def test_keepdims(self):
mat = np.eye(3)
for axis in [None, 0, 1]:
tgt = np.median(mat, axis=axis, out=None, overwrite_input=False)
res = np.nanmedian(mat, axis=axis, out=None, overwrite_input=False)
assert_(res.ndim == tgt.ndim)
d = np.ones((3, 5, 7, 11))
# Randomly set some elements to NaN:
w = np.random.random((4, 200)) * np.array(d.shape)[:, None]
w = w.astype(np.intp)
d[tuple(w)] = np.nan
with suppress_warnings() as sup:
sup.filter(RuntimeWarning)
res = np.nanmedian(d, axis=None, keepdims=True)
assert_equal(res.shape, (1, 1, 1, 1))
res = np.nanmedian(d, axis=(0, 1), keepdims=True)
assert_equal(res.shape, (1, 1, 7, 11))
res = np.nanmedian(d, axis=(0, 3), keepdims=True)
assert_equal(res.shape, (1, 5, 7, 1))
res = np.nanmedian(d, axis=(1,), keepdims=True)
assert_equal(res.shape, (3, 1, 7, 11))
res = np.nanmedian(d, axis=(0, 1, 2, 3), keepdims=True)
assert_equal(res.shape, (1, 1, 1, 1))
res = np.nanmedian(d, axis=(0, 1, 3), keepdims=True)
assert_equal(res.shape, (1, 1, 7, 1))
def test_out(self):
mat = np.random.rand(3, 3)
nan_mat = np.insert(mat, [0, 2], np.nan, axis=1)
resout = np.zeros(3)
tgt = np.median(mat, axis=1)
res = np.nanmedian(nan_mat, axis=1, out=resout)
assert_almost_equal(res, resout)
assert_almost_equal(res, tgt)
# 0-d output:
resout = np.zeros(())
tgt = np.median(mat, axis=None)
res = np.nanmedian(nan_mat, axis=None, out=resout)
assert_almost_equal(res, resout)
assert_almost_equal(res, tgt)
res = np.nanmedian(nan_mat, axis=(0, 1), out=resout)
assert_almost_equal(res, resout)
assert_almost_equal(res, tgt)
def test_small_large(self):
# test the small and large code paths, current cutoff 400 elements
for s in [5, 20, 51, 200, 1000]:
d = np.random.randn(4, s)
# Randomly set some elements to NaN:
w = np.random.randint(0, d.size, size=d.size // 5)
d.ravel()[w] = np.nan
d[:,0] = 1. # ensure at least one good value
# use normal median without nans to compare
tgt = []
for x in d:
nonan = np.compress(~np.isnan(x), x)
tgt.append(np.median(nonan, overwrite_input=True))
assert_array_equal(np.nanmedian(d, axis=-1), tgt)
def _append_med(arr, pad_amt, num, axis=-1):
"""
Append `pad_amt` median values along `axis`.
Parameters
----------
arr : ndarray
Input array of arbitrary shape.
pad_amt : int
Amount of padding to append.
num : int
Depth into `arr` along `axis` to calculate median.
Range: [1, `arr.shape[axis]`] or None (entire axis)
axis : int
Axis along which to pad `arr`.
Returns
-------
padarr : ndarray
Output array, with `pad_amt` values appended along `axis`. The
appended region is the median of the final `num` values along `axis`.
"""
if pad_amt == 0:
return arr
# Equivalent to edge padding for single value, so do that instead
if num == 1:
return _append_edge(arr, pad_amt, axis)
# Use entire array if `num` is too large
if num is not None:
if num >= arr.shape[axis]:
num = None
# Slice a chunk from the edge to calculate stats on
if num is not None:
med_slice = _slice_last(arr.shape, num, axis=axis)
else:
med_slice = tuple(slice(None) for x in arr.shape)
# Extract slice, calculate median
med_chunk = np.median(arr[med_slice], axis=axis, keepdims=True)
_round_ifneeded(med_chunk, arr.dtype)
# Concatenate `arr` with `med_chunk`, extended along `axis` by `pad_amt`
return _do_append(arr, med_chunk.repeat(pad_amt, axis), axis=axis)
def test_result_values(self):
tgt = [np.median(d) for d in _rdat]
res = np.nanmedian(_ndat, axis=1)
assert_almost_equal(res, tgt)