diff --git a/numpy/ma/extras.py b/numpy/ma/extras.py index 0a60ea331787..44b6eb58bf0a 100644 --- a/numpy/ma/extras.py +++ b/numpy/ma/extras.py @@ -720,6 +720,13 @@ def _median(a, axis=None, out=None, overwrite_input=False): elif axis < 0: axis += asorted.ndim + if asorted.shape[axis] == 0: + # for empty axis integer indices fail so use slicing to get same result + # as median (which is mean of empty slice = nan) + indexer = [slice(None)] * asorted.ndim + indexer[axis] = slice(0, 0) + return np.ma.mean(asorted[indexer], axis=axis, out=out) + if asorted.ndim == 1: counts = count(asorted) idx, odd = divmod(count(asorted), 2) diff --git a/numpy/ma/tests/test_extras.py b/numpy/ma/tests/test_extras.py index 58ac46f534ad..3576a7b75698 100644 --- a/numpy/ma/tests/test_extras.py +++ b/numpy/ma/tests/test_extras.py @@ -1044,14 +1044,14 @@ def test_empty(self): # axis 0 and 1 b = np.ma.masked_array(np.array([], dtype=float, ndmin=2)) - assert_equal(np.median(a, axis=0), b) - assert_equal(np.median(a, axis=1), b) + assert_equal(np.ma.median(a, axis=0), b) + assert_equal(np.ma.median(a, axis=1), b) # axis 2 b = np.ma.masked_array(np.array(np.nan, dtype=float, ndmin=2)) with warnings.catch_warnings(record=True) as w: warnings.filterwarnings('always', '', RuntimeWarning) - assert_equal(np.median(a, axis=2), b) + assert_equal(np.ma.median(a, axis=2), b) assert_(w[0].category is RuntimeWarning) def test_object(self):