The following are code examples for showing how to use . They are extracted from open source Python projects. You can vote up the examples you like or vote down the exmaples you don’t like. You can also save this page to your account.
Example 1
def _broadcast_to(array, shape, subok, readonly):
shape = tuple(shape) if np.iterable(shape) else (shape,)
array = np.array(array, copy=False, subok=subok)
if not shape and array.shape:
raise ValueError('cannot broadcast a non-scalar to a scalar array')
if any(size < 0 for size in shape):
raise ValueError('all elements of broadcast shape must be non-'
'negative')
needs_writeable = not readonly and array.flags.writeable
extras = ['reduce_ok'] if needs_writeable else []
op_flag = 'readwrite' if needs_writeable else 'readonly'
broadcast = np.nditer(
(array,), flags=['multi_index', 'refs_ok', 'zerosize_ok'] + extras,
op_flags=[op_flag], itershape=shape, order='C').itviews[0]
result = _maybe_view_as_subclass(array, broadcast)
if needs_writeable and not result.flags.writeable:
result.flags.writeable = True
return result Example 2
def _broadcast_shape(*args):
"""Returns the shape of the ararys that would result from broadcasting the
supplied arrays against each other.
"""
if not args:
raise ValueError('must provide at least one argument')
# use the old-iterator because np.nditer does not handle size 0 arrays
# consistently
b = np.broadcast(*args[:32])
# unfortunately, it cannot handle 32 or more arguments directly
for pos in range(32, len(args), 31):
# ironically, np.broadcast does not properly handle np.broadcast
# objects (it treats them as scalars)
# use broadcasting to avoid allocating the full array
b = broadcast_to(0, b.shape)
b = np.broadcast(b, *args[pos:(pos + 31)])
return b.shape Example 3
def _broadcast_to(array, shape, subok, readonly):
shape = tuple(shape) if np.iterable(shape) else (shape,)
array = np.array(array, copy=False, subok=subok)
if not shape and array.shape:
raise ValueError('cannot broadcast a non-scalar to a scalar array')
if any(size < 0 for size in shape):
raise ValueError('all elements of broadcast shape must be non-'
'negative')
needs_writeable = not readonly and array.flags.writeable
extras = ['reduce_ok'] if needs_writeable else []
op_flag = 'readwrite' if needs_writeable else 'readonly'
broadcast = np.nditer(
(array,), flags=['multi_index', 'refs_ok', 'zerosize_ok'] + extras,
op_flags=[op_flag], itershape=shape, order='C').itviews[0]
result = _maybe_view_as_subclass(array, broadcast)
if needs_writeable and not result.flags.writeable:
result.flags.writeable = True
return result Example 4
def _broadcast_shape(*args):
"""Returns the shape of the ararys that would result from broadcasting the
supplied arrays against each other.
"""
if not args:
raise ValueError('must provide at least one argument')
# use the old-iterator because np.nditer does not handle size 0 arrays
# consistently
b = np.broadcast(*args[:32])
# unfortunately, it cannot handle 32 or more arguments directly
for pos in range(32, len(args), 31):
# ironically, np.broadcast does not properly handle np.broadcast
# objects (it treats them as scalars)
# use broadcasting to avoid allocating the full array
b = broadcast_to(0, b.shape)
b = np.broadcast(b, *args[pos:(pos + 31)])
return b.shape Example 5
def _broadcast_shape(*args):
"""Returns the shape of the ararys that would result from broadcasting the
supplied arrays against each other.
"""
if not args:
raise ValueError('must provide at least one argument')
if len(args) == 1:
# a single argument does not work with np.broadcast
return np.asarray(args[0]).shape
# use the old-iterator because np.nditer does not handle size 0 arrays
# consistently
b = np.broadcast(*args[:32])
# unfortunately, it cannot handle 32 or more arguments directly
for pos in range(32, len(args), 31):
# ironically, np.broadcast does not properly handle np.broadcast
# objects (it treats them as scalars)
# use broadcasting to avoid allocating the full array
b = broadcast_to(0, b.shape)
b = np.broadcast(b, *args[pos:(pos + 31)])
return b.shape Example 6
def broadcast_shape(shp1, shp2):
"""Broadcast the shape of those arrays
Parameters
----------
shp1 : tuple
shape of array 1
shp2 : tuple
shape of array 2
Returns
-------
tuple
shape resulting from broadcasting two arrays using numpy rules
Raises
------
ValueError
Arrays cannot be broadcasted
"""
try:
return np.broadcast(np.empty(shp1), np.empty(shp2)).shape
except ValueError:
raise ValueError("Arrays cannot be broadcasted - %s and %s " % (str(shp1), str(shp2))) Example 7
def _broadcast_to(array, shape, subok, readonly):
shape = tuple(shape) if np.iterable(shape) else (shape,)
array = np.array(array, copy=False, subok=subok)
if not shape and array.shape:
raise ValueError('cannot broadcast a non-scalar to a scalar array')
if any(size < 0 for size in shape):
raise ValueError('all elements of broadcast shape must be non-'
'negative')
needs_writeable = not readonly and array.flags.writeable
extras = ['reduce_ok'] if needs_writeable else []
op_flag = 'readwrite' if needs_writeable else 'readonly'
broadcast = np.nditer(
(array,), flags=['multi_index', 'refs_ok', 'zerosize_ok'] + extras,
op_flags=[op_flag], itershape=shape, order='C').itviews[0]
result = _maybe_view_as_subclass(array, broadcast)
if needs_writeable and not result.flags.writeable:
result.flags.writeable = True
return result Example 8
def _broadcast_shape(*args):
"""Returns the shape of the ararys that would result from broadcasting the
supplied arrays against each other.
"""
if not args:
raise ValueError('must provide at least one argument')
# use the old-iterator because np.nditer does not handle size 0 arrays
# consistently
b = np.broadcast(*args[:32])
# unfortunately, it cannot handle 32 or more arguments directly
for pos in range(32, len(args), 31):
# ironically, np.broadcast does not properly handle np.broadcast
# objects (it treats them as scalars)
# use broadcasting to avoid allocating the full array
b = broadcast_to(0, b.shape)
b = np.broadcast(b, *args[pos:(pos + 31)])
return b.shape Example 9
def _broadcast_to(array, shape, subok, readonly):
shape = tuple(shape) if np.iterable(shape) else (shape,)
array = np.array(array, copy=False, subok=subok)
if not shape and array.shape:
raise ValueError('cannot broadcast a non-scalar to a scalar array')
if any(size < 0 for size in shape):
raise ValueError('all elements of broadcast shape must be non-'
'negative')
needs_writeable = not readonly and array.flags.writeable
extras = ['reduce_ok'] if needs_writeable else []
op_flag = 'readwrite' if needs_writeable else 'readonly'
broadcast = np.nditer(
(array,), flags=['multi_index', 'refs_ok', 'zerosize_ok'] + extras,
op_flags=[op_flag], itershape=shape, order='C').itviews[0]
result = _maybe_view_as_subclass(array, broadcast)
if needs_writeable and not result.flags.writeable:
result.flags.writeable = True
return result Example 10
def _broadcast_shape(*args):
"""Returns the shape of the arrays that would result from broadcasting the
supplied arrays against each other.
"""
if not args:
raise ValueError('must provide at least one argument')
# use the old-iterator because np.nditer does not handle size 0 arrays
# consistently
b = np.broadcast(*args[:32])
# unfortunately, it cannot handle 32 or more arguments directly
for pos in range(32, len(args), 31):
# ironically, np.broadcast does not properly handle np.broadcast
# objects (it treats them as scalars)
# use broadcasting to avoid allocating the full array
b = broadcast_to(0, b.shape)
b = np.broadcast(b, *args[pos:(pos + 31)])
return b.shape Example 11
def _broadcast_to(array, shape, subok, readonly):
shape = tuple(shape) if np.iterable(shape) else (shape,)
array = np.array(array, copy=False, subok=subok)
if not shape and array.shape:
raise ValueError('cannot broadcast a non-scalar to a scalar array')
if any(size < 0 for size in shape):
raise ValueError('all elements of broadcast shape must be non-'
'negative')
needs_writeable = not readonly and array.flags.writeable
extras = ['reduce_ok'] if needs_writeable else []
op_flag = 'readwrite' if needs_writeable else 'readonly'
broadcast = np.nditer(
(array,), flags=['multi_index', 'refs_ok', 'zerosize_ok'] + extras,
op_flags=[op_flag], itershape=shape, order='C').itviews[0]
result = _maybe_view_as_subclass(array, broadcast)
if needs_writeable and not result.flags.writeable:
result.flags.writeable = True
return result Example 12
def _broadcast_shape(*args):
"""Returns the shape of the ararys that would result from broadcasting the
supplied arrays against each other.
"""
if not args:
raise ValueError('must provide at least one argument')
# use the old-iterator because np.nditer does not handle size 0 arrays
# consistently
b = np.broadcast(*args[:32])
# unfortunately, it cannot handle 32 or more arguments directly
for pos in range(32, len(args), 31):
# ironically, np.broadcast does not properly handle np.broadcast
# objects (it treats them as scalars)
# use broadcasting to avoid allocating the full array
b = broadcast_to(0, b.shape)
b = np.broadcast(b, *args[pos:(pos + 31)])
return b.shape Example 13
def test_broadcast_in_args(self):
# gh-5881
arrs = [np.empty((6, 7)), np.empty((5, 6, 1)), np.empty((7,)),
np.empty((5, 1, 7))]
mits = [np.broadcast(*arrs),
np.broadcast(np.broadcast(*arrs[:2]), np.broadcast(*arrs[2:])),
np.broadcast(arrs[0], np.broadcast(*arrs[1:-1]), arrs[-1])]
for mit in mits:
assert_equal(mit.shape, (5, 6, 7))
assert_equal(mit.nd, 3)
assert_equal(mit.numiter, 4)
for a, ia in zip(arrs, mit.iters):
assert_(a is ia.base) Example 14
def test_broadcast_single_arg(self):
# gh-6899
arrs = [np.empty((5, 6, 7))]
mit = np.broadcast(*arrs)
assert_equal(mit.shape, (5, 6, 7))
assert_equal(mit.nd, 3)
assert_equal(mit.numiter, 1)
assert_(arrs[0] is mit.iters[0].base) Example 15
def test_number_of_arguments(self):
arr = np.empty((5,))
for j in range(35):
arrs = [arr] * j
if j < 1 or j > 32:
assert_raises(ValueError, np.broadcast, *arrs)
else:
mit = np.broadcast(*arrs)
assert_equal(mit.numiter, j) Example 16
def test_boolean_assignment_value_mismatch(self):
# A boolean assignment should fail when the shape of the values
# cannot be broadcast to the subscription. (see also gh-3458)
a = np.arange(4)
def f(a, v):
a[a > -1] = v
assert_raises(ValueError, f, a, [])
assert_raises(ValueError, f, a, [1, 2, 3])
assert_raises(ValueError, f, a[:1], [1, 2, 3]) Example 17
def setUp(self):
self.a = np.arange(np.prod([3, 1, 5, 6])).reshape(3, 1, 5, 6)
self.b = np.empty((3, 0, 5, 6))
self.complex_indices = ['skip', Ellipsis,
0,
# Boolean indices, up to 3-d for some special cases of eating up
# dimensions, also need to test all False
np.array(False),
np.array([True, False, False]),
np.array([[True, False], [False, True]]),
np.array([[[False, False], [False, False]]]),
# Some slices:
slice(-5, 5, 2),
slice(1, 1, 100),
slice(4, -1, -2),
slice(None, None, -3),
# Some Fancy indexes:
np.empty((0, 1, 1), dtype=np.intp), # empty and can be broadcast
np.array([0, 1, -2]),
np.array([[2], [0], [1]]),
np.array([[0, -1], [0, 1]], dtype=np.dtype('intp').newbyteorder()),
np.array([2, -1], dtype=np.int8),
np.zeros([1]*31, dtype=int), # trigger too large array.
np.array([0., 1.])] # invalid datatype
# Some simpler indices that still cover a bit more
self.simple_indices = [Ellipsis, None, -1, [1], np.array([True]), 'skip']
# Very simple ones to fill the rest:
self.fill_indices = [slice(None, None), 0] Example 18
def broadcast_to(array, shape, subok=False):
"""Broadcast an array to a new shape.
Parameters
----------
array : array_like
The array to broadcast.
shape : tuple
The shape of the desired array.
subok : bool, optional
If True, then sub-classes will be passed-through, otherwise
the returned array will be forced to be a base-class array (default).
Returns
-------
broadcast : array
A readonly view on the original array with the given shape. It is
typically not contiguous. Furthermore, more than one element of a
broadcasted array may refer to a single memory location.
Raises
------
ValueError
If the array is not compatible with the new shape according to NumPy's
broadcasting rules.
Notes
-----
.. versionadded:: 1.10.0
Examples
--------
>>> x = np.array([1, 2, 3])
>>> np.broadcast_to(x, (3, 3))
array([[1, 2, 3],
[1, 2, 3],
[1, 2, 3]])
"""
return _broadcast_to(array, shape, subok=subok, readonly=True) Example 19
def test_broadcast_in_args(self):
# gh-5881
arrs = [np.empty((6, 7)), np.empty((5, 6, 1)), np.empty((7,)),
np.empty((5, 1, 7))]
mits = [np.broadcast(*arrs),
np.broadcast(np.broadcast(*arrs[:2]), np.broadcast(*arrs[2:])),
np.broadcast(arrs[0], np.broadcast(*arrs[1:-1]), arrs[-1])]
for mit in mits:
assert_equal(mit.shape, (5, 6, 7))
assert_equal(mit.nd, 3)
assert_equal(mit.numiter, 4)
for a, ia in zip(arrs, mit.iters):
assert_(a is ia.base) Example 20
def test_broadcast_single_arg(self):
# gh-6899
arrs = [np.empty((5, 6, 7))]
mit = np.broadcast(*arrs)
assert_equal(mit.shape, (5, 6, 7))
assert_equal(mit.nd, 3)
assert_equal(mit.numiter, 1)
assert_(arrs[0] is mit.iters[0].base) Example 21
def test_number_of_arguments(self):
arr = np.empty((5,))
for j in range(35):
arrs = [arr] * j
if j < 1 or j > 32:
assert_raises(ValueError, np.broadcast, *arrs)
else:
mit = np.broadcast(*arrs)
assert_equal(mit.numiter, j) Example 22
def test_boolean_assignment_value_mismatch(self):
# A boolean assignment should fail when the shape of the values
# cannot be broadcast to the subscription. (see also gh-3458)
a = np.arange(4)
def f(a, v):
a[a > -1] = v
assert_raises(ValueError, f, a, [])
assert_raises(ValueError, f, a, [1, 2, 3])
assert_raises(ValueError, f, a[:1], [1, 2, 3]) Example 23
def setUp(self):
self.a = np.arange(np.prod([3, 1, 5, 6])).reshape(3, 1, 5, 6)
self.b = np.empty((3, 0, 5, 6))
self.complex_indices = ['skip', Ellipsis,
0,
# Boolean indices, up to 3-d for some special cases of eating up
# dimensions, also need to test all False
np.array(False),
np.array([True, False, False]),
np.array([[True, False], [False, True]]),
np.array([[[False, False], [False, False]]]),
# Some slices:
slice(-5, 5, 2),
slice(1, 1, 100),
slice(4, -1, -2),
slice(None, None, -3),
# Some Fancy indexes:
np.empty((0, 1, 1), dtype=np.intp), # empty and can be broadcast
np.array([0, 1, -2]),
np.array([[2], [0], [1]]),
np.array([[0, -1], [0, 1]], dtype=np.dtype('intp').newbyteorder()),
np.array([2, -1], dtype=np.int8),
np.zeros([1]*31, dtype=int), # trigger too large array.
np.array([0., 1.])] # invalid datatype
# Some simpler indices that still cover a bit more
self.simple_indices = [Ellipsis, None, -1, [1], np.array([True]), 'skip']
# Very simple ones to fill the rest:
self.fill_indices = [slice(None, None), 0] Example 24
def broadcast_to(array, shape, subok=False):
"""Broadcast an array to a new shape.
Parameters
----------
array : array_like
The array to broadcast.
shape : tuple
The shape of the desired array.
subok : bool, optional
If True, then sub-classes will be passed-through, otherwise
the returned array will be forced to be a base-class array (default).
Returns
-------
broadcast : array
A readonly view on the original array with the given shape. It is
typically not contiguous. Furthermore, more than one element of a
broadcasted array may refer to a single memory location.
Raises
------
ValueError
If the array is not compatible with the new shape according to NumPy's
broadcasting rules.
Notes
-----
.. versionadded:: 1.10.0
Examples
--------
>>> x = np.array([1, 2, 3])
>>> np.broadcast_to(x, (3, 3))
array([[1, 2, 3],
[1, 2, 3],
[1, 2, 3]])
"""
return _broadcast_to(array, shape, subok=subok, readonly=True) Example 25
def iterkeys(self,index):
#import pdb; pdb.set_trace()
if not isinstance(index,tuple) and self.shape[0] == 1:
index = (1,index)
if isinstance(index, int):
key = np.unravel_index(index-1, self.shape, order='F')
yield tuple(k+1 for k in key)
elif isinstance(index,slice):
index = range((index.start or 1)-1,
index.stop or np.prod(self.shape),
index.step or 1)
for key in np.transpose(np.unravel_index(index, self.shape, order='F')): # 0-based
yield tuple(k+1 for k in key)
elif isinstance(index,(list,np.ndarray)):
index = np.asarray(index)-1
for key in np.transpose(np.unravel_index(index, self.shape, order='F')):
yield tuple(k+1 for k in key)
else:
assert isinstance(index,tuple),index.__class__
indices = [] # 1-based
for i,ix in enumerate(index):
if isinstance(ix,slice):
indices.append(np.arange((ix.start or 1),
(ix.stop or self.shape[i]) + 1,
ix.step or 1,
dtype=int))
else:
indices.append(np.asarray(ix))
assert len(index) == 2
indices[0].shape = (-1,1)
for key in np.broadcast(*indices):
yield tuple(map(int,key)) Example 26
def test_broadcast_in_args(self):
# gh-5881
arrs = [np.empty((6, 7)), np.empty((5, 6, 1)), np.empty((7,)),
np.empty((5, 1, 7))]
mits = [np.broadcast(*arrs),
np.broadcast(np.broadcast(*arrs[:2]), np.broadcast(*arrs[2:])),
np.broadcast(arrs[0], np.broadcast(*arrs[1:-1]), arrs[-1])]
for mit in mits:
assert_equal(mit.shape, (5, 6, 7))
assert_equal(mit.nd, 3)
assert_equal(mit.numiter, 4)
for a, ia in zip(arrs, mit.iters):
assert_(a is ia.base) Example 27
def test_number_of_arguments(self):
arr = np.empty((5,))
for j in range(35):
arrs = [arr] * j
if j < 2 or j > 32:
assert_raises(ValueError, np.broadcast, *arrs)
else:
mit = np.broadcast(*arrs)
assert_equal(mit.numiter, j) Example 28
def test_boolean_assignment_value_mismatch(self):
# A boolean assignment should fail when the shape of the values
# cannot be broadcast to the subscription. (see also gh-3458)
a = np.arange(4)
def f(a, v):
a[a > -1] = v
assert_raises(ValueError, f, a, [])
assert_raises(ValueError, f, a, [1, 2, 3])
assert_raises(ValueError, f, a[:1], [1, 2, 3]) Example 29
def setUp(self):
self.a = np.arange(np.prod([3, 1, 5, 6])).reshape(3, 1, 5, 6)
self.b = np.empty((3, 0, 5, 6))
self.complex_indices = ['skip', Ellipsis,
0,
# Boolean indices, up to 3-d for some special cases of eating up
# dimensions, also need to test all False
np.array(False),
np.array([True, False, False]),
np.array([[True, False], [False, True]]),
np.array([[[False, False], [False, False]]]),
# Some slices:
slice(-5, 5, 2),
slice(1, 1, 100),
slice(4, -1, -2),
slice(None, None, -3),
# Some Fancy indexes:
np.empty((0, 1, 1), dtype=np.intp), # empty and can be broadcast
np.array([0, 1, -2]),
np.array([[2], [0], [1]]),
np.array([[0, -1], [0, 1]], dtype=np.dtype('intp').newbyteorder()),
np.array([2, -1], dtype=np.int8),
np.zeros([1]*31, dtype=int), # trigger too large array.
np.array([0., 1.])] # invalid datatype
# Some simpler indices that still cover a bit more
self.simple_indices = [Ellipsis, None, -1, [1], np.array([True]), 'skip']
# Very simple ones to fill the rest:
self.fill_indices = [slice(None, None), 0] Example 30
def _compare_index_result(self, arr, index, mimic_get, no_copy):
"""Compare mimicked result to indexing result.
"""
arr = arr.copy()
indexed_arr = arr[index]
assert_array_equal(indexed_arr, mimic_get)
# Check if we got a view, unless its a 0-sized or 0-d array.
# (then its not a view, and that does not matter)
if indexed_arr.size != 0 and indexed_arr.ndim != 0:
assert_(np.may_share_memory(indexed_arr, arr) == no_copy)
# Check reference count of the original array
if no_copy:
# refcount increases by one:
assert_equal(sys.getrefcount(arr), 3)
else:
assert_equal(sys.getrefcount(arr), 2)
# Test non-broadcast setitem:
b = arr.copy()
b[index] = mimic_get + 1000
if b.size == 0:
return # nothing to compare here...
if no_copy and indexed_arr.ndim != 0:
# change indexed_arr in-place to manipulate original:
indexed_arr += 1000
assert_array_equal(arr, b)
return
# Use the fact that the array is originally an arange:
arr.flat[indexed_arr.ravel()] += 1000
assert_array_equal(arr, b) Example 31
def shape_from_elems(*elems):
if len(elems) == 0:
return 1,
return np.broadcast(*[np.ones(elem.shape) for elem in elems]).shape Example 32
def Softmax(x):
# TODO make this numerically stable by shifting by max?
exp = Exp(x)
if len(x.shape) == 1: # workaround because numpy einsum can't broadcast? https://github.com/numpy/numpy/issues/9984
return exp / Einsum("i->", exp)
elif len(x.shape) == 2:
return exp / Einsum("bi,o->bo", exp, np.array([1]))
elif len(x.shape) == 3:
return exp / Einsum("abi,o->abo", exp, np.array([1]))
elif len(x.shape) == 4:
return exp / Einsum("abci,o->abco", exp, np.array([1]))
else:
raise ValueError("5D tensors not yet supported") Example 33
def test_broadcast_in_args(self):
# gh-5881
arrs = [np.empty((6, 7)), np.empty((5, 6, 1)), np.empty((7,)),
np.empty((5, 1, 7))]
mits = [np.broadcast(*arrs),
np.broadcast(np.broadcast(*arrs[:2]), np.broadcast(*arrs[2:])),
np.broadcast(arrs[0], np.broadcast(*arrs[1:-1]), arrs[-1])]
for mit in mits:
assert_equal(mit.shape, (5, 6, 7))
assert_equal(mit.nd, 3)
assert_equal(mit.numiter, 4)
for a, ia in zip(arrs, mit.iters):
assert_(a is ia.base) Example 34
def test_number_of_arguments(self):
arr = np.empty((5,))
for j in range(35):
arrs = [arr] * j
if j < 2 or j > 32:
assert_raises(ValueError, np.broadcast, *arrs)
else:
mit = np.broadcast(*arrs)
assert_equal(mit.numiter, j) Example 35
def test_boolean_assignment_value_mismatch(self):
# A boolean assignment should fail when the shape of the values
# cannot be broadcast to the subscription. (see also gh-3458)
a = np.arange(4)
def f(a, v):
a[a > -1] = v
assert_raises(ValueError, f, a, [])
assert_raises(ValueError, f, a, [1, 2, 3])
assert_raises(ValueError, f, a[:1], [1, 2, 3]) Example 36
def setUp(self):
self.a = np.arange(np.prod([3, 1, 5, 6])).reshape(3, 1, 5, 6)
self.b = np.empty((3, 0, 5, 6))
self.complex_indices = ['skip', Ellipsis,
0,
# Boolean indices, up to 3-d for some special cases of eating up
# dimensions, also need to test all False
np.array(False),
np.array([True, False, False]),
np.array([[True, False], [False, True]]),
np.array([[[False, False], [False, False]]]),
# Some slices:
slice(-5, 5, 2),
slice(1, 1, 100),
slice(4, -1, -2),
slice(None, None, -3),
# Some Fancy indexes:
np.empty((0, 1, 1), dtype=np.intp), # empty and can be broadcast
np.array([0, 1, -2]),
np.array([[2], [0], [1]]),
np.array([[0, -1], [0, 1]], dtype=np.dtype('intp').newbyteorder()),
np.array([2, -1], dtype=np.int8),
np.zeros([1]*31, dtype=int), # trigger too large array.
np.array([0., 1.])] # invalid datatype
# Some simpler indices that still cover a bit more
self.simple_indices = [Ellipsis, None, -1, [1], np.array([True]), 'skip']
# Very simple ones to fill the rest:
self.fill_indices = [slice(None, None), 0] Example 37
def _compare_index_result(self, arr, index, mimic_get, no_copy):
"""Compare mimicked result to indexing result.
"""
arr = arr.copy()
indexed_arr = arr[index]
assert_array_equal(indexed_arr, mimic_get)
# Check if we got a view, unless its a 0-sized or 0-d array.
# (then its not a view, and that does not matter)
if indexed_arr.size != 0 and indexed_arr.ndim != 0:
assert_(np.may_share_memory(indexed_arr, arr) == no_copy)
# Check reference count of the original array
if no_copy:
# refcount increases by one:
assert_equal(sys.getrefcount(arr), 3)
else:
assert_equal(sys.getrefcount(arr), 2)
# Test non-broadcast setitem:
b = arr.copy()
b[index] = mimic_get + 1000
if b.size == 0:
return # nothing to compare here...
if no_copy and indexed_arr.ndim != 0:
# change indexed_arr in-place to manipulate original:
indexed_arr += 1000
assert_array_equal(arr, b)
return
# Use the fact that the array is originally an arange:
arr.flat[indexed_arr.ravel()] += 1000
assert_array_equal(arr, b) Example 38
def broadcast_to(array, shape, subok=False):
"""Broadcast an array to a new shape.
Parameters
----------
array : array_like
The array to broadcast.
shape : tuple
The shape of the desired array.
subok : bool, optional
If True, then sub-classes will be passed-through, otherwise
the returned array will be forced to be a base-class array (default).
Returns
-------
broadcast : array
A readonly view on the original array with the given shape. It is
typically not contiguous. Furthermore, more than one element of a
broadcasted array may refer to a single memory location.
Raises
------
ValueError
If the array is not compatible with the new shape according to NumPy's
broadcasting rules.
Notes
-----
.. versionadded:: 1.10.0
Examples
--------
>>> x = np.array([1, 2, 3])
>>> np.broadcast_to(x, (3, 3))
array([[1, 2, 3],
[1, 2, 3],
[1, 2, 3]])
"""
return _broadcast_to(array, shape, subok=subok, readonly=True) Example 39
def test_broadcast_in_args(self):
# gh-5881
arrs = [np.empty((6, 7)), np.empty((5, 6, 1)), np.empty((7,)),
np.empty((5, 1, 7))]
mits = [np.broadcast(*arrs),
np.broadcast(np.broadcast(*arrs[:2]), np.broadcast(*arrs[2:])),
np.broadcast(arrs[0], np.broadcast(*arrs[1:-1]), arrs[-1])]
for mit in mits:
assert_equal(mit.shape, (5, 6, 7))
assert_equal(mit.nd, 3)
assert_equal(mit.numiter, 4)
for a, ia in zip(arrs, mit.iters):
assert_(a is ia.base) Example 40
def test_broadcast_single_arg(self):
# gh-6899
arrs = [np.empty((5, 6, 7))]
mit = np.broadcast(*arrs)
assert_equal(mit.shape, (5, 6, 7))
assert_equal(mit.nd, 3)
assert_equal(mit.numiter, 1)
assert_(arrs[0] is mit.iters[0].base) Example 41
def test_number_of_arguments(self):
arr = np.empty((5,))
for j in range(35):
arrs = [arr] * j
if j < 1 or j > 32:
assert_raises(ValueError, np.broadcast, *arrs)
else:
mit = np.broadcast(*arrs)
assert_equal(mit.numiter, j) Example 42
def test_boolean_assignment_value_mismatch(self):
# A boolean assignment should fail when the shape of the values
# cannot be broadcast to the subscription. (see also gh-3458)
a = np.arange(4)
def f(a, v):
a[a > -1] = v
assert_raises(ValueError, f, a, [])
assert_raises(ValueError, f, a, [1, 2, 3])
assert_raises(ValueError, f, a[:1], [1, 2, 3]) Example 43
def setUp(self):
self.a = np.arange(np.prod([3, 1, 5, 6])).reshape(3, 1, 5, 6)
self.b = np.empty((3, 0, 5, 6))
self.complex_indices = ['skip', Ellipsis,
0,
# Boolean indices, up to 3-d for some special cases of eating up
# dimensions, also need to test all False
np.array(False),
np.array([True, False, False]),
np.array([[True, False], [False, True]]),
np.array([[[False, False], [False, False]]]),
# Some slices:
slice(-5, 5, 2),
slice(1, 1, 100),
slice(4, -1, -2),
slice(None, None, -3),
# Some Fancy indexes:
np.empty((0, 1, 1), dtype=np.intp), # empty and can be broadcast
np.array([0, 1, -2]),
np.array([[2], [0], [1]]),
np.array([[0, -1], [0, 1]], dtype=np.dtype('intp').newbyteorder()),
np.array([2, -1], dtype=np.int8),
np.zeros([1]*31, dtype=int), # trigger too large array.
np.array([0., 1.])] # invalid datatype
# Some simpler indices that still cover a bit more
self.simple_indices = [Ellipsis, None, -1, [1], np.array([True]), 'skip']
# Very simple ones to fill the rest:
self.fill_indices = [slice(None, None), 0] Example 44
def broadcast_to(array, shape, subok=False):
"""Broadcast an array to a new shape.
Parameters
----------
array : array_like
The array to broadcast.
shape : tuple
The shape of the desired array.
subok : bool, optional
If True, then sub-classes will be passed-through, otherwise
the returned array will be forced to be a base-class array (default).
Returns
-------
broadcast : array
A readonly view on the original array with the given shape. It is
typically not contiguous. Furthermore, more than one element of a
broadcasted array may refer to a single memory location.
Raises
------
ValueError
If the array is not compatible with the new shape according to NumPy's
broadcasting rules.
Notes
-----
.. versionadded:: 1.10.0
Examples
--------
>>> x = np.array([1, 2, 3])
>>> np.broadcast_to(x, (3, 3))
array([[1, 2, 3],
[1, 2, 3],
[1, 2, 3]])
"""
return _broadcast_to(array, shape, subok=subok, readonly=True) Example 45
def test_broadcast_in_args(self):
# gh-5881
arrs = [np.empty((6, 7)), np.empty((5, 6, 1)), np.empty((7,)),
np.empty((5, 1, 7))]
mits = [np.broadcast(*arrs),
np.broadcast(np.broadcast(*arrs[:2]), np.broadcast(*arrs[2:])),
np.broadcast(arrs[0], np.broadcast(*arrs[1:-1]), arrs[-1])]
for mit in mits:
assert_equal(mit.shape, (5, 6, 7))
assert_equal(mit.ndim, 3)
assert_equal(mit.nd, 3)
assert_equal(mit.numiter, 4)
for a, ia in zip(arrs, mit.iters):
assert_(a is ia.base) Example 46
def test_broadcast_single_arg(self):
# gh-6899
arrs = [np.empty((5, 6, 7))]
mit = np.broadcast(*arrs)
assert_equal(mit.shape, (5, 6, 7))
assert_equal(mit.ndim, 3)
assert_equal(mit.nd, 3)
assert_equal(mit.numiter, 1)
assert_(arrs[0] is mit.iters[0].base) Example 47
def test_number_of_arguments(self):
arr = np.empty((5,))
for j in range(35):
arrs = [arr] * j
if j < 1 or j > 32:
assert_raises(ValueError, np.broadcast, *arrs)
else:
mit = np.broadcast(*arrs)
assert_equal(mit.numiter, j) Example 48
def test_boolean_assignment_value_mismatch(self):
# A boolean assignment should fail when the shape of the values
# cannot be broadcast to the subscription. (see also gh-3458)
a = np.arange(4)
def f(a, v):
a[a > -1] = v
assert_raises(ValueError, f, a, [])
assert_raises(ValueError, f, a, [1, 2, 3])
assert_raises(ValueError, f, a[:1], [1, 2, 3]) Example 49
def setUp(self):
self.a = np.arange(np.prod([3, 1, 5, 6])).reshape(3, 1, 5, 6)
self.b = np.empty((3, 0, 5, 6))
self.complex_indices = ['skip', Ellipsis,
0,
# Boolean indices, up to 3-d for some special cases of eating up
# dimensions, also need to test all False
np.array(False),
np.array([True, False, False]),
np.array([[True, False], [False, True]]),
np.array([[[False, False], [False, False]]]),
# Some slices:
slice(-5, 5, 2),
slice(1, 1, 100),
slice(4, -1, -2),
slice(None, None, -3),
# Some Fancy indexes:
np.empty((0, 1, 1), dtype=np.intp), # empty and can be broadcast
np.array([0, 1, -2]),
np.array([[2], [0], [1]]),
np.array([[0, -1], [0, 1]], dtype=np.dtype('intp').newbyteorder()),
np.array([2, -1], dtype=np.int8),
np.zeros([1]*31, dtype=int), # trigger too large array.
np.array([0., 1.])] # invalid datatype
# Some simpler indices that still cover a bit more
self.simple_indices = [Ellipsis, None, -1, [1], np.array([True]),
'skip']
# Very simple ones to fill the rest:
self.fill_indices = [slice(None, None), 0] Example 50
def broadcast_to(array, shape, subok=False):
"""Broadcast an array to a new shape.
Parameters
----------
array : array_like
The array to broadcast.
shape : tuple
The shape of the desired array.
subok : bool, optional
If True, then sub-classes will be passed-through, otherwise
the returned array will be forced to be a base-class array (default).
Returns
-------
broadcast : array
A readonly view on the original array with the given shape. It is
typically not contiguous. Furthermore, more than one element of a
broadcasted array may refer to a single memory location.
Raises
------
ValueError
If the array is not compatible with the new shape according to NumPy's
broadcasting rules.
Notes
-----
.. versionadded:: 1.10.0
Examples
--------
>>> x = np.array([1, 2, 3])
>>> np.broadcast_to(x, (3, 3))
array([[1, 2, 3],
[1, 2, 3],
[1, 2, 3]])
"""
return _broadcast_to(array, shape, subok=subok, readonly=True) 