001, 0.001))
     energy = Discrete([14E6], [1.0])

tests/unit_tests/weightwindows/test.py

@@ -94,7 +94,7 @@ def model():
     settings.run_mode = 'fixed source'
     settings.particles = 500
     settings.batches = 2
-    settings.max_splits = 100
+    settings.max_history_splits = 100
     settings.photon_transport = True
     space = Point((0.001, 0.001, 0.001))
     energy = Discrete([14E6], [1.0])

tests/unit_tests/weightwindows/test_ww_gen.py

@@ -55,7 +55,7 @@ def model():
         run_mode='fixed source',
         particles=100,
         batches=10,
-        max_splits=10,
+        max_history_splits=10,
         survival_biasing=False
     )