def _nanquantile_unchecked(a, q, axis=None, out=None, overwrite_input=False,
interpolation='linear', keepdims=np._NoValue):
"""Assumes that q is in [0, 1], and is an ndarray"""
# apply_along_axis in _nanpercentile doesn't handle empty arrays well,
# so deal them upfront
if a.size == 0:
return np.nanmean(a, axis, out=out, keepdims=keepdims)
r, k = function_base._ureduce(
a, func=_nanquantile_ureduce_func, q=q, axis=axis, out=out,
overwrite_input=overwrite_input, interpolation=interpolation
)
if keepdims and keepdims is not np._NoValue:
return r.reshape(q.shape + k)
else:
return r
def nanmedian(a, axis=None, out=None, overwrite_input=False, keepdims=np._NoValue):
"""
Compute the median along the specified axis, while ignoring NaNs.
Returns the median of the array elements.
.. versionadded:: 1.9.0
Parameters
----------
a : array_like
Input array or object that can be converted to an array.
axis : {int, sequence of int, None}, optional
Axis or axes along which the medians are computed. The default
is to compute the median along a flattened version of the array.
A sequence of axes is supported since version 1.9.0.
out : ndarray, optional
Alternative output array in which to place the result. It must
have the same shape and buffer length as the expected output,
but the type (of the output) will be cast if necessary.
overwrite_input : bool, optional
If True, then allow use of memory of input array `a` for
calculations. The input array will be modified by the call to
`median`. This will save memory when you do not need to preserve
the contents of the input array. Treat the input as undefined,
but it will probably be fully or partially sorted. Default is
False. If `overwrite_input` is ``True`` and `a` is not already an
`ndarray`, an error will be raised.
keepdims : bool, optional
If this is set to True, the axes which are reduced are left
in the result as dimensions with size one. With this option,
the result will broadcast correctly against the original `a`.
If this is anything but the default value it will be passed
through (in the special case of an empty array) to the
`mean` function of the underlying array. If the array is
a sub-class and `mean` does not have the kwarg `keepdims` this
will raise a RuntimeError.
Returns
-------
median : ndarray
A new array holding the result. If the input contains integers
or floats smaller than ``float64``, then the output data-type is
``np.float64``. Otherwise, the data-type of the output is the
same as that of the input. If `out` is specified, that array is
returned instead.
See Also
--------
mean, median, percentile
Notes
-----
Given a vector ``V`` of length ``N``, the median of ``V`` is the
middle value of a sorted copy of ``V``, ``V_sorted`` - i.e.,
``V_sorted[(N-1)/2]``, when ``N`` is odd and the average of the two
middle values of ``V_sorted`` when ``N`` is even.
Examples
--------
>>> a = np.array([[10.0, 7, 4], [3, 2, 1]])
>>> a[0, 1] = np.nan
>>> a
array([[ 10., nan, 4.],
[ 3., 2., 1.]])
>>> np.median(a)
nan
>>> np.nanmedian(a)
3.0
>>> np.nanmedian(a, axis=0)
array([ 6.5, 2., 2.5])
>>> np.median(a, axis=1)
array([ 7., 2.])
>>> b = a.copy()
>>> np.nanmedian(b, axis=1, overwrite_input=True)
array([ 7., 2.])
>>> assert not np.all(a==b)
>>> b = a.copy()
>>> np.nanmedian(b, axis=None, overwrite_input=True)
3.0
>>> assert not np.all(a==b)
"""
a = np.asanyarray(a)
# apply_along_axis in _nanmedian doesn't handle empty arrays well,
# so deal them upfront
if a.size == 0:
return np.nanmean(a, axis, out=out, keepdims=keepdims)
r, k = _ureduce(a, func=_nanmedian, axis=axis, out=out,
overwrite_input=overwrite_input)
if keepdims and keepdims is not np._NoValue:
return r.reshape(k)
else:
return r
def nanpercentile(a, q, axis=None, out=None, overwrite_input=False,
interpolation='linear', keepdims=np._NoValue):
"""
Compute the qth percentile of the data along the specified axis,
while ignoring nan values.
Returns the qth percentile(s) of the array elements.
.. versionadded:: 1.9.0
Parameters
----------
a : array_like
Input array or object that can be converted to an array.
q : float in range of [0,100] (or sequence of floats)
Percentile to compute, which must be between 0 and 100
inclusive.
axis : {int, sequence of int, None}, optional
Axis or axes along which the percentiles are computed. The
default is to compute the percentile(s) along a flattened
version of the array. A sequence of axes is supported since
version 1.9.0.
out : ndarray, optional
Alternative output array in which to place the result. It must
have the same shape and buffer length as the expected output,
but the type (of the output) will be cast if necessary.
overwrite_input : bool, optional
If True, then allow use of memory of input array `a` for
calculations. The input array will be modified by the call to
`percentile`. This will save memory when you do not need to
preserve the contents of the input array. In this case you
should not make any assumptions about the contents of the input
`a` after this function completes -- treat it as undefined.
Default is False. If `a` is not already an array, this parameter
will have no effect as `a` will be converted to an array
internally regardless of the value of this parameter.
interpolation : {'linear', 'lower', 'higher', 'midpoint', 'nearest'}
This optional parameter specifies the interpolation method to
use when the desired quantile lies between two data points
``i < j``:
* linear: ``i + (j - i) * fraction``, where ``fraction`` is
the fractional part of the index surrounded by ``i`` and
``j``.
* lower: ``i``.
* higher: ``j``.
* nearest: ``i`` or ``j``, whichever is nearest.
* midpoint: ``(i + j) / 2``.
keepdims : bool, optional
If this is set to True, the axes which are reduced are left in
the result as dimensions with size one. With this option, the
result will broadcast correctly against the original array `a`.
If this is anything but the default value it will be passed
through (in the special case of an empty array) to the
`mean` function of the underlying array. If the array is
a sub-class and `mean` does not have the kwarg `keepdims` this
will raise a RuntimeError.
Returns
-------
percentile : scalar or ndarray
If `q` is a single percentile and `axis=None`, then the result
is a scalar. If multiple percentiles are given, first axis of
the result corresponds to the percentiles. The other axes are
the axes that remain after the reduction of `a`. If the input
contains integers or floats smaller than ``float64``, the output
data-type is ``float64``. Otherwise, the output data-type is the
same as that of the input. If `out` is specified, that array is
returned instead.
See Also
--------
nanmean, nanmedian, percentile, median, mean
Notes
-----
Given a vector ``V`` of length ``N``, the ``q``-th percentile of
``V`` is the value ``q/100`` of the way from the minimum to the
maximum in a sorted copy of ``V``. The values and distances of
the two nearest neighbors as well as the `interpolation` parameter
will determine the percentile if the normalized ranking does not
match the location of ``q`` exactly. This function is the same as
the median if ``q=50``, the same as the minimum if ``q=0`` and the
same as the maximum if ``q=100``.
Examples
--------
>>> a = np.array([[10., 7., 4.], [3., 2., 1.]])
>>> a[0][1] = np.nan
>>> a
array([[ 10., nan, 4.],
[ 3., 2., 1.]])
>>> np.percentile(a, 50)
nan
>>> np.nanpercentile(a, 50)
3.5
>>> np.nanpercentile(a, 50, axis=0)
array([ 6.5, 2., 2.5])
>>> np.nanpercentile(a, 50, axis=1, keepdims=True)
array([[ 7.],
[ 2.]])
>>> m = np.nanpercentile(a, 50, axis=0)
>>> out = np.zeros_like(m)
>>> np.nanpercentile(a, 50, axis=0, out=out)
array([ 6.5, 2., 2.5])
>>> m
array([ 6.5, 2. , 2.5])
>>> b = a.copy()
>>> np.nanpercentile(b, 50, axis=1, overwrite_input=True)
array([ 7., 2.])
>>> assert not np.all(a==b)
"""
a = np.asanyarray(a)
q = np.asanyarray(q)
# apply_along_axis in _nanpercentile doesn't handle empty arrays well,
# so deal them upfront
if a.size == 0:
return np.nanmean(a, axis, out=out, keepdims=keepdims)
r, k = _ureduce(a, func=_nanpercentile, q=q, axis=axis, out=out,
overwrite_input=overwrite_input,
interpolation=interpolation)
if keepdims and keepdims is not np._NoValue:
return r.reshape(q.shape + k)
else:
return r
def nanpercentile(a,
q,
axis=None,
out=None,
overwrite_input=False,
interpolation='linear',
keepdims=False):
"""
Compute the qth percentile of the data along the specified axis, while
ignoring nan values.
Returns the qth percentile of the array elements.
Parameters
----------
a : array_like
Input array or object that can be converted to an array.
q : float in range of [0,100] (or sequence of floats)
Percentile to compute which must be between 0 and 100 inclusive.
axis : int or sequence of int, optional
Axis along which the percentiles are computed. The default (None)
is to compute the percentiles along a flattened version of the array.
A sequence of axes is supported since version 1.9.0.
out : ndarray, optional
Alternative output array in which to place the result. It must
have the same shape and buffer length as the expected output,
but the type (of the output) will be cast if necessary.
overwrite_input : bool, optional
If True, then allow use of memory of input array `a` for
calculations. The input array will be modified by the call to
percentile. This will save memory when you do not need to preserve
the contents of the input array. In this case you should not make
any assumptions about the content of the passed in array `a` after
this function completes -- treat it as undefined. Default is False.
Note that, if the `a` input is not already an array this parameter
will have no effect, `a` will be converted to an array internally
regardless of the value of this parameter.
interpolation : {'linear', 'lower', 'higher', 'midpoint', 'nearest'}
This optional parameter specifies the interpolation method to use,
when the desired quantile lies between two data points `i` and `j`:
* linear: `i + (j - i) * fraction`, where `fraction` is the
fractional part of the index surrounded by `i` and `j`.
* lower: `i`.
* higher: `j`.
* nearest: `i` or `j` whichever is nearest.
* midpoint: (`i` + `j`) / 2.
keepdims : bool, optional
If this is set to True, the axes which are reduced are left
in the result as dimensions with size one. With this option,
the result will broadcast correctly against the original `arr`.
Returns
-------
nanpercentile : scalar or ndarray
If a single percentile `q` is given and axis=None a scalar is
returned. If multiple percentiles `q` are given an array holding
the result is returned. The results are listed in the first axis.
(If `out` is specified, in which case that array is returned
instead). If the input contains integers, or floats of smaller
precision than 64, then the output data-type is float64. Otherwise,
the output data-type is the same as that of the input.
See Also
--------
nanmean, nanmedian, percentile, median, mean
Notes
-----
Given a vector V of length N, the q-th percentile of V is the q-th ranked
value in a sorted copy of V. The values and distances of the two
nearest neighbors as well as the `interpolation` parameter will
determine the percentile if the normalized ranking does not match q
exactly. This function is the same as the median if ``q=50``, the same
as the minimum if ``q=0``and the same as the maximum if ``q=100``.
Examples
--------
>>> a = np.array([[10., 7., 4.], [3., 2., 1.]])
>>> a[0][1] = np.nan
>>> a
array([[ 10., nan, 4.],
[ 3., 2., 1.]])
>>> np.percentile(a, 50)
nan
>>> np.nanpercentile(a, 50)
3.5
>>> np.nanpercentile(a, 50, axis=0)
array([[ 6.5, 4.5, 2.5]])
>>> np.nanpercentile(a, 50, axis=1)
array([[ 7.],
[ 2.]])
>>> m = np.nanpercentile(a, 50, axis=0)
>>> out = np.zeros_like(m)
>>> np.nanpercentile(a, 50, axis=0, out=m)
array([[ 6.5, 4.5, 2.5]])
>>> m
array([[ 6.5, 4.5, 2.5]])
>>> b = a.copy()
>>> np.nanpercentile(b, 50, axis=1, overwrite_input=True)
array([[ 7.],
[ 2.]])
>>> assert not np.all(a==b)
>>> b = a.copy()
>>> np.nanpercentile(b, 50, axis=None, overwrite_input=True)
array([ 3.5])
"""
a = np.asanyarray(a)
q = np.asanyarray(q)
# apply_along_axis in _nanpercentile doesn't handle empty arrays well,
# so deal them upfront
if a.size == 0:
return np.nanmean(a, axis, out=out, keepdims=keepdims)
r, k = _ureduce(a,
func=_nanpercentile,
q=q,
axis=axis,
out=out,
overwrite_input=overwrite_input,
interpolation=interpolation)
if keepdims:
if q.ndim == 0:
return r.reshape(k)
else:
return r.reshape([len(q)] + k)
else:
return r
