nan support in std_deg

wetb/utils/geometry.py

@@ -50,7 +50,7 @@ def std_deg(dir):
     std_deg : float
         standard deviation
     """
-    return deg(np.sqrt(1 - (np.mean(sind(dir)) ** 2 + np.mean(cosd(dir)) ** 2)))
+    return deg(np.sqrt(1 - (np.nanmean(sind(dir)) ** 2 + np.nanmean(cosd(dir)) ** 2)))
 
 
 def wsp_dir2uv(wsp, dir, dir_ref=None):

wetb/utils/tests/test_geometry.py

@@ -65,6 +65,9 @@ class TestGeometry(unittest.TestCase):
         self.assertEqual(std_deg(np.array([0, 0, 0])), 0)
         self.assertAlmostEqual(std_deg(np.array([0, 90, 180, 270])), 57.296, 2)
 
+    def test_std_deg_nan(self):
+        self.assertAlmostEqual(std_deg(np.array([0, 90, 180, 270, np.nan])), 57.296, 2)
+
     def test_wspdir2uv(self):
         u, v = wsp_dir2uv(np.array([1, 1, 1]), np.array([30, 0, 330]))
         np.testing.assert_array_almost_equal(u, [0.8660, 1, 0.8660], 3)