add warning for non-working interpolations; fixes #159

src/gui_qt/main/management.py

@@ -829,9 +829,23 @@ class UpperManagement(QtCore.QObject):
             new_x = self.data[new_axis[0]].x
 
         new_key = []
+        missed = []
         for ids in data_ids:
-            k = self.add(interpolate(self.data[ids], new_x, xlog=xlog, ylog=ylog, kind=mode, extrapolate=True))
+            try:
-            new_key.append(k)
+                k = self.add(interpolate(self.data[ids], new_x, xlog=xlog, ylog=ylog, kind=mode, extrapolate=True))
+                new_key.append(k)
+            except ValueError:
+                missed.append(self.data[ids].name)
+
+        if missed:
+            missed_str = '\n'.join(missed)
+            _ = QtWidgets.QMessageBox.warning(
+                QtWidgets.QWidget(),
+                'Interpolation failed',
+                f'Interpolation failed for the following sets:\n\n'
+                f'{missed_str}\n\n'
+                f'(Probably because of duplicate x values)'
+            )
 
         self.newData.emit(new_key, dest_graph)