OWDataProjectionWidget: Return no coordinates when no valid data

Orange/widgets/visualize/tests/test_owprojectionwidget.py

@@ -1,6 +1,6 @@
 # Test methods with long descriptive names can omit docstrings
 # pylint: disable=missing-docstring
-from unittest.mock import patch
+from unittest.mock import patch, Mock
 
 import numpy as np
 
@@ -164,3 +164,12 @@ def test_too_many_labels(self):
 
         self.widget.graph.too_many_labels.emit(False)
         self.assertFalse(w.is_shown())
+
+    def test_get_coordinates_data(self):
+        self.widget.get_embedding = Mock(return_value=np.ones((10, 2)))
+        self.widget.valid_data = np.ones((10,), dtype=bool)
+        self.widget.valid_data[0] = False
+        self.assertIsNotNone(self.widget.get_coordinates_data())
+        self.assertEqual(len(self.widget.get_coordinates_data()[0]), 9)
+        self.widget.valid_data = np.zeros((10,), dtype=bool)
+        self.assertIsNone(self.widget.get_coordinates_data()[0])

Orange/widgets/visualize/tests/test_owscatterplot.py

@@ -735,6 +735,13 @@ def test_on_manual_change(self):
         selection = vizrank.rank_table.selectedIndexes()
         self.assertEqual(len(selection), 0)
 
+    def test_regression_line(self):
+        self.widget.graph.controls.show_reg_line.setChecked(True)
+        self.send_signal(self.widget.Inputs.data, self.data)
+        data = self.data.copy()
+        data[:, 0] = np.nan
+        self.send_signal(self.widget.Inputs.data, data)
+
 
 if __name__ == "__main__":
     import unittest

Orange/widgets/visualize/utils/widget.py

@@ -486,8 +486,9 @@ def get_embedding(self):
 
     def get_coordinates_data(self):
         embedding = self.get_embedding()
-        return embedding[self.valid_data].T[:2] if embedding is not None \
-            else (None, None)
+        if embedding is not None and len(embedding[self.valid_data]):
+            return embedding[self.valid_data].T
+        return None, None
 
     def setup_plot(self):
         self.graph.reset_graph()