Added doc string to explain callables for derived channels

model_server/base/roiset.py

@@ -308,12 +308,28 @@ class RoiSet(object):
         return zi_st
 
 
-    def classify_by(self, name: str, channels: int, object_classification_model: InstanceSegmentationModel, derived_channel_functions: dict[callable] = None):
+    def classify_by(
+            self, name: str, channels: list[int],
+            object_classification_model: InstanceSegmentationModel,
+            derived_channel_functions: list[callable] = None
+    ):
+        """
+        Insert a column in RoiSet data table that associates each ROI with an integer class, determined by passing
+        specified inputs through an instance segmentation classifier.  Optionally derive additional inputs for object
+        classification by passing a raw input channel through one or more functions.
+
+        :param name: name of column to insert
+        :param channels: list of nc raw input channels to send to classifier
+        :param object_classification_model: InstanceSegmentation model object
+        :param derived_channel_functions: list of functions that each receive a PatchStack accessor with nc channels and
+            return a single-channel PatchStack accessor of the same shape
+        :return: None
+        """
 
         raw_acc = self.get_patches_acc(channels=channels, expanded=False, pad_to=None)  # all channels
-        if derived_channel_functions:
+        if derived_channel_functions is not None:
             mono_data = [raw_acc.get_one_channel_data(c).data for c in range(0, raw_acc.chroma)]
-            for k, fcn in derived_channel_functions.items():
+            for fcn in derived_channel_functions:
                 der = fcn(raw_acc) # returns patch stack
                 assert der.shape == mono_data[0].shape
                 mono_data.append(der.data)

tests/test_roiset.py

@@ -217,10 +217,10 @@ class TestRoiSetMonoProducts(BaseTestRoiSetMonoProducts, unittest.TestCase):
             'multiple_input_model',
             [0, 1],
             ModelWithDerivedInputs(),
-            derived_channel_functions={
-                'der1': lambda acc: PatchStack(2 * acc.data),
-                'der2': lambda acc: PatchStack(0.5 * acc.data)
-            }
+            derived_channel_functions=[
+                lambda acc: PatchStack(2 * acc.data),
+                lambda acc: PatchStack(0.5 * acc.data)
+            ]
         )
         self.assertTrue(all(roiset.get_df()['classify_by_multiple_input_model'].unique() == [3]))
         self.assertTrue(all(np.unique(roiset.object_class_maps['multiple_input_model'].data) == [0, 3]))