[ENH] OWSilhouettePlot: displays average silhouette

Orange/widgets/visualize/owsilhouetteplot.py

@@ -136,16 +136,17 @@ def __init__(self):
         self._silhouette = None  # type: Optional[np.ndarray]
         self._silplot = None     # type: Optional[SilhouettePlot]
 
-        controllayout = self.controlArea.layout()
-        assert isinstance(controllayout, QVBoxLayout)
+        info_box = gui.vBox(self.controlArea, "Info")
+        self.avg_silhouette_label = gui.widgetLabel(info_box, "")
+        self._update_avg_silhouette()
+
         self._distances_gui_box = distbox = gui.widgetBox(
-            None, "Distance"
+            self.controlArea, "Distance"
         )
         self._distances_gui_cb = gui.comboBox(
             distbox, self, "distance_idx",
             items=[name for name, _ in OWSilhouettePlot.Distances],
             orientation=Qt.Horizontal, callback=self._invalidate_distances)
-        controllayout.addWidget(distbox)
 
         box = gui.vBox(self.controlArea, "Grouping")
         self.cluster_var_model = itemmodels.VariableListModel(
@@ -177,6 +178,7 @@ def __init__(self):
         ibox.setFixedWidth(ibox.sizeHint().width())
         warning.setVisible(False)
 
+
         gui.rubber(self.controlArea)
 
         gui.auto_send(self.buttonsArea, self, "auto_commit")
@@ -292,6 +294,7 @@ def clear(self):
         self._clear_scene()
         self.Error.clear()
         self.Warning.clear()
+        self._update_avg_silhouette()  # Update the average silhouette display
 
     def _clear_scene(self):
         # Clear the graphics scene and associated objects
@@ -340,6 +343,14 @@ def _ensure_matrix(self):
             else:
                 assert False, "invalid state"
 
+    def _update_avg_silhouette(self):
+        if self._silhouette is not None and len(self._silhouette) > 0:
+            avg_score = np.mean(self._silhouette)
+            self.avg_silhouette_label.setText(
+                f"Average Silhouette: {avg_score:.4f}")
+        else:
+            self.avg_silhouette_label.setText("Average Silhouette: N/A")
+
     def _update(self):
         # Update/recompute the effective distances and scores as required.
         self._clear_messages()
@@ -384,6 +395,8 @@ def _update(self):
                 self.Warning.nan_distances(
                     count_nandist, s="s" if count_nandist > 1 else "")
 
+        self._update_avg_silhouette()  # Update the average silhouette display
+
     def _reset_all(self):
         self._mask = None
         self._silhouette = None

Orange/widgets/visualize/tests/test_owsilhouetteplot.py

@@ -302,6 +302,18 @@ def test_migration(self):
         self.assertEqual(context.values["cluster_var"], ("cfoo", 101))
         self.assertNotIn("annotation_var_idx", values)
 
+    def test_average_silhouette_score(self):
+        data = Table("brown-selected")
+        self.send_signal(self.widget.Inputs.data, data)
+        self.assertEqual(self.widget.avg_silhouette_label.text(),
+                        "Average Silhouette: 0.4692")
+        self.send_signal(self.widget.Inputs.data, None)
+        self.assertEqual(self.widget.avg_silhouette_label.text(),
+                        "Average Silhouette: N/A")
+        self.send_signal(self.widget.Inputs.data, data)
+        self.assertEqual(self.widget.avg_silhouette_label.text(), 
+                        "Average Silhouette: 0.4692")
+
 
 if __name__ == "__main__":
     unittest.main()