Use ma.testutils rather than a filter for warnings with NaN in

masked arrays in test_mlab

Author: jenshnielsen

lib/matplotlib/tests/test_mlab.py

@@ -6,6 +6,7 @@
 import tempfile
 
 from numpy.testing import assert_allclose, assert_array_equal
+import numpy.ma.testutils as matest
 import numpy as np
 from nose.tools import (assert_equal, assert_almost_equal, assert_not_equal,
                         assert_true, assert_raises)
@@ -2714,10 +2715,7 @@ def get_z(x, y):
     z_masked = np.ma.array(z, mask=[False, False, False, True, False])
     correct_zi_masked = np.ma.masked_where(xi + yi > 1.0, get_z(xi, yi))
     zi = mlab.griddata(x, y, z_masked, xi, yi, interp='linear')
-    with np.errstate(invalid='ignore'):
-        # The array contains a number of NaNs so suppress the
-        # numpy warnings here.
-        np.testing.assert_array_almost_equal(zi, correct_zi_masked)
+    matest.assert_array_almost_equal(zi, correct_zi_masked)
     np.testing.assert_array_equal(np.ma.getmask(zi),
                                   np.ma.getmask(correct_zi_masked))