Python numpy 模块，can_cast() 实例源码
我们从Python开源项目中，提取了以下40个代码示例，用于说明如何使用numpy.can_cast()。
def set_data(self, A):
"""
Set the image array
ACCEPTS: numpy/PIL Image A
"""
self._full_res = A
self._A = A
if (self._A.dtype != np.uint8 and
not np.can_cast(self._A.dtype, np.float)):
raise TypeError("Image data can not convert to float")
if (self._A.ndim not in (2, 3) or
(self._A.ndim == 3 and self._A.shape[-1] not in (3, 4))):
raise TypeError("Invalid dimensions for image data")
self._imcache = None
self._rgbacache = None
self._oldxslice = None
self._oldyslice = None
self._sx, self._sy = None, None
def fillna(self, value):
if not np.can_cast(value, self.dtype):
raise TypeError("fill value must match dtype of series")
return self.map_partitions(M.fillna, value, meta=self)
def print_cancast_table(ntypes):
print('X', end=' ')
for char in ntypes:
print(char, end=' ')
print()
for row in ntypes:
print(row, end=' ')
for col in ntypes:
print(int(np.can_cast(row, col)), end=' ')
print()
def __call__(self, a, b, *args, **kwargs):
"Execute the call behavior."
# Get the data
(da, db) = (getdata(a), getdata(b))
# Get the result
with np.errstate(divide='ignore', invalid='ignore'):
result = self.f(da, db, *args, **kwargs)
# Get the mask as a combination of the source masks and invalid
m = ~umath.isfinite(result)
m |= getmask(a)
m |= getmask(b)
# Apply the domain
domain = ufunc_domain.get(self.f, None)
if domain is not None:
m |= filled(domain(da, db), True)
# Take care of the scalar case first
if (not m.ndim):
if m:
return masked
else:
return result
# When the mask is True, put back da if possible
# any errors, just abort; impossible to guarantee masked values
try:
np.copyto(result, 0, casting='unsafe', where=m)
# avoid using "*" since this may be overlaid
masked_da = umath.multiply(m, da)
# only add back if it can be cast safely
if np.can_cast(masked_da.dtype, result.dtype, casting='safe'):
result += masked_da
except:
pass
# Transforms to a (subclass of) MaskedArray
masked_result = result.view(get_masked_subclass(a, b))
masked_result._mask = m
if isinstance(a, MaskedArray):
masked_result._update_from(a)
elif isinstance(b, MaskedArray):
masked_result._update_from(b)
return masked_result
def _get_reduce_op(ops, dtype):
for i in ops._ops:
if numpy.can_cast(dtype.type, i[0][0]):
return i
raise TypeError("Type is mismatched. %s(...), %s" % (ops.name, dtype.type))
def print_cancast_table(ntypes):
print('X', end=' ')
for char in ntypes:
print(char, end=' ')
print()
for row in ntypes:
print(row, end=' ')
for col in ntypes:
print(int(np.can_cast(row, col)), end=' ')
print()
def __call__(self, a, b, *args, **kwargs):
"Execute the call behavior."
# Get the data
(da, db) = (getdata(a), getdata(b))
# Get the result
with np.errstate(divide='ignore', invalid='ignore'):
result = self.f(da, db, *args, **kwargs)
# Get the mask as a combination of the source masks and invalid
m = ~umath.isfinite(result)
m |= getmask(a)
m |= getmask(b)
# Apply the domain
domain = ufunc_domain.get(self.f, None)
if domain is not None:
m |= filled(domain(da, db), True)
# Take care of the scalar case first
if (not m.ndim):
if m:
return masked
else:
return result
# When the mask is True, put back da if possible
# any errors, just abort; impossible to guarantee masked values
try:
np.copyto(result, 0, casting='unsafe', where=m)
# avoid using "*" since this may be overlaid
masked_da = umath.multiply(m, da)
# only add back if it can be cast safely
if np.can_cast(masked_da.dtype, result.dtype, casting='safe'):
result += masked_da
except:
pass
# Transforms to a (subclass of) MaskedArray
masked_result = result.view(get_masked_subclass(a, b))
masked_result._mask = m
if isinstance(a, MaskedArray):
masked_result._update_from(a)
elif isinstance(b, MaskedArray):
masked_result._update_from(b)
return masked_result
def copyto(dst, src, casting='same_kind', where=None):
"""Copies values from one array to another with broadcasting.
This function can be called for arrays on different devices. In this case,
casting, ``where``, and broadcasting is not supported, and an exception is
raised if these are used.
Args:
dst (cupy.ndarray): Target array.
src (cupy.ndarray): Source array.
casting (str): Casting rule. See :func:`numpy.can_cast` for detail.
where (cupy.ndarray of bool): If specified, this array acts as a mask,
and an element is copied only if the corresponding element of
``where`` is True.
.. seealso:: :func:`numpy.copyto`
"""
if not numpy.can_cast(src.dtype, dst.dtype, casting):
raise TypeError('Cannot cast %s to %s in %s casting mode' %
(src.dtype, dst.dtype, casting))
if dst.size == 0:
return
if where is None:
if _can_memcpy(dst, src):
dst.data.copy_from(src.data, src.nbytes)
else:
core.elementwise_copy(src, dst)
else:
core.elementwise_copy_where(src, where, dst)
def __init__(self, name, *dimensions, data=None, kind=None):
super(Field, self).__init__(name)
self.__name = name
self.dimensions = dimensions
if kind is None:
if data is None:
self.kind = COMPLEX
elif isinstance(data, (numpy.ndarray, numpy.number)):
self.kind = DTYPE_KINDS[data.dtype.kind]
elif isinstance(data, SCALAR_TYPES):
self.kind = SCALAR_KINDS[type(data)]
else:
assert kind in (REAL, COMPLEX)
self.kind = kind
dtype = DEFAULT_DTYPES[self.kind]
shape = tuple(d.grid.size for d in dimensions)
if data is None:
self.data = numpy.empty(shape, dtype)
elif isinstance(data, SCALAR_TYPES):
self.data = numpy.ones(shape, dtype) * numpy.array(data).astype(dtype)
elif isinstance(data, numpy.ndarray):
assert data.shape == shape
assert numpy.can_cast(data.dtype, dtype)
self.data = data.astype(dtype)
else:
raise ValueError
def replace(self, to_replace, value, inplace=False, filter=None,
regex=False, mgr=None):
to_replace_values = np.atleast_1d(to_replace)
if not np.can_cast(to_replace_values, bool):
return self
return super(BoolBlock, self).replace(to_replace, value,
inplace=inplace, filter=filter,
regex=regex, mgr=mgr)
def print_cancast_table(ntypes):
print('X', end=' ')
for char in ntypes:
print(char, end=' ')
print()
for row in ntypes:
print(row, end=' ')
for col in ntypes:
print(int(np.can_cast(row, col)), end=' ')
print()
def print_cancast_table(ntypes):
print('X', end=' ')
for char in ntypes:
print(char, end=' ')
print()
for row in ntypes:
print(row, end=' ')
for col in ntypes:
print(int(np.can_cast(row, col)), end=' ')
print()
def __call__(self, a, b, *args, **kwargs):
"Execute the call behavior."
# Get the data
(da, db) = (getdata(a), getdata(b))
# Get the result
with np.errstate(divide='ignore', invalid='ignore'):
result = self.f(da, db, *args, **kwargs)
# Get the mask as a combination of the source masks and invalid
m = ~umath.isfinite(result)
m |= getmask(a)
m |= getmask(b)
# Apply the domain
domain = ufunc_domain.get(self.f, None)
if domain is not None:
m |= filled(domain(da, db), True)
# Take care of the scalar case first
if (not m.ndim):
if m:
return masked
else:
return result
# When the mask is True, put back da if possible
# any errors, just abort; impossible to guarantee masked values
try:
np.copyto(result, 0, casting='unsafe', where=m)
# avoid using "*" since this may be overlaid
masked_da = umath.multiply(m, da)
# only add back if it can be cast safely
if np.can_cast(masked_da.dtype, result.dtype, casting='safe'):
result += masked_da
except:
pass
# Transforms to a (subclass of) MaskedArray
masked_result = result.view(get_masked_subclass(a, b))
masked_result._mask = m
masked_result._update_from(result)
return masked_result
def print_cancast_table(ntypes):
print('X', end=' ')
for char in ntypes:
print(char, end=' ')
print()
for row in ntypes:
print(row, end=' ')
for col in ntypes:
print(int(np.can_cast(row, col)), end=' ')
print()
def __call__(self, a, b, *args, **kwargs):
"Execute the call behavior."
# Get the data
(da, db) = (getdata(a), getdata(b))
# Get the result
with np.errstate(divide='ignore', invalid='ignore'):
result = self.f(da, db, *args, **kwargs)
# Get the mask as a combination of the source masks and invalid
m = ~umath.isfinite(result)
m |= getmask(a)
m |= getmask(b)
# Apply the domain
domain = ufunc_domain.get(self.f, None)
if domain is not None:
m |= filled(domain(da, db), True)
# Take care of the scalar case first
if (not m.ndim):
if m:
return masked
else:
return result
# When the mask is True, put back da if possible
# any errors, just abort; impossible to guarantee masked values
try:
np.copyto(result, 0, casting='unsafe', where=m)
# avoid using "*" since this may be overlaid
masked_da = umath.multiply(m, da)
# only add back if it can be cast safely
if np.can_cast(masked_da.dtype, result.dtype, casting='safe'):
result += masked_da
except:
pass
# Transforms to a (subclass of) MaskedArray
masked_result = result.view(get_masked_subclass(a, b))
masked_result._mask = m
if isinstance(a, MaskedArray):
masked_result._update_from(a)
elif isinstance(b, MaskedArray):
masked_result._update_from(b)
return masked_result
def print_cancast_table(ntypes):
print('X', end=' ')
for char in ntypes:
print(char, end=' ')
print()
for row in ntypes:
print(row, end=' ')
for col in ntypes:
print(int(np.can_cast(row, col)), end=' ')
print()
def __call__(self, a, b, *args, **kwargs):
"Execute the call behavior."
# Get the data
(da, db) = (getdata(a), getdata(b))
# Get the result
with np.errstate(divide='ignore', invalid='ignore'):
result = self.f(da, db, *args, **kwargs)
# Get the mask as a combination of the source masks and invalid
m = ~umath.isfinite(result)
m |= getmask(a)
m |= getmask(b)
# Apply the domain
domain = ufunc_domain.get(self.f, None)
if domain is not None:
m |= domain(da, db)
# Take care of the scalar case first
if (not m.ndim):
if m:
return masked
else:
return result
# When the mask is True, put back da if possible
# any errors, just abort; impossible to guarantee masked values
try:
np.copyto(result, 0, casting='unsafe', where=m)
# avoid using "*" since this may be overlaid
masked_da = umath.multiply(m, da)
# only add back if it can be cast safely
if np.can_cast(masked_da.dtype, result.dtype, casting='safe'):
result += masked_da
except:
pass
# Transforms to a (subclass of) MaskedArray
masked_result = result.view(get_masked_subclass(a, b))
masked_result._mask = m
if isinstance(a, MaskedArray):
masked_result._update_from(a)
elif isinstance(b, MaskedArray):
masked_result._update_from(b)
return masked_result
def perform(self, node, inp, out_):
x, i = inp
out, = out_
# Copy always implied by numpy advanced indexing semantic.
if out[0] is not None and out[0].shape == (len(i),) + x.shape[1:]:
o = out[0]
else:
o = None
# If i.dtype is more precise than numpy.intp (int32 on 32-bit machines,
# int64 on 64-bit machines), numpy may raise the following error:
# TypeError: array cannot be safely cast to required type.
# We need to check if values in i can fit in numpy.intp, because
# if they don't, that should be an error (no array can have that
# many elements on a 32-bit arch).
if i.dtype != numpy.intp:
i_ = theano._asarray(i, dtype=numpy.intp)
if not numpy.can_cast(i.dtype, numpy.intp):
# Check if there was actually an incorrect conversion
if numpy.any(i != i_):
raise IndexError(
'index contains values that are bigger '
'than the maximum array size on this system.', i)
i = i_
out[0] = x.take(i, axis=0, out=o)
def print_cancast_table(ntypes):
print('X', end=' ')
for char in ntypes:
print(char, end=' ')
print()
for row in ntypes:
print(row, end=' ')
for col in ntypes:
print(int(np.can_cast(row, col)), end=' ')
print()
def __call__(self, a, b, *args, **kwargs):
"Execute the call behavior."
# Get the data
(da, db) = (getdata(a), getdata(b))
# Get the result
with np.errstate(divide='ignore', invalid='ignore'):
result = self.f(da, db, *args, **kwargs)
# Get the mask as a combination of the source masks and invalid
m = ~umath.isfinite(result)
m |= getmask(a)
m |= getmask(b)
# Apply the domain
domain = ufunc_domain.get(self.f, None)
if domain is not None:
m |= filled(domain(da, db), True)
# Take care of the scalar case first
if (not m.ndim):
if m:
return masked
else:
return result
# When the mask is True, put back da if possible
# any errors, just abort; impossible to guarantee masked values
try:
np.copyto(result, 0, casting='unsafe', where=m)
# avoid using "*" since this may be overlaid
masked_da = umath.multiply(m, da)
# only add back if it can be cast safely
if np.can_cast(masked_da.dtype, result.dtype, casting='safe'):
result += masked_da
except:
pass
# Transforms to a (subclass of) MaskedArray
masked_result = result.view(get_masked_subclass(a, b))
masked_result._mask = m
if isinstance(a, MaskedArray):
masked_result._update_from(a)
elif isinstance(b, MaskedArray):
masked_result._update_from(b)
return masked_result
def require_dataset(self, name, shape, dtype, exact=False, **kwds):
""" Open a dataset, creating it if it doesn't exist.
If keyword "exact" is False (default), an existing dataset must have
the same shape and a conversion-compatible dtype to be returned. If
True, the shape and dtype must match exactly.
Other dataset keywords (see create_dataset) may be provided, but are
only used if a new dataset is to be created.
Raises TypeError if an incompatible object already exists, or if the
shape or dtype don't match according to the above rules.
"""
with phil:
if not name in self:
return self.create_dataset(name, *(shape, dtype), **kwds)
dset = self[name]
if not isinstance(dset, Dataset):
raise TypeError("Incompatible object (%s) already exists" % dset.__class__.__name__)
if not shape == dset.shape:
raise TypeError("Shapes do not match (existing %s vs new %s)" % (dset.shape, shape))
if exact:
if not dtype == dset.dtype:
raise TypeError("Datatypes do not exactly match (existing %s vs new %s)" % (dset.dtype, dtype))
elif not numpy.can_cast(dtype, dset.dtype):
raise TypeError("Datatypes cannot be safely cast (existing %s vs new %s)" % (dset.dtype, dtype))
return dset
def test_casting(self):
# Check that casting a structured array to change its byte order
# works
a = np.array([(1,)], dtype=[('a', '<i4')])
assert_(np.can_cast(a.dtype, [('a', '>i4')], casting='unsafe'))
b = a.astype([('a', '>i4')])
assert_equal(b, a.byteswap().newbyteorder())
assert_equal(a['a'][0], b['a'][0])
# Check that equality comparison works on structured arrays if
# they are 'equiv'-castable
a = np.array([(5, 42), (10, 1)], dtype=[('a', '>i4'), ('b', '<f8')])
b = np.array([(42, 5), (1, 10)], dtype=[('b', '>f8'), ('a', '<i4')])
assert_(np.can_cast(a.dtype, b.dtype, casting='equiv'))
assert_equal(a == b, [True, True])
# Check that 'equiv' casting can reorder fields and change byte
# order
assert_(np.can_cast(a.dtype, b.dtype, casting='equiv'))
c = a.astype(b.dtype, casting='equiv')
assert_equal(a == c, [True, True])
# Check that 'safe' casting can change byte order and up-cast
# fields
t = [('a', '<i8'), ('b', '>f8')]
assert_(np.can_cast(a.dtype, t, casting='safe'))
c = a.astype(t, casting='safe')
assert_equal((c == np.array([(5, 42), (10, 1)], dtype=t)),
[True, True])
# Check that 'same_kind' casting can change byte order and
# change field widths within a "kind"
t = [('a', '<i4'), ('b', '>f4')]
assert_(np.can_cast(a.dtype, t, casting='same_kind'))
c = a.astype(t, casting='same_kind')
assert_equal((c == np.array([(5, 42), (10, 1)], dtype=t)),
[True, True])
# Check that casting fails if the casting rule should fail on
# any of the fields
t = [('a', '>i8'), ('b', '<f4')]
assert_(not np.can_cast(a.dtype, t, casting='safe'))
assert_raises(TypeError, a.astype, t, casting='safe')
t = [('a', '>i2'), ('b', '<f8')]
assert_(not np.can_cast(a.dtype, t, casting='equiv'))
assert_raises(TypeError, a.astype, t, casting='equiv')
t = [('a', '>i8'), ('b', '<i2')]
assert_(not np.can_cast(a.dtype, t, casting='same_kind'))
assert_raises(TypeError, a.astype, t, casting='same_kind')
assert_(not np.can_cast(a.dtype, b.dtype, casting='no'))
assert_raises(TypeError, a.astype, b.dtype, casting='no')
# Check that non-'unsafe' casting can't change the set of field names
for casting in ['no', 'safe', 'equiv', 'same_kind']:
t = [('a', '>i4')]
assert_(not np.can_cast(a.dtype, t, casting=casting))
t = [('a', '>i4'), ('b', '<f8'), ('c', 'i4')]
assert_(not np.can_cast(a.dtype, t, casting=casting))
def __call__(self, a, b, *args, **kwargs):
"""
Execute the call behavior.
"""
# Get the data, as ndarray
(da, db) = (getdata(a), getdata(b))
# Get the result
with np.errstate():
np.seterr(divide='ignore', invalid='ignore')
result = self.f(da, db, *args, **kwargs)
# Get the mask for the result
(ma, mb) = (getmask(a), getmask(b))
if ma is nomask:
if mb is nomask:
m = nomask
else:
m = umath.logical_or(getmaskarray(a), mb)
elif mb is nomask:
m = umath.logical_or(ma, getmaskarray(b))
else:
m = umath.logical_or(ma, mb)
# Case 1. : scalar
if not result.ndim:
if m:
return masked
return result
# Case 2. : array
# Revert result to da where masked
if m is not nomask and m.any():
# any errors, just abort; impossible to guarantee masked values
try:
np.copyto(result, 0, casting='unsafe', where=m)
# avoid using "*" since this may be overlaid
masked_da = umath.multiply(m, da)
# only add back if it can be cast safely
if np.can_cast(masked_da.dtype, result.dtype, casting='safe'):
result += masked_da
except:
pass
# Transforms to a (subclass of) MaskedArray
masked_result = result.view(get_masked_subclass(a, b))
masked_result._mask = m
if isinstance(a, MaskedArray):
masked_result._update_from(a)
elif isinstance(b, MaskedArray):
masked_result._update_from(b)
return masked_result
def copyto(dst, src, casting='same_kind', where=None):
"""Copies values from one array to another with broadcasting.
This function can be called for arrays on different devices. In this case,
casting, ``where``, and broadcasting is not supported, and an exception is
raised if these are used.
Args:
dst (cupy.ndarray): Target array.
src (cupy.ndarray): Source array.
casting (str): Casting rule. See :func:`numpy.can_cast` for detail.
where (cupy.ndarray of bool): If specified, this array acts as a mask,
and an element is copied only if the corresponding element of
``where`` is True.
.. seealso:: :func:`numpy.copyto`
"""
src_type = type(src)
src_is_python_scalar = (src_type in six.integer_types or
src_type in (bool, float, complex))
if src_is_python_scalar:
src_dtype = numpy.dtype(type(src))
can_cast = numpy.can_cast(src, dst.dtype, casting)
else:
src_dtype = src.dtype
can_cast = numpy.can_cast(src_dtype, dst.dtype, casting)
if not can_cast:
raise TypeError('Cannot cast %s to %s in %s casting mode' %
(src_dtype, dst.dtype, casting))
if dst.size == 0:
return
if src_is_python_scalar:
dst.fill(src)
return
if where is None:
if _can_memcpy(dst, src):
dst.data.copy_from(src.data, src.nbytes)
else:
device = dst.device
with device:
if src.device != device:
src = src.copy()
core.elementwise_copy(src, dst)
else:
core.elementwise_copy_where(src, where, dst)
def set_dtype(self, value, check=True):
"""Change data type of the bin contents.
Allowed conversions:
- from integral to float types
- between the same category of type (float/integer)
- from float types to integer if weights are trivial
Parameters
----------
value: np.dtype or something convertible to it.
check: bool
If True (default), all values are checked against the limits
"""
# TODO: Refactor out?
# TODO? Deal with unsigned types
value = np.dtype(value)
if value == self.dtype:
return # No change
if value.kind in "iu":
type_info = np.iinfo(value)
elif value.kind == "f":
type_info = np.finfo(value)
else:
raise RuntimeError("Unsupported dtype. Only integer/floating-point types are supported.")
if np.can_cast(self.dtype, value):
pass # Ok
elif check:
if np.issubdtype(value, np.integer):
if self.dtype.kind == "f":
for array in (self._frequencies, self._errors2):
if np.any(array % 1.0):
raise RuntimeError("Data contain non-integer values.")
for array in (self._frequencies, self._errors2):
if np.any((array > type_info.max) | (array < type_info.min)):
raise RuntimeError("Data contain values outside the specified range.")
self._dtype = value
self._frequencies = self._frequencies.astype(value)
self._errors2 = self._errors2.astype(value)
self._missed = self._missed.astype(value)
def test_casting(self):
# Check that casting a structured array to change its byte order
# works
a = np.array([(1,)], dtype=[('a', '<i4')])
assert_(np.can_cast(a.dtype, [('a', '>i4')], casting='unsafe'))
b = a.astype([('a', '>i4')])
assert_equal(b, a.byteswap().newbyteorder())
assert_equal(a['a'][0], b['a'][0])
# Check that equality comparison works on structured arrays if
# they are 'equiv'-castable
a = np.array([(5, 42), (10, 1)], dtype=[('a', '>i4'), ('b', '<f8')])
b = np.array([(42, 5), (1, 10)], dtype=[('b', '>f8'), ('a', '<i4')])
assert_(np.can_cast(a.dtype, b.dtype, casting='equiv'))
assert_equal(a == b, [True, True])
# Check that 'equiv' casting can reorder fields and change byte
# order
assert_(np.can_cast(a.dtype, b.dtype, casting='equiv'))
c = a.astype(b.dtype, casting='equiv')
assert_equal(a == c, [True, True])
# Check that 'safe' casting can change byte order and up-cast
# fields
t = [('a', '<i8'), ('b', '>f8')]
assert_(np.can_cast(a.dtype, t, casting='safe'))
c = a.astype(t, casting='safe')
assert_equal((c == np.array([(5, 42), (10, 1)], dtype=t)),
[True, True])
# Check that 'same_kind' casting can change byte order and
# change field widths within a "kind"
t = [('a', '<i4'), ('b', '>f4')]
assert_(np.can_cast(a.dtype, t, casting='same_kind'))
c = a.astype(t, casting='same_kind')
assert_equal((c == np.array([(5, 42), (10, 1)], dtype=t)),
[True, True])
# Check that casting fails if the casting rule should fail on
# any of the fields
t = [('a', '>i8'), ('b', '<f4')]
assert_(not np.can_cast(a.dtype, t, casting='safe'))
assert_raises(TypeError, a.astype, t, casting='safe')
t = [('a', '>i2'), ('b', '<f8')]
assert_(not np.can_cast(a.dtype, t, casting='equiv'))
assert_raises(TypeError, a.astype, t, casting='equiv')
t = [('a', '>i8'), ('b', '<i2')]
assert_(not np.can_cast(a.dtype, t, casting='same_kind'))
assert_raises(TypeError, a.astype, t, casting='same_kind')
assert_(not np.can_cast(a.dtype, b.dtype, casting='no'))
assert_raises(TypeError, a.astype, b.dtype, casting='no')
# Check that non-'unsafe' casting can't change the set of field names
for casting in ['no', 'safe', 'equiv', 'same_kind']:
t = [('a', '>i4')]
assert_(not np.can_cast(a.dtype, t, casting=casting))
t = [('a', '>i4'), ('b', '<f8'), ('c', 'i4')]
assert_(not np.can_cast(a.dtype, t, casting=casting))
def __call__(self, a, b, *args, **kwargs):
"""
Execute the call behavior.
"""
# Get the data, as ndarray
(da, db) = (getdata(a), getdata(b))
# Get the result
with np.errstate():
np.seterr(divide='ignore', invalid='ignore')
result = self.f(da, db, *args, **kwargs)
# Get the mask for the result
(ma, mb) = (getmask(a), getmask(b))
if ma is nomask:
if mb is nomask:
m = nomask
else:
m = umath.logical_or(getmaskarray(a), mb)
elif mb is nomask:
m = umath.logical_or(ma, getmaskarray(b))
else:
m = umath.logical_or(ma, mb)
# Case 1. : scalar
if not result.ndim:
if m:
return masked
return result
# Case 2. : array
# Revert result to da where masked
if m is not nomask and m.any():
# any errors, just abort; impossible to guarantee masked values
try:
np.copyto(result, 0, casting='unsafe', where=m)
# avoid using "*" since this may be overlaid
masked_da = umath.multiply(m, da)
# only add back if it can be cast safely
if np.can_cast(masked_da.dtype, result.dtype, casting='safe'):
result += masked_da
except:
pass
# Transforms to a (subclass of) MaskedArray
masked_result = result.view(get_masked_subclass(a, b))
masked_result._mask = m
if isinstance(a, MaskedArray):
masked_result._update_from(a)
elif isinstance(b, MaskedArray):
masked_result._update_from(b)
return masked_result
def __init__(self, value, shape=None, dtype=None):
"""
Create a new lazy array.
`value` : may be an int, long, float, bool, NumPy array, iterator,
generator or a function, `f(i)` or `f(i,j)`, depending on the
dimensions of the array.
`f(i,j)` should return a single number when `i` and `j` are integers,
and a 1D array when either `i` or `j` or both is a NumPy array (in the
latter case the two arrays must have equal lengths).
"""
self.dtype = dtype
self.operations = []
if isinstance(value, basestring):
raise TypeError("An larray cannot be created from a string")
elif isinstance(value, larray):
if shape is not None and value.shape is not None:
assert shape == value.shape
self._shape = shape or value.shape
self.base_value = value.base_value
self.dtype = dtype or value.dtype
self.operations = value.operations # should deepcopy?
elif isinstance(value, collections.Sized): # False for numbers, generators, functions, iterators
if have_scipy and sparse.issparse(value): # For sparse matrices
self.dtype = dtype or value.dtype
elif not isinstance(value, numpy.ndarray):
value = numpy.array(value, dtype=dtype)
elif dtype is not None:
assert numpy.can_cast(value.dtype, dtype, casting='safe') # or could convert value to the provided dtype
if shape and value.shape != shape:
raise ValueError("Array has shape %s, value has shape %s" % (shape, value.shape))
self._shape = value.shape
self.base_value = value
else:
assert numpy.isreal(value) # also True for callables, generators, iterators
self._shape = shape
if dtype is None or isinstance(value, dtype):
self.base_value = value
else:
try:
self.base_value = dtype(value)
except TypeError:
self.base_value = value
def test_casting(self):
# Check that casting a structured array to change its byte order
# works
a = np.array([(1,)], dtype=[('a', '<i4')])
assert_(np.can_cast(a.dtype, [('a', '>i4')], casting='unsafe'))
b = a.astype([('a', '>i4')])
assert_equal(b, a.byteswap().newbyteorder())
assert_equal(a['a'][0], b['a'][0])
# Check that equality comparison works on structured arrays if
# they are 'equiv'-castable
a = np.array([(5, 42), (10, 1)], dtype=[('a', '>i4'), ('b', '<f8')])
b = np.array([(42, 5), (1, 10)], dtype=[('b', '>f8'), ('a', '<i4')])
assert_(np.can_cast(a.dtype, b.dtype, casting='equiv'))
assert_equal(a == b, [True, True])
# Check that 'equiv' casting can reorder fields and change byte
# order
assert_(np.can_cast(a.dtype, b.dtype, casting='equiv'))
c = a.astype(b.dtype, casting='equiv')
assert_equal(a == c, [True, True])
# Check that 'safe' casting can change byte order and up-cast
# fields
t = [('a', '<i8'), ('b', '>f8')]
assert_(np.can_cast(a.dtype, t, casting='safe'))
c = a.astype(t, casting='safe')
assert_equal((c == np.array([(5, 42), (10, 1)], dtype=t)),
[True, True])
# Check that 'same_kind' casting can change byte order and
# change field widths within a "kind"
t = [('a', '<i4'), ('b', '>f4')]
assert_(np.can_cast(a.dtype, t, casting='same_kind'))
c = a.astype(t, casting='same_kind')
assert_equal((c == np.array([(5, 42), (10, 1)], dtype=t)),
[True, True])
# Check that casting fails if the casting rule should fail on
# any of the fields
t = [('a', '>i8'), ('b', '<f4')]
assert_(not np.can_cast(a.dtype, t, casting='safe'))
assert_raises(TypeError, a.astype, t, casting='safe')
t = [('a', '>i2'), ('b', '<f8')]
assert_(not np.can_cast(a.dtype, t, casting='equiv'))
assert_raises(TypeError, a.astype, t, casting='equiv')
t = [('a', '>i8'), ('b', '<i2')]
assert_(not np.can_cast(a.dtype, t, casting='same_kind'))
assert_raises(TypeError, a.astype, t, casting='same_kind')
assert_(not np.can_cast(a.dtype, b.dtype, casting='no'))
assert_raises(TypeError, a.astype, b.dtype, casting='no')
# Check that non-'unsafe' casting can't change the set of field names
for casting in ['no', 'safe', 'equiv', 'same_kind']:
t = [('a', '>i4')]
assert_(not np.can_cast(a.dtype, t, casting=casting))
t = [('a', '>i4'), ('b', '<f8'), ('c', 'i4')]
assert_(not np.can_cast(a.dtype, t, casting=casting))
def test_datetime_casting_rules(self):
# Cannot cast safely/same_kind between timedelta and datetime
assert_(not np.can_cast('m8', 'M8', casting='same_kind'))
assert_(not np.can_cast('M8', 'm8', casting='same_kind'))
assert_(not np.can_cast('m8', 'M8', casting='safe'))
assert_(not np.can_cast('M8', 'm8', casting='safe'))
# Can cast safely/same_kind from integer to timedelta
assert_(np.can_cast('i8', 'm8', casting='same_kind'))
assert_(np.can_cast('i8', 'm8', casting='safe'))
# Cannot cast safely/same_kind from float to timedelta
assert_(not np.can_cast('f4', 'm8', casting='same_kind'))
assert_(not np.can_cast('f4', 'm8', casting='safe'))
# Cannot cast safely/same_kind from integer to datetime
assert_(not np.can_cast('i8', 'M8', casting='same_kind'))
assert_(not np.can_cast('i8', 'M8', casting='safe'))
# Cannot cast safely/same_kind from bool to datetime
assert_(not np.can_cast('b1', 'M8', casting='same_kind'))
assert_(not np.can_cast('b1', 'M8', casting='safe'))
# Can cast safely/same_kind from bool to timedelta
assert_(np.can_cast('b1', 'm8', casting='same_kind'))
assert_(np.can_cast('b1', 'm8', casting='safe'))
# Can cast datetime safely from months/years to days
assert_(np.can_cast('M8[M]', 'M8[D]', casting='safe'))
assert_(np.can_cast('M8[Y]', 'M8[D]', casting='safe'))
# Cannot cast timedelta safely from months/years to days
assert_(not np.can_cast('m8[M]', 'm8[D]', casting='safe'))
assert_(not np.can_cast('m8[Y]', 'm8[D]', casting='safe'))
# Can cast datetime same_kind from months/years to days
assert_(np.can_cast('M8[M]', 'M8[D]', casting='same_kind'))
assert_(np.can_cast('M8[Y]', 'M8[D]', casting='same_kind'))
# Can't cast timedelta same_kind from months/years to days
assert_(not np.can_cast('m8[M]', 'm8[D]', casting='same_kind'))
assert_(not np.can_cast('m8[Y]', 'm8[D]', casting='same_kind'))
# Can't cast datetime same_kind across the date/time boundary
assert_(not np.can_cast('M8[D]', 'M8[h]', casting='same_kind'))
assert_(not np.can_cast('M8[h]', 'M8[D]', casting='same_kind'))
# Can cast timedelta same_kind across the date/time boundary
assert_(np.can_cast('m8[D]', 'm8[h]', casting='same_kind'))
assert_(np.can_cast('m8[h]', 'm8[D]', casting='same_kind'))
# Cannot cast safely if the integer multiplier doesn't divide
assert_(not np.can_cast('M8[7h]', 'M8[3h]', casting='safe'))
assert_(not np.can_cast('M8[3h]', 'M8[6h]', casting='safe'))
# But can cast same_kind
assert_(np.can_cast('M8[7h]', 'M8[3h]', casting='same_kind'))
# Can cast safely if the integer multiplier does divide
assert_(np.can_cast('M8[6h]', 'M8[3h]', casting='safe'))
def __call__(self, a, b, *args, **kwargs):
"""
Execute the call behavior.
"""
# Get the data, as ndarray
(da, db) = (getdata(a), getdata(b))
# Get the result
with np.errstate():
np.seterr(divide='ignore', invalid='ignore')
result = self.f(da, db, *args, **kwargs)
# Get the mask for the result
(ma, mb) = (getmask(a), getmask(b))
if ma is nomask:
if mb is nomask:
m = nomask
else:
m = umath.logical_or(getmaskarray(a), mb)
elif mb is nomask:
m = umath.logical_or(ma, getmaskarray(b))
else:
m = umath.logical_or(ma, mb)
# Case 1. : scalar
if not result.ndim:
if m:
return masked
return result
# Case 2. : array
# Revert result to da where masked
if m is not nomask and m.any():
# any errors, just abort; impossible to guarantee masked values
try:
np.copyto(result, 0, casting='unsafe', where=m)
# avoid using "*" since this may be overlaid
masked_da = umath.multiply(m, da)
# only add back if it can be cast safely
if np.can_cast(masked_da.dtype, result.dtype, casting='safe'):
result += masked_da
except:
pass
# Transforms to a (subclass of) MaskedArray
masked_result = result.view(get_masked_subclass(a, b))
masked_result._mask = m
masked_result._update_from(result)
return masked_result
def test_casting(self):
# Check that casting a structured array to change its byte order
# works
a = np.array([(1,)], dtype=[('a', '<i4')])
assert_(np.can_cast(a.dtype, [('a', '>i4')], casting='unsafe'))
b = a.astype([('a', '>i4')])
assert_equal(b, a.byteswap().newbyteorder())
assert_equal(a['a'][0], b['a'][0])
# Check that equality comparison works on structured arrays if
# they are 'equiv'-castable
a = np.array([(5, 42), (10, 1)], dtype=[('a', '>i4'), ('b', '<f8')])
b = np.array([(42, 5), (1, 10)], dtype=[('b', '>f8'), ('a', '<i4')])
assert_(np.can_cast(a.dtype, b.dtype, casting='equiv'))
assert_equal(a == b, [True, True])
# Check that 'equiv' casting can reorder fields and change byte
# order
assert_(np.can_cast(a.dtype, b.dtype, casting='equiv'))
c = a.astype(b.dtype, casting='equiv')
assert_equal(a == c, [True, True])
# Check that 'safe' casting can change byte order and up-cast
# fields
t = [('a', '<i8'), ('b', '>f8')]
assert_(np.can_cast(a.dtype, t, casting='safe'))
c = a.astype(t, casting='safe')
assert_equal((c == np.array([(5, 42), (10, 1)], dtype=t)),
[True, True])
# Check that 'same_kind' casting can change byte order and
# change field widths within a "kind"
t = [('a', '<i4'), ('b', '>f4')]
assert_(np.can_cast(a.dtype, t, casting='same_kind'))
c = a.astype(t, casting='same_kind')
assert_equal((c == np.array([(5, 42), (10, 1)], dtype=t)),
[True, True])
# Check that casting fails if the casting rule should fail on
# any of the fields
t = [('a', '>i8'), ('b', '<f4')]
assert_(not np.can_cast(a.dtype, t, casting='safe'))
assert_raises(TypeError, a.astype, t, casting='safe')
t = [('a', '>i2'), ('b', '<f8')]
assert_(not np.can_cast(a.dtype, t, casting='equiv'))
assert_raises(TypeError, a.astype, t, casting='equiv')
t = [('a', '>i8'), ('b', '<i2')]
assert_(not np.can_cast(a.dtype, t, casting='same_kind'))
assert_raises(TypeError, a.astype, t, casting='same_kind')
assert_(not np.can_cast(a.dtype, b.dtype, casting='no'))
assert_raises(TypeError, a.astype, b.dtype, casting='no')
# Check that non-'unsafe' casting can't change the set of field names
for casting in ['no', 'safe', 'equiv', 'same_kind']:
t = [('a', '>i4')]
assert_(not np.can_cast(a.dtype, t, casting=casting))
t = [('a', '>i4'), ('b', '<f8'), ('c', 'i4')]
assert_(not np.can_cast(a.dtype, t, casting=casting))
def test_datetime_casting_rules(self):
# Cannot cast safely/same_kind between timedelta and datetime
assert_(not np.can_cast('m8', 'M8', casting='same_kind'))
assert_(not np.can_cast('M8', 'm8', casting='same_kind'))
assert_(not np.can_cast('m8', 'M8', casting='safe'))
assert_(not np.can_cast('M8', 'm8', casting='safe'))
# Can cast safely/same_kind from integer to timedelta
assert_(np.can_cast('i8', 'm8', casting='same_kind'))
assert_(np.can_cast('i8', 'm8', casting='safe'))
# Cannot cast safely/same_kind from float to timedelta
assert_(not np.can_cast('f4', 'm8', casting='same_kind'))
assert_(not np.can_cast('f4', 'm8', casting='safe'))
# Cannot cast safely/same_kind from integer to datetime
assert_(not np.can_cast('i8', 'M8', casting='same_kind'))
assert_(not np.can_cast('i8', 'M8', casting='safe'))
# Cannot cast safely/same_kind from bool to datetime
assert_(not np.can_cast('b1', 'M8', casting='same_kind'))
assert_(not np.can_cast('b1', 'M8', casting='safe'))
# Can cast safely/same_kind from bool to timedelta
assert_(np.can_cast('b1', 'm8', casting='same_kind'))
assert_(np.can_cast('b1', 'm8', casting='safe'))
# Can cast datetime safely from months/years to days
assert_(np.can_cast('M8[M]', 'M8[D]', casting='safe'))
assert_(np.can_cast('M8[Y]', 'M8[D]', casting='safe'))
# Cannot cast timedelta safely from months/years to days
assert_(not np.can_cast('m8[M]', 'm8[D]', casting='safe'))
assert_(not np.can_cast('m8[Y]', 'm8[D]', casting='safe'))
# Can cast datetime same_kind from months/years to days
assert_(np.can_cast('M8[M]', 'M8[D]', casting='same_kind'))
assert_(np.can_cast('M8[Y]', 'M8[D]', casting='same_kind'))
# Can't cast timedelta same_kind from months/years to days
assert_(not np.can_cast('m8[M]', 'm8[D]', casting='same_kind'))
assert_(not np.can_cast('m8[Y]', 'm8[D]', casting='same_kind'))
# Can't cast datetime same_kind across the date/time boundary
assert_(not np.can_cast('M8[D]', 'M8[h]', casting='same_kind'))
assert_(not np.can_cast('M8[h]', 'M8[D]', casting='same_kind'))
# Can cast timedelta same_kind across the date/time boundary
assert_(np.can_cast('m8[D]', 'm8[h]', casting='same_kind'))
assert_(np.can_cast('m8[h]', 'm8[D]', casting='same_kind'))
# Cannot cast safely if the integer multiplier doesn't divide
assert_(not np.can_cast('M8[7h]', 'M8[3h]', casting='safe'))
assert_(not np.can_cast('M8[3h]', 'M8[6h]', casting='safe'))
# But can cast same_kind
assert_(np.can_cast('M8[7h]', 'M8[3h]', casting='same_kind'))
# Can cast safely if the integer multiplier does divide
assert_(np.can_cast('M8[6h]', 'M8[3h]', casting='safe'))
def __call__(self, a, b, *args, **kwargs):
"""
Execute the call behavior.
"""
# Get the data, as ndarray
(da, db) = (getdata(a), getdata(b))
# Get the result
with np.errstate():
np.seterr(divide='ignore', invalid='ignore')
result = self.f(da, db, *args, **kwargs)
# Get the mask for the result
(ma, mb) = (getmask(a), getmask(b))
if ma is nomask:
if mb is nomask:
m = nomask
else:
m = umath.logical_or(getmaskarray(a), mb)
elif mb is nomask:
m = umath.logical_or(ma, getmaskarray(b))
else:
m = umath.logical_or(ma, mb)
# Case 1. : scalar
if not result.ndim:
if m:
return masked
return result
# Case 2. : array
# Revert result to da where masked
if m is not nomask and m.any():
# any errors, just abort; impossible to guarantee masked values
try:
np.copyto(result, 0, casting='unsafe', where=m)
# avoid using "*" since this may be overlaid
masked_da = umath.multiply(m, da)
# only add back if it can be cast safely
if np.can_cast(masked_da.dtype, result.dtype, casting='safe'):
result += masked_da
except:
pass
# Transforms to a (subclass of) MaskedArray
masked_result = result.view(get_masked_subclass(a, b))
masked_result._mask = m
masked_result._update_from(result)
return masked_result
def test_casting(self):
# Check that casting a structured array to change its byte order
# works
a = np.array([(1,)], dtype=[('a', '<i4')])
assert_(np.can_cast(a.dtype, [('a', '>i4')], casting='unsafe'))
b = a.astype([('a', '>i4')])
assert_equal(b, a.byteswap().newbyteorder())
assert_equal(a['a'][0], b['a'][0])
# Check that equality comparison works on structured arrays if
# they are 'equiv'-castable
a = np.array([(5, 42), (10, 1)], dtype=[('a', '>i4'), ('b', '<f8')])
b = np.array([(42, 5), (1, 10)], dtype=[('b', '>f8'), ('a', '<i4')])
assert_(np.can_cast(a.dtype, b.dtype, casting='equiv'))
assert_equal(a == b, [True, True])
# Check that 'equiv' casting can reorder fields and change byte
# order
assert_(np.can_cast(a.dtype, b.dtype, casting='equiv'))
c = a.astype(b.dtype, casting='equiv')
assert_equal(a == c, [True, True])
# Check that 'safe' casting can change byte order and up-cast
# fields
t = [('a', '<i8'), ('b', '>f8')]
assert_(np.can_cast(a.dtype, t, casting='safe'))
c = a.astype(t, casting='safe')
assert_equal((c == np.array([(5, 42), (10, 1)], dtype=t)),
[True, True])
# Check that 'same_kind' casting can change byte order and
# change field widths within a "kind"
t = [('a', '<i4'), ('b', '>f4')]
assert_(np.can_cast(a.dtype, t, casting='same_kind'))
c = a.astype(t, casting='same_kind')
assert_equal((c == np.array([(5, 42), (10, 1)], dtype=t)),
[True, True])
# Check that casting fails if the casting rule should fail on
# any of the fields
t = [('a', '>i8'), ('b', '<f4')]
assert_(not np.can_cast(a.dtype, t, casting='safe'))
assert_raises(TypeError, a.astype, t, casting='safe')
t = [('a', '>i2'), ('b', '<f8')]
assert_(not np.can_cast(a.dtype, t, casting='equiv'))
assert_raises(TypeError, a.astype, t, casting='equiv')
t = [('a', '>i8'), ('b', '<i2')]
assert_(not np.can_cast(a.dtype, t, casting='same_kind'))
assert_raises(TypeError, a.astype, t, casting='same_kind')
assert_(not np.can_cast(a.dtype, b.dtype, casting='no'))
assert_raises(TypeError, a.astype, b.dtype, casting='no')
# Check that non-'unsafe' casting can't change the set of field names
for casting in ['no', 'safe', 'equiv', 'same_kind']:
t = [('a', '>i4')]
assert_(not np.can_cast(a.dtype, t, casting=casting))
t = [('a', '>i4'), ('b', '<f8'), ('c', 'i4')]
assert_(not np.can_cast(a.dtype, t, casting=casting))
def __call__(self, a, b, *args, **kwargs):
"""
Execute the call behavior.
"""
# Get the data, as ndarray
(da, db) = (getdata(a), getdata(b))
# Get the result
with np.errstate():
np.seterr(divide='ignore', invalid='ignore')
result = self.f(da, db, *args, **kwargs)
# Get the mask for the result
(ma, mb) = (getmask(a), getmask(b))
if ma is nomask:
if mb is nomask:
m = nomask
else:
m = umath.logical_or(getmaskarray(a), mb)
elif mb is nomask:
m = umath.logical_or(ma, getmaskarray(b))
else:
m = umath.logical_or(ma, mb)
# Case 1. : scalar
if not result.ndim:
if m:
return masked
return result
# Case 2. : array
# Revert result to da where masked
if m is not nomask and m.any():
# any errors, just abort; impossible to guarantee masked values
try:
np.copyto(result, 0, casting='unsafe', where=m)
# avoid using "*" since this may be overlaid
masked_da = umath.multiply(m, da)
# only add back if it can be cast safely
if np.can_cast(masked_da.dtype, result.dtype, casting='safe'):
result += masked_da
except:
pass
# Transforms to a (subclass of) MaskedArray
masked_result = result.view(get_masked_subclass(a, b))
masked_result._mask = m
if isinstance(a, MaskedArray):
masked_result._update_from(a)
elif isinstance(b, MaskedArray):
masked_result._update_from(b)
return masked_result
def test_casting(self):
# Check that casting a structured array to change its byte order
# works
a = np.array([(1,)], dtype=[('a', '<i4')])
assert_(np.can_cast(a.dtype, [('a', '>i4')], casting='unsafe'))
b = a.astype([('a', '>i4')])
assert_equal(b, a.byteswap().newbyteorder())
assert_equal(a['a'][0], b['a'][0])
# Check that equality comparison works on structured arrays if
# they are 'equiv'-castable
a = np.array([(5, 42), (10, 1)], dtype=[('a', '>i4'), ('b', '<f8')])
b = np.array([(42, 5), (1, 10)], dtype=[('b', '>f8'), ('a', '<i4')])
assert_(np.can_cast(a.dtype, b.dtype, casting='equiv'))
assert_equal(a == b, [True, True])
# Check that 'equiv' casting can reorder fields and change byte
# order
# New in 1.12: This behavior changes in 1.13, test for dep warning
assert_(np.can_cast(a.dtype, b.dtype, casting='equiv'))
with assert_warns(FutureWarning):
c = a.astype(b.dtype, casting='equiv')
assert_equal(a == c, [True, True])
# Check that 'safe' casting can change byte order and up-cast
# fields
t = [('a', '<i8'), ('b', '>f8')]
assert_(np.can_cast(a.dtype, t, casting='safe'))
c = a.astype(t, casting='safe')
assert_equal((c == np.array([(5, 42), (10, 1)], dtype=t)),
[True, True])
# Check that 'same_kind' casting can change byte order and
# change field widths within a "kind"
t = [('a', '<i4'), ('b', '>f4')]
assert_(np.can_cast(a.dtype, t, casting='same_kind'))
c = a.astype(t, casting='same_kind')
assert_equal((c == np.array([(5, 42), (10, 1)], dtype=t)),
[True, True])
# Check that casting fails if the casting rule should fail on
# any of the fields
t = [('a', '>i8'), ('b', '<f4')]
assert_(not np.can_cast(a.dtype, t, casting='safe'))
assert_raises(TypeError, a.astype, t, casting='safe')
t = [('a', '>i2'), ('b', '<f8')]
assert_(not np.can_cast(a.dtype, t, casting='equiv'))
assert_raises(TypeError, a.astype, t, casting='equiv')
t = [('a', '>i8'), ('b', '<i2')]
assert_(not np.can_cast(a.dtype, t, casting='same_kind'))
assert_raises(TypeError, a.astype, t, casting='same_kind')
assert_(not np.can_cast(a.dtype, b.dtype, casting='no'))
assert_raises(TypeError, a.astype, b.dtype, casting='no')
# Check that non-'unsafe' casting can't change the set of field names
for casting in ['no', 'safe', 'equiv', 'same_kind']:
t = [('a', '>i4')]
assert_(not np.can_cast(a.dtype, t, casting=casting))
t = [('a', '>i4'), ('b', '<f8'), ('c', 'i4')]
assert_(not np.can_cast(a.dtype, t, casting=casting))
def require_dataset(self, name, shape=None, dtype=None, exact=False,
data=None, fillvalue=None):
if name not in self:
return self.create_dataset(
name,
shape=shape,
dtype=dtype,
data=data,
fillvalue=fillvalue
)
current_object = self[name]
if not isinstance(current_object, ds.Dataset):
raise TypeError(
"Incompatible object already exists: {}".format(
current_object.__class__.__name__
)
)
data, attrs, meta = ds._prepare_write(data, self.plugin_manager.dataset_plugins.write_order)
# TODO verify proper attributes
_assert_data_shape_dtype_match(data, shape, dtype)
shape, dtype = _data_to_shape_and_dtype(data, shape, dtype)
if not np.array_equal(shape, current_object.shape):
raise TypeError(
"Shapes do not match (existing {} vs "
"new {})".format(current_object.shape, shape)
)
if dtype != current_object.dtype:
if exact:
raise TypeError(
"Datatypes do not exactly match "
"existing {} vs new {})".format(current_object.dtype, dtype)
)
if not np.can_cast(dtype, current_object.dtype):
raise TypeError(
"Cannot safely cast from {} to {}".format(
dtype,
current_object.dtype
)
)
return current_object
def test_casting(self):
# Check that casting a structured array to change its byte order
# works
a = np.array([(1,)], dtype=[('a', '<i4')])
assert_(np.can_cast(a.dtype, [('a', '>i4')], casting='unsafe'))
b = a.astype([('a', '>i4')])
assert_equal(b, a.byteswap().newbyteorder())
assert_equal(a['a'][0], b['a'][0])
# Check that equality comparison works on structured arrays if
# they are 'equiv'-castable
a = np.array([(5, 42), (10, 1)], dtype=[('a', '>i4'), ('b', '<f8')])
b = np.array([(42, 5), (1, 10)], dtype=[('b', '>f8'), ('a', '<i4')])
assert_(np.can_cast(a.dtype, b.dtype, casting='equiv'))
assert_equal(a == b, [True, True])
# Check that 'equiv' casting can reorder fields and change byte
# order
assert_(np.can_cast(a.dtype, b.dtype, casting='equiv'))
c = a.astype(b.dtype, casting='equiv')
assert_equal(a == c, [True, True])
# Check that 'safe' casting can change byte order and up-cast
# fields
t = [('a', '<i8'), ('b', '>f8')]
assert_(np.can_cast(a.dtype, t, casting='safe'))
c = a.astype(t, casting='safe')
assert_equal((c == np.array([(5, 42), (10, 1)], dtype=t)),
[True, True])
# Check that 'same_kind' casting can change byte order and
# change field widths within a "kind"
t = [('a', '<i4'), ('b', '>f4')]
assert_(np.can_cast(a.dtype, t, casting='same_kind'))
c = a.astype(t, casting='same_kind')
assert_equal((c == np.array([(5, 42), (10, 1)], dtype=t)),
[True, True])
# Check that casting fails if the casting rule should fail on
# any of the fields
t = [('a', '>i8'), ('b', '<f4')]
assert_(not np.can_cast(a.dtype, t, casting='safe'))
assert_raises(TypeError, a.astype, t, casting='safe')
t = [('a', '>i2'), ('b', '<f8')]
assert_(not np.can_cast(a.dtype, t, casting='equiv'))
assert_raises(TypeError, a.astype, t, casting='equiv')
t = [('a', '>i8'), ('b', '<i2')]
assert_(not np.can_cast(a.dtype, t, casting='same_kind'))
assert_raises(TypeError, a.astype, t, casting='same_kind')
assert_(not np.can_cast(a.dtype, b.dtype, casting='no'))
assert_raises(TypeError, a.astype, b.dtype, casting='no')
# Check that non-'unsafe' casting can't change the set of field names
for casting in ['no', 'safe', 'equiv', 'same_kind']:
t = [('a', '>i4')]
assert_(not np.can_cast(a.dtype, t, casting=casting))
t = [('a', '>i4'), ('b', '<f8'), ('c', 'i4')]
assert_(not np.can_cast(a.dtype, t, casting=casting))
def __call__(self, a, b, *args, **kwargs):
"""
Execute the call behavior.
"""
# Get the data, as ndarray
(da, db) = (getdata(a), getdata(b))
# Get the result
with np.errstate():
np.seterr(divide='ignore', invalid='ignore')
result = self.f(da, db, *args, **kwargs)
# Get the mask for the result
(ma, mb) = (getmask(a), getmask(b))
if ma is nomask:
if mb is nomask:
m = nomask
else:
m = umath.logical_or(getmaskarray(a), mb)
elif mb is nomask:
m = umath.logical_or(ma, getmaskarray(b))
else:
m = umath.logical_or(ma, mb)
# Case 1. : scalar
if not result.ndim:
if m:
return masked
return result
# Case 2. : array
# Revert result to da where masked
if m is not nomask and m.any():
# any errors, just abort; impossible to guarantee masked values
try:
np.copyto(result, 0, casting='unsafe', where=m)
# avoid using "*" since this may be overlaid
masked_da = umath.multiply(m, da)
# only add back if it can be cast safely
if np.can_cast(masked_da.dtype, result.dtype, casting='safe'):
result += masked_da
except:
pass
# Transforms to a (subclass of) MaskedArray
masked_result = result.view(get_masked_subclass(a, b))
masked_result._mask = m
if isinstance(a, MaskedArray):
masked_result._update_from(a)
elif isinstance(b, MaskedArray):
masked_result._update_from(b)
return masked_result