Add post processing hook for index functions (closes #100)

climix/aggregators.py

@@ -27,6 +27,13 @@ class PointLocalAggregator(Aggregator):
     def post_process(self, collapsed_cube, data_result, coords, **kwargs):
         cube = super().post_process(collapsed_cube, data_result, coords,
                                     **kwargs)
+        try:
+            post_processor = self.index_function.post_process
+        except AttributeError:
+            # this index function does not require post processing
+            pass
+        else:
+            cube = post_processor(cube, data_result, coords, **kwargs)
         standard_name = self.output_metadata['standard_name']
         unit_standard_name = standard_name
         proposed_standard_name = self.output_metadata.get(

climix/index.py

@@ -19,7 +19,8 @@ class Index:
         coord_name = self.period.add_coord_categorisation(cube)
         sub_cube = cube.extract(self.period.constraint)
         self.index_function.prepare(sub_cube)
-        aggregated = sub_cube.aggregated_by(coord_name, self.aggregator)
+        aggregated = sub_cube.aggregated_by(coord_name, self.aggregator,
+                                            period=self.period)
         if sliced_mode:
             results = []
             for r in aggregated.slices_over(coord_name):