def _nanvar(a, axis=None, dtype=None, out=None, ddof=0,
keepdims=False):
# Using array() instead of asanyarray() because the former always
# makes a copy, which is important due to the copyto() action later
arr = array(a, subok=True)
mask = isnan(arr)
# First compute the mean, saving 'rcount' for reuse later
if dtype is None and (issubdtype(arr.dtype, nt.integer) or
issubdtype(arr.dtype, nt.bool_)):
arrmean = um.add.reduce(arr, axis=axis, dtype='f8', keepdims=True)
else:
mu.copyto(arr, 0.0, where=mask)
arrmean = um.add.reduce(arr, axis=axis, dtype=dtype,
keepdims=True)
rcount = (~mask).sum(axis=axis, keepdims=True)
if isinstance(arrmean, mu.ndarray):
arrmean = um.true_divide(arrmean, rcount,
out=arrmean, casting='unsafe', subok=False)
else:
arrmean = arrmean / float(rcount)
# arr - arrmean
x = arr - arrmean
mu.copyto(x, 0.0, where=mask)
# (arr - arrmean) ** 2
if issubdtype(arr.dtype, nt.complex_):
x = um.multiply(x, um.conjugate(x), out=x).real
else:
x = um.multiply(x, x, out=x)
# add.reduce((arr - arrmean) ** 2, axis)
ret = um.add.reduce(x, axis=axis, dtype=dtype, out=out,
keepdims=keepdims)
# add.reduce((arr - arrmean) ** 2, axis) / (n - ddof)
if not keepdims and isinstance(rcount, mu.ndarray):
rcount = rcount.squeeze(axis=axis)
rcount -= ddof
if isinstance(ret, mu.ndarray):
ret = um.true_divide(ret, rcount,
out=ret, casting='unsafe', subok=False)
else:
ret = ret / float(rcount)
return ret
def _nanmean(a, axis=None, dtype=None, out=None, keepdims=False):
# Using array() instead of asanyarray() because the former always
# makes a copy, which is important due to the copyto() action later
arr = array(a, subok=True)
mask = isnan(arr)
# Cast bool, unsigned int, and int to float64
if dtype is None and (issubdtype(arr.dtype, nt.integer) or
issubdtype(arr.dtype, nt.bool_)):
ret = um.add.reduce(arr, axis=axis, dtype='f8',
out=out, keepdims=keepdims)
else:
mu.copyto(arr, 0.0, where=mask)
ret = um.add.reduce(arr, axis=axis, dtype=dtype,
out=out, keepdims=keepdims)
rcount = (~mask).sum(axis=axis)
if isinstance(ret, mu.ndarray):
ret = um.true_divide(ret, rcount,
out=ret, casting='unsafe', subok=False)
else:
ret = ret / float(rcount)
return ret
