def view_element_first_byte(x):
"""Construct an array viewing the first byte of each element of `x`"""
from numpy.lib.stride_tricks import DummyArray
interface = dict(x.__array_interface__)
interface['typestr'] = '|b1'
interface['descr'] = [('', '|b1')]
return np.asarray(DummyArray(interface, x))
def view_element_first_byte(x):
"""Construct an array viewing the first byte of each element of `x`"""
from numpy.lib.stride_tricks import DummyArray
interface = dict(x.__array_interface__)
interface["typestr"] = "|b1"
interface["descr"] = [("", "|b1")]
return np.asarray(DummyArray(interface, x))
def as_strided(x, shape=None, strides=None, subok=False):
""" Make an ndarray from the given array with the given shape and strides.
"""
# first convert input to array, possibly keeping subclass
x = np.array(x, copy=False, subok=subok)
interface = dict(x.__array_interface__)
if shape is not None:
interface['shape'] = tuple(shape)
if strides is not None:
interface['strides'] = tuple(strides)
array = np.asarray(DummyArray(interface, base=x))
if array.dtype.fields is None and x.dtype.fields is not None:
# This should only happen if x.dtype is [('', 'Vx')]
array.dtype = x.dtype
return _maybe_view_as_subclass(x, array)
def as_strided(x, shape=None, strides=None, subok=False):
""" Make an ndarray from the given array with the given shape and strides.
"""
# first convert input to array, possibly keeping subclass
x = np.array(x, copy=False, subok=subok)
interface = dict(x.__array_interface__)
if shape is not None:
interface['shape'] = tuple(shape)
if strides is not None:
interface['strides'] = tuple(strides)
array = np.asarray(DummyArray(interface, base=x))
# Make sure dtype is correct in case of custom dtype
if array.dtype.kind == 'V':
array.dtype = x.dtype
if type(x) is not type(array):
# if input was an ndarray subclass and subclasses were OK,
# then view the result as that subclass.
array = array.view(type=type(x))
# Since we have done something akin to a view from x, we should let
# the subclass finalize (if it has it implemented, i.e., is not None).
if array.__array_finalize__:
array.__array_finalize__(x)
return array
