make cell_ids, instances, and mat_ids properties

Author: kkiesling

openmc_plotter/plotmodel.py

@@ -124,7 +124,6 @@ def __init__(self, use_settings_pkl):
 
         # Cell/Material ID by coordinates
         self.ids = None
-        self.instances = None
 
         # Return values from id_map and property_map
         self.ids_map = None
@@ -282,10 +281,6 @@ def makePlot(self):
             self.ids_map = openmc.lib.id_map(cv.view_params)
             self.properties = openmc.lib.property_map(cv.view_params)
 
-        self.cell_ids = self.ids_map[:, :, 0]
-        self.instances = self.ids_map[:, :, 1]
-        self.mat_ids = self.ids_map[:, :, 2]
-
         # set model ids based on domain
         if cv.colorby == 'cell':
             self.ids = self.cell_ids
@@ -732,6 +727,19 @@ def _do_op(array, tally_value, ax=0):
 
         return image_data, extents, data_min, data_max
 
+    @property
+    def cell_ids(self):
+        return self.ids_map[:, :, 0]
+
+    @property
+    def instances(self):
+        return self.ids_map[:, :, 1]
+
+    @property
+    def mat_ids(self):
+        return self.ids_map[:, :, 2]
+
+
 class ViewParam(openmc.lib.plot._PlotBase):
     """Viewer settings that are needed for _PlotBase and are independent
     of all other plotter/model settings.