Fix copy in Python 2

astrofrog · astrofrog · commit 44febe219666 · 2017-05-17T16:40:28.000+01:00
diff --git a/astropy/visualization/tests/test_interval.py b/astropy/visualization/tests/test_interval.py
@@ -41,7 +41,7 @@ def test_manual_zero_limit(self):
 
     def test_manual_defaults_with_nan(self):
         interval = ManualInterval()
-        data = self.data.copy()
+        data = np.copy(self.data)
         data[0] = np.nan
         vmin, vmax = interval.get_limits(self.data)
         np.testing.assert_allclose(vmin, -20)
