- make the minimum number of events in a workspace a configuration pa…

…rameter

- filter out workspaces with too few events before applying dead-time correction
- add user docs on advanced parameters

docs/user/advanced_parameters.rst

@@ -0,0 +1,15 @@
+.. _advanced_parameters:
+
+Advanced parameters
+===================
+
+Advanced parameters are only configurable in the local configuration file
+``~/.config/.refredm.conf``.
+
+``nbr_events_min``
+------------------
+
+Default: 100
+
+During loading of data files and direct beam files, any polarization cross-section event workspaces
+with number of events below this cut-off will be ignored.

docs/user/index.rst

@@ -9,3 +9,4 @@ TODO
    :maxdepth: 2
 
    dead_time_correction
+   advanced_parameters

reflectivity_ui/interfaces/configuration.py

@@ -44,6 +44,9 @@ class Configuration(object):
     deadtime_tof_step = 100
     # Direct beam uses the same low res roi as the data run
     lock_direct_beam_y = False
+    # Number of events below which we throw away a workspace
+    # Note: not exposed in the UI, but can be modified in ~/.config/.refredm.conf
+    nbr_events_min = 100
 
     def __init__(self, settings=None):
         self.instrument = Instrument()
@@ -241,6 +244,9 @@ def to_q_settings(self, settings):
         settings.setValue("deadtime_value", self.deadtime_value)
         settings.setValue("deadtime_tof_step", self.deadtime_tof_step)
 
+        # Number of events below which we throw away a workspace
+        settings.setValue("nbr_events_min", self.nbr_events_min)
+
         # Off-specular options
         settings.setValue("off_spec_x_axis", self.off_spec_x_axis)
         settings.setValue("off_spec_slice", self.off_spec_slice)
@@ -346,6 +352,9 @@ def _verify_true(parameter, default):
         Configuration.deadtime_value = float(settings.value("deadtime_value", self.deadtime_value))
         Configuration.deadtime_tof_step = float(settings.value("deadtime_tof_step", self.deadtime_tof_step))
 
+        # Number of events below which we throw away a workspace
+        Configuration.nbr_events_min = int(settings.value("nbr_events_min", self.nbr_events_min))
+
         # Off-specular options
         self.off_spec_x_axis = int(settings.value("off_spec_x_axis", self.off_spec_x_axis))
         self.off_spec_slice = _verify_true("off_spec_slice", self.off_spec_slice)
@@ -403,6 +412,7 @@ def setup_default_values(cls):
         cls.deadtime_value = 4.2
         cls.deadtime_tof_step = 100
         cls.lock_direct_beam_y = False
+        cls.nbr_events_min = 100
 
 
 def get_direct_beam_low_res_roi(data_conf, direct_beam_conf):

reflectivity_ui/interfaces/data_handling/data_set.py

@@ -431,7 +431,7 @@ def load(self, update_parameters=True, progress=None):
 
             # Get rid of empty workspaces
             logging.info("Loading %s: %s events", str(channel), ws.getNumberEvents())
-            if ws.getNumberEvents() < N_EVENTS_CUTOFF:
+            if ws.getNumberEvents() < self.configuration.nbr_events_min:
                 logging.warning("Too few events for %s: %s", channel, ws.getNumberEvents())
                 continue
 

reflectivity_ui/interfaces/data_handling/instrument.py

@@ -212,7 +212,6 @@ def load_data(self, file_path, configuration=None):
         """
         fp_instance = FilePath(file_path)
         xs_list = list()
-        err_list = list()
         temp_workspace_root_name = "".join(random.sample(string.ascii_letters, 12))  # random string of 12 characters
         workspace_root_name = fp_instance.run_numbers(string_representation="short")
         for path in fp_instance.single_paths:
@@ -231,6 +230,8 @@ def load_data(self, file_path, configuration=None):
                     logging.warning("Could not filter data, using getDI")
                     ws = api.LoadEventNexus(Filename=path, OutputWorkspace="raw_events")
                     _path_xs_list = self.dummy_filter_cross_sections(ws, name_prefix=temp_workspace_root_name)
+                # Remove workspaces with too few events
+                _path_xs_list = self.remove_low_event_workspaces(_path_xs_list, configuration.nbr_events_min)
                 if configuration is not None and configuration.apply_deadtime:
                     # Load error events from the bank_error_events entry
                     err_ws = api.LoadErrorEventsNexus(path)
@@ -424,3 +425,28 @@ def integrate_detector(self, ws, specular=True):
         integrated = api.Integration(ws_summed)
         integrated = api.Transpose(integrated)
         return integrated
+
+    @staticmethod
+    def remove_low_event_workspaces(ws_list, nbr_events_cutoff):
+        """
+        Removes workspaces with number of events below the cutoff from a list of workspaces
+
+        Parameters
+        ----------
+        ws_list: list[EventWorkspace]
+        nbr_events_cutoff: int
+            Minimum number of events
+
+        Returns
+        -------
+        list[EventWorkspace]
+            Input list with low event workspaces removes
+        """
+        pruned_list = []
+        for ws in ws_list:
+            xs_name = ws.getRun()["cross_section_id"].value
+            if ws.getNumberEvents() < nbr_events_cutoff:
+                logging.warning("Too few events for %s: %s", xs_name, ws.getNumberEvents())
+            else:
+                pruned_list.append(ws)
+        return pruned_list

test/unit/reflectivity_ui/interfaces/data_handling/test_instrument.py

@@ -59,3 +59,26 @@ def PyExec(self):
     custom_value = 4
     ws_out = mantid_algorithm_exec(TestMantidAlgo, Value=custom_value, OutputWorkspace="output")
     assert ws_out.readY(0)[0] == custom_value
+
+
+@pytest.mark.datarepo
+def test_load_data_nbr_events_min(data_server):
+    """Test load data with one cross-section with too few events"""
+    conf = Configuration()
+    file_path = data_server.path_to("REF_M_40776")
+
+    # load with no cut-off on number of events
+    conf.nbr_events_min = 0
+    ws_list = conf.instrument.load_data(file_path, conf)
+    assert len(ws_list) == 3
+
+    # load with cut-off on number of events
+    conf.nbr_events_min = 100
+    ws_list = conf.instrument.load_data(file_path, conf)
+    assert len(ws_list) == 2
+
+    # test loading with dead-time correction
+    conf.nbr_events_min = 100
+    conf.apply_deadtime = True
+    ws_list = conf.instrument.load_data(file_path, conf)
+    assert len(ws_list) == 2