目录
Tensor
Represents one of the outputs of an Operation
.
Aliases:
A Tensor
is a symbolic handle to one of the outputs of an Operation
. It does not hold the values of that operation's output, but instead provides a means of computing those values in a TensorFlow tf.compat.v1.Session.
This class has two primary purposes:
Tensor
can be passed as an input to another Operation
. This builds a dataflow connection between operations, which enables TensorFlow to execute an entire Graph
that represents a large, multi-step computation.
Tensor
can be computed by passing it to tf.Session.run
. t.eval()
is a shortcut for calling tf.compat.v1.get_default_session().run(t)
.
In the following example, c
, d
, and e
are symbolic Tensor
objects, whereas result
is a numpy array that stores a concrete value:
# Build a dataflow graph.
c = tf.constant([[1.0, 2.0], [3.0, 4.0]])
d = tf.constant([[1.0, 1.0], [0.0, 1.0]])
e = tf.matmul(c, d)
# Construct a `Session` to execute the graph.
sess = tf.compat.v1.Session()
# Execute the graph and store the value that `e` represents in `result`.
result = sess.run(e)
__init__
__init__(
op,
value_index,
dtype
)
Creates a new Tensor
.
Args:
op
: An Operation
. Operation
that computes this tensor.value_index
: An int
. Index of the operation's endpoint that produces this tensor.dtype
: A DType
. Type of elements stored in this tensor.Raises:
TypeError
: If the op is not an Operation
.device
The name of the device on which this tensor will be produced, or None.
dtype
The DType
of elements in this tensor.
graph
The Graph
that contains this tensor.
name
The string name of this tensor.
op
The Operation
that produces this tensor as an output.
shape
Returns the TensorShape
that represents the shape of this tensor.
The shape is computed using shape inference functions that are registered in the Op for each Operation
. See tf.TensorShape for more details of what a shape represents.
The inferred shape of a tensor is used to provide shape information without having to launch the graph in a session. This can be used for debugging, and providing early error messages. For example:
c = tf.constant([[1.0, 2.0, 3.0], [4.0, 5.0, 6.0]])
print(c.shape)
==> TensorShape([Dimension(2), Dimension(3)])
d = tf.constant([[1.0, 0.0], [0.0, 1.0], [1.0, 0.0], [0.0, 1.0]])
print(d.shape)
==> TensorShape([Dimension(4), Dimension(2)])
# Raises a ValueError, because `c` and `d` do not have compatible
# inner dimensions.
e = tf.matmul(c, d)
f = tf.matmul(c, d, transpose_a=True, transpose_b=True)
print(f.shape)
==> TensorShape([Dimension(3), Dimension(4)])
In some cases, the inferred shape may have unknown dimensions. If the caller has additional information about the values of these dimensions, Tensor.set_shape() can be used to augment the inferred shape.
Returns:
A TensorShape
representing the shape of this tensor.
value_index
The index of this tensor in the outputs of its Operation
.
1、__abs__
__abs__(
x,
name=None
)
Computes the absolute value of a tensor.Given a tensor of integer or floating-point values, this operation returns a tensor of the same type, where each element contains the absolute value of the corresponding element in the input.Given a tensor x
of complex numbers, this operation returns a tensor of type float32
or float64
that is the absolute value of each element in x
. All elements in x
must be complex numbers of the form. The absolute value is computed as. For example:
x = tf.constant([[-2.25 + 4.75j], [-3.25 + 5.75j]])
tf.abs(x) # [5.25594902, 6.60492229]
Args:
x
: A Tensor
or SparseTensor
of type float16
, float32
, float64
, int32
, int64
, complex64
or complex128
.name
: A name for the operation (optional).Returns:
Tensor
or SparseTensor
the same size, type, and sparsity as x
with absolute values. Note, for complex64
or complex128
input, the returned Tensor
will be of type float32
or float64
, respectively.If x
is a SparseTensor
, returns SparseTensor(x.indices, tf.math.abs(x.values, ...), x.dense_shape)
2、__add__
__add__(
x,
y
)
Dispatches to add for strings and add_v2 for all other types.
3、__and__
__and__(
x,
y
)
Returns the truth value of x AND y element-wise.
NOTE: math.logical_and supports broadcasting. More about broadcasting here
Args:
x
: A Tensor
of type bool
.y
: A Tensor
of type bool
.name
: A name for the operation (optional).Returns:
Tensor
of type bool
.4、__bool__
__bool__()
Dummy method to prevent a tensor from being used as a Python bool
.
This overload raises a TypeError
when the user inadvertently treats a Tensor
as a boolean (most commonly in an if
or while
statement), in code that was not converted by AutoGraph. For example:
if tf.constant(True): # Will raise.
# ...
if tf.constant(5) < tf.constant(7): # Will raise.
# ...
Raises:
TypeError
.5、__div__
__div__(
x,
y
)
Divide two values using Python 2 semantics.
Used for Tensor.div.
Args:
x
: Tensor
numerator of real numeric type.y
: Tensor
denominator of real numeric type.name
: A name for the operation (optional).Returns:
x / y
returns the quotient of x and y.6、__eq__
__eq__(other)
Compares two tensors element-wise for equality.
7、__floordiv__
__floordiv__(
x,
y
)
Divides x / y
elementwise, rounding toward the most negative integer.
The same as tf.compat.v1.div(x,y) for integers, but uses tf.floor(tf.compat.v1.div(x,y))
for floating point arguments so that the result is always an integer (though possibly an integer represented as floating point). This op is generated by x // y
floor division in Python 3 and in Python 2.7 with from __future__ import division
.
x
and y
must have the same type, and the result will have the same type as well.
Args:
x
: Tensor
numerator of real numeric type.y
: Tensor
denominator of real numeric type.name
: A name for the operation (optional).Returns:
x / y
rounded down.Raises:
TypeError
: If the inputs are complex.8、__ge__
Defined in generated file: python/ops/gen_math_ops.py
__ge__(
x,
y,
name=None
)
Returns the truth value of (x >= y) element-wise.
NOTE: math.greater_equal supports broadcasting. More about broadcasting here
Args:
x
: A Tensor
. Must be one of the following types: float32
, float64
, int32
, uint8
, int16
, int8
, int64
, bfloat16
, uint16
, half
, uint32
, uint64
.y
: A Tensor
. Must have the same type as x
.name
: A name for the operation (optional).Returns:
Tensor
of type bool
.9、__getitem__
__getitem__(
tensor,
slice_spec,
var=None
)
Overload for Tensor.getitem.
This operation extracts the specified region from the tensor. The notation is similar to NumPy with the restriction that currently only support basic indexing. That means that using a non-scalar tensor as input is not currently allowed.
Some useful examples:
# Strip leading and trailing 2 elements
foo = tf.constant([1,2,3,4,5,6])
print(foo[2:-2].eval()) # => [3,4]
# Skip every other row and reverse the order of the columns
foo = tf.constant([[1,2,3], [4,5,6], [7,8,9]])
print(foo[::2,::-1].eval()) # => [[3,2,1], [9,8,7]]
# Use scalar tensors as indices on both dimensions
print(foo[tf.constant(0), tf.constant(2)].eval()) # => 3
# Insert another dimension
foo = tf.constant([[1,2,3], [4,5,6], [7,8,9]])
print(foo[tf.newaxis, :, :].eval()) # => [[[1,2,3], [4,5,6], [7,8,9]]]
print(foo[:, tf.newaxis, :].eval()) # => [[[1,2,3]], [[4,5,6]], [[7,8,9]]]
print(foo[:, :, tf.newaxis].eval()) # => [[[1],[2],[3]], [[4],[5],[6]],
[[7],[8],[9]]]
# Ellipses (3 equivalent operations)
foo = tf.constant([[1,2,3], [4,5,6], [7,8,9]])
print(foo[tf.newaxis, :, :].eval()) # => [[[1,2,3], [4,5,6], [7,8,9]]]
print(foo[tf.newaxis, ...].eval()) # => [[[1,2,3], [4,5,6], [7,8,9]]]
print(foo[tf.newaxis].eval()) # => [[[1,2,3], [4,5,6], [7,8,9]]]
# Masks
foo = tf.constant([[1,2,3], [4,5,6], [7,8,9]])
print(foo[foo > 2].eval()) # => [3, 4, 5, 6, 7, 8, 9]
Notes:
tf.newaxis
is None
as in NumPy.slice_spec
Args:
tensor
: An ops.Tensor object.slice_spec
: The arguments to Tensor.getitem.var
: In the case of variable slice assignment, the Variable object to slice (i.e. tensor is the read-only view of this variable).Returns:
Raises:
ValueError
: If a slice range is negative size.TypeError
: If the slice indices aren't int, slice, ellipsis, tf.newaxis or scalar int32/int64 tensors.10、__gt__
Defined in generated file: python/ops/gen_math_ops.py
__gt__(
x,
y,
name=None
)
Returns the truth value of (x > y) element-wise.
NOTE: math.greater supports broadcasting. More about broadcasting here
Args:
x
: A Tensor
. Must be one of the following types: float32
, float64
, int32
, uint8
, int16
, int8
, int64
, bfloat16
, uint16
, half
, uint32
, uint64
.y
: A Tensor
. Must have the same type as x
.name
: A name for the operation (optional).Returns:
Tensor
of type bool
.10、__invert__
Defined in generated file: python/ops/gen_math_ops.py
__invert__(
x,
name=None
)
Returns the truth value of NOT x element-wise.
Args:
x
: A Tensor
of type bool
.name
: A name for the operation (optional).Returns:
Tensor
of type bool
.11、__iter__
__iter__()
12、__le__
Defined in generated file: python/ops/gen_math_ops.py
__le__(
x,
y,
name=None
)
Returns the truth value of (x <= y) element-wise.
NOTE: math.less_equal supports broadcasting. More about broadcasting here
Args:
x
: A Tensor
. Must be one of the following types: float32
, float64
, int32
, uint8
, int16
, int8
, int64
, bfloat16
, uint16
, half
, uint32
, uint64
.y
: A Tensor
. Must have the same type as x
.name
: A name for the operation (optional).Returns:
Tensor
of type bool
.13、__len__
__len__()
14、__lt__
Defined in generated file: python/ops/gen_math_ops.py
__lt__(
x,
y,
name=None
)
Returns the truth value of (x < y) element-wise.
NOTE: math.less supports broadcasting. More about broadcasting here
Args:
x
: A Tensor
. Must be one of the following types: float32
, float64
, int32
, uint8
, int16
, int8
, int64
, bfloat16
, uint16
, half
, uint32
, uint64
.y
: A Tensor
. Must have the same type as x
.name
: A name for the operation (optional).Returns:
Tensor
of type bool
.15、__matmul__
__matmul__(
x,
y
)
Multiplies matrix a
by matrix b
, producing a
* b
.
The inputs must, following any transpositions, be tensors of rank >= 2 where the inner 2 dimensions specify valid matrix multiplication arguments, and any further outer dimensions match.
Both matrices must be of the same type. The supported types are: float16
, float32
, float64
, int32
, complex64
, complex128
.
Either matrix can be transposed or adjointed (conjugated and transposed) on the fly by setting one of the corresponding flag to True
. These are False
by default.
If one or both of the matrices contain a lot of zeros, a more efficient multiplication algorithm can be used by setting the corresponding a_is_sparse
or b_is_sparse
flag to True
. These are False
by default. This optimization is only available for plain matrices (rank-2 tensors) with datatypes bfloat16
or float32
.
For example:
# 2-D tensor `a`
# [[1, 2, 3],
# [4, 5, 6]]
a = tf.constant([1, 2, 3, 4, 5, 6], shape=[2, 3])
# 2-D tensor `b`
# [[ 7, 8],
# [ 9, 10],
# [11, 12]]
b = tf.constant([7, 8, 9, 10, 11, 12], shape=[3, 2])
# `a` * `b`
# [[ 58, 64],
# [139, 154]]
c = tf.matmul(a, b)
# 3-D tensor `a`
# [[[ 1, 2, 3],
# [ 4, 5, 6]],
# [[ 7, 8, 9],
# [10, 11, 12]]]
a = tf.constant(np.arange(1, 13, dtype=np.int32),
shape=[2, 2, 3])
# 3-D tensor `b`
# [[[13, 14],
# [15, 16],
# [17, 18]],
# [[19, 20],
# [21, 22],
# [23, 24]]]
b = tf.constant(np.arange(13, 25, dtype=np.int32),
shape=[2, 3, 2])
# `a` * `b`
# [[[ 94, 100],
# [229, 244]],
# [[508, 532],
# [697, 730]]]
c = tf.matmul(a, b)
# Since python >= 3.5 the @ operator is supported (see PEP 465).
# In TensorFlow, it simply calls the `tf.matmul()` function, so the
# following lines are equivalent:
d = a @ b @ [[10.], [11.]]
d = tf.matmul(tf.matmul(a, b), [[10.], [11.]])
Args:
a
: Tensor
of type float16
, float32
, float64
, int32
, complex64
, complex128
and rank > 1.b
: Tensor
with same type and rank as a
.transpose_a
: If True
, a
is transposed before multiplication.transpose_b
: If True
, b
is transposed before multiplication.adjoint_a
: If True
, a
is conjugated and transposed before multiplication.adjoint_b
: If True
, b
is conjugated and transposed before multiplication.a_is_sparse
: If True
, a
is treated as a sparse matrix.b_is_sparse
: If True
, b
is treated as a sparse matrix.name
: Name for the operation (optional).Returns:
Tensor
of the same type as a
and b
where each inner-most matrix is the product of the corresponding matrices in a
and b
, e.g. if all transpose or adjoint attributes are False
:output
[..., i, j] = sum_k (a
[..., i, k] * b
[..., k, j]), for all indices i, j.Note
: This is matrix product, not element-wise product.Raises:
ValueError
: If transpose_a and adjoint_a, or transpose_b and adjoint_b are both set to True.16、__mod__
__mod__(
x,
y
)
Returns element-wise remainder of division. When x < 0
xor y < 0
is
true, this follows Python semantics in that the result here is consistent with a flooring divide. E.g. floor(x / y) * y + mod(x, y) = x
.
NOTE: math.floormod supports broadcasting. More about broadcasting here
Args:
x
: A Tensor
. Must be one of the following types: int32
, int64
, bfloat16
, half
, float32
, float64
.y
: A Tensor
. Must have the same type as x
.name
: A name for the operation (optional).Returns:
Tensor
. Has the same type as x
.17、__mul__
__mul__(
x,
y
)
Dispatches cwise mul for "DenseDense" and "DenseSparse".
18、__ne__
__ne__(other)
Compares two tensors element-wise for equality.
19、__neg__
Defined in generated file: python/ops/gen_math_ops.py
__neg__(
x,
name=None
)
Computes numerical negative value element-wise.
I.e.,
Args:
x
: A Tensor
. Must be one of the following types: bfloat16
, half
, float32
, float64
, int32
, int64
, complex64
, complex128
.name
: A name for the operation (optional).Returns:
Tensor
. Has the same type as x
.If x
is a SparseTensor
, returns SparseTensor(x.indices, tf.math.negative(x.values, ...), x.dense_shape)
20、__nonzero__
__nonzero__()
Dummy method to prevent a tensor from being used as a Python bool
.
This is the Python 2.x counterpart to __bool__()
above.
Raises:
TypeError
.21、__or__
__or__(
x,
y
)
Returns the truth value of x OR y element-wise.
NOTE: math.logical_or supports broadcasting. More about broadcasting here
Args:
x
: A Tensor
of type bool
.y
: A Tensor
of type bool
.name
: A name for the operation (optional).Returns:
Tensor
of type bool
.22、__pow__
__pow__(
x,
y
)
Computes the power of one value to another.
Given a tensor x
and a tensor y
, this operation computes
for corresponding elements in x
and y
. For example:
x = tf.constant([[2, 2], [3, 3]])
y = tf.constant([[8, 16], [2, 3]])
tf.pow(x, y) # [[256, 65536], [9, 27]]
Args:
x
: A Tensor
of type float16
, float32
, float64
, int32
, int64
, complex64
, or complex128
.y
: A Tensor
of type float16
, float32
, float64
, int32
, int64
, complex64
, or complex128
.name
: A name for the operation (optional).Returns:
Tensor
.23、__radd__
__radd__(
y,
x
)
Dispatches to add for strings and add_v2 for all other types.
24、__rand__
__rand__(
y,
x
)
Returns the truth value of x AND y element-wise.
NOTE: math.logical_and supports broadcasting. More about broadcasting here
Args:
x
: A Tensor
of type bool
.y
: A Tensor
of type bool
.name
: A name for the operation (optional).Returns:
Tensor
of type bool
.25、__rdiv__
__rdiv__(
y,
x
)
Divide two values using Python 2 semantics.
Used for Tensor.div.
Args:
x
: Tensor
numerator of real numeric type.y
: Tensor
denominator of real numeric type.name
: A name for the operation (optional).Returns:
x / y
returns the quotient of x and y.26、__rfloordiv__
__rfloordiv__(
y,
x
)
Divides x / y
elementwise, rounding toward the most negative integer.
The same as tf.compat.v1.div(x,y) for integers, but uses tf.floor(tf.compat.v1.div(x,y))
for floating point arguments so that the result is always an integer (though possibly an integer represented as floating point). This op is generated by x // y
floor division in Python 3 and in Python 2.7 with from __future__ import division
.
x
and y
must have the same type, and the result will have the same type as well.
Args:
x
: Tensor
numerator of real numeric type.y
: Tensor
denominator of real numeric type.name
: A name for the operation (optional).Returns:
x / y
rounded down.Raises:
TypeError
: If the inputs are complex.27、__rmatmul__
__rmatmul__(
y,
x
)
Multiplies matrix a
by matrix b
, producing a
* b
.
The inputs must, following any transpositions, be tensors of rank >= 2 where the inner 2 dimensions specify valid matrix multiplication arguments, and any further outer dimensions match.
Both matrices must be of the same type. The supported types are: float16
, float32
, float64
, int32
, complex64
, complex128
.
Either matrix can be transposed or adjointed (conjugated and transposed) on the fly by setting one of the corresponding flag to True
. These are False
by default.
If one or both of the matrices contain a lot of zeros, a more efficient multiplication algorithm can be used by setting the corresponding a_is_sparse
or b_is_sparse
flag to True
. These are False
by default. This optimization is only available for plain matrices (rank-2 tensors) with datatypes bfloat16
or float32
.
For example:
Args:
a
: Tensor
of type float16
, float32
, float64
, int32
, complex64
, complex128
and rank > 1.b
: Tensor
with same type and rank as a
.transpose_a
: If True
, a
is transposed before multiplication.transpose_b
: If True
, b
is transposed before multiplication.adjoint_a
: If True
, a
is conjugated and transposed before multiplication.adjoint_b
: If True
, b
is conjugated and transposed before multiplication.a_is_sparse
: If True
, a
is treated as a sparse matrix.b_is_sparse
: If True
, b
is treated as a sparse matrix.name
: Name for the operation (optional).Returns:
Tensor
of the same type as a
and b
where each inner-most matrix is the product of the corresponding matrices in a
and b
, e.g. if all transpose or adjoint attributes are False
:output
[..., i, j] = sum_k (a
[..., i, k] * b
[..., k, j]), for all indices i, j.Note
: This is matrix product, not element-wise product.Raises:
ValueError
: If transpose_a and adjoint_a, or transpose_b and adjoint_b are both set to True.28、__rmod__
__rmod__(
y,
x
)
Returns element-wise remainder of division. When x < 0
xor y < 0
is
true, this follows Python semantics in that the result here is consistent with a flooring divide. E.g. floor(x / y) * y + mod(x, y) = x
.
NOTE: math.floormod supports broadcasting. More about broadcasting here
Args:
x
: A Tensor
. Must be one of the following types: int32
, int64
, bfloat16
, half
, float32
, float64
.y
: A Tensor
. Must have the same type as x
.name
: A name for the operation (optional).Returns:
Tensor
. Has the same type as x
.29、__rmul__
__rmul__(
y,
x
)
Dispatches cwise mul for "DenseDense" and "DenseSparse".
30、__ror__
__ror__(
y,
x
)
Returns the truth value of x OR y element-wise.
NOTE: math.logical_or supports broadcasting. More about broadcasting here
Args:
x
: A Tensor
of type bool
.y
: A Tensor
of type bool
.name
: A name for the operation (optional).Returns:
Tensor
of type bool
.31、__rpow__
__rpow__(
y,
x
)
Computes the power of one value to another.
Given a tensor x
and a tensor y
, this operation computes
for corresponding elements in x
and y
. For example:
x = tf.constant([[2, 2], [3, 3]])
y = tf.constant([[8, 16], [2, 3]])
tf.pow(x, y) # [[256, 65536], [9, 27]]
Args:
x
: A Tensor
of type float16
, float32
, float64
, int32
, int64
, complex64
, or complex128
.y
: A Tensor
of type float16
, float32
, float64
, int32
, int64
, complex64
, or complex128
.name
: A name for the operation (optional).Returns:
Tensor
.32、__rsub__
__rsub__(
y,
x
)
Returns x - y element-wise.
NOTE: Subtract
supports broadcasting. More about broadcasting here
Args:
x
: A Tensor
. Must be one of the following types: bfloat16
, half
, float32
, float64
, uint8
, int8
, uint16
, int16
, int32
, int64
, complex64
, complex128
.y
: A Tensor
. Must have the same type as x
.name
: A name for the operation (optional).Returns:
Tensor
. Has the same type as x
.33、__rtruediv__
__rtruediv__(
y,
x
)
34、__rxor__
__rxor__(
y,
x
)
Logical XOR function.
x ^ y = (x | y) & ~(x & y)
Inputs are tensor and if the tensors contains more than one element, an element-wise logical XOR is computed.
Usage:
x = tf.constant([False, False, True, True], dtype = tf.bool)
y = tf.constant([False, True, False, True], dtype = tf.bool)
z = tf.logical_xor(x, y, name="LogicalXor")
# here z = [False True True False]
Args:
x
: A Tensor
type bool.y
: A Tensor
of type bool.Returns:
Tensor
of type bool with the same size as that of x or y.35、__sub__
__sub__(
x,
y
)
Returns x - y element-wise.
NOTE: Subtract
supports broadcasting. More about broadcasting here
Args:
x
: A Tensor
. Must be one of the following types: bfloat16
, half
, float32
, float64
, uint8
, int8
, uint16
, int16
, int32
, int64
, complex64
, complex128
.y
: A Tensor
. Must have the same type as x
.name
: A name for the operation (optional).Returns:
Tensor
. Has the same type as x
.36、__truediv__
__truediv__(
x,
y
)
37、__xor__
__xor__(
x,
y
)
Logical XOR function.
x ^ y = (x | y) & ~(x & y)
Inputs are tensor and if the tensors contains more than one element, an element-wise logical XOR is computed.
Usage:
x = tf.constant([False, False, True, True], dtype = tf.bool)
y = tf.constant([False, True, False, True], dtype = tf.bool)
z = tf.logical_xor(x, y, name="LogicalXor")
# here z = [False True True False]
Args:
x
: A Tensor
type bool.y
: A Tensor
of type bool.Returns:
Tensor
of type bool with the same size as that of x or y.38、consumers
consumers()
Returns a list of Operation
s that consume this tensor.
Returns:
A list of Operation
s.
39、eval
eval(
feed_dict=None,
session=None
)
Evaluates this tensor in a Session
.Calling this method will execute all preceding operations that produce the inputs needed for the operation that produces this tensor.
N.B. Before invoking Tensor.eval(), its graph must have been launched in a session, and either a default session must be available, or session
must be specified explicitly.
Args:
feed_dict
: A dictionary that maps Tensor
objects to feed values. See tf.Session.run
for a description of the valid feed values.session
: (Optional.) The Session
to be used to evaluate this tensor. If none, the default session will be used.Returns:
例:
import tensorflow as tf
a=tf.constant([1.0,2.0],name="a")
b=tf.constant([2.0,3.0],name="b")
c=tf.add(a,b,name="sum")
print(c)
sess=tf.Session()
with sess.as_default():
print(c.eval())
Output:
--------------------------------------------
Tensor(“sum:0”, shape=(2,), dtype=float32)
[ 3. 5.]
--------------------------------------------
40、experimental_ref
experimental_ref()
Returns a hashable reference object to this Tensor.
Warning: Experimental API that could be changed or removed.
The primary usecase for this API is to put tensors in a set/dictionary. We can't put tensors in a set/dictionary as tensor.__hash__()
is no longer available starting Tensorflow 2.0.
import tensorflow as tf
x = tf.constant(5)
y = tf.constant(10)
z = tf.constant(10)
# The followings will raise an exception starting 2.0
# TypeError: Tensor is unhashable if Tensor equality is enabled.
tensor_set = {x, y, z}
tensor_dict = {x: 'five', y: 'ten', z: 'ten'}
Instead, we can use tensor.experimental_ref()
.
tensor_set = {x.experimental_ref(),
y.experimental_ref(),
z.experimental_ref()}
print(x.experimental_ref() in tensor_set)
==> True
tensor_dict = {x.experimental_ref(): 'five',
y.experimental_ref(): 'ten',
z.experimental_ref(): 'ten'}
print(tensor_dict[y.experimental_ref()])
==> ten
Also, the reference object provides .deref()
function that returns the original Tensor.
x = tf.constant(5)
print(x.experimental_ref().deref())
==> tf.Tensor(5, shape=(), dtype=int32)
41、get_shape
get_shape()
Alias of Tensor.shape.
42、set_shape
set_shape(shape)
Updates the shape of this tensor.
This method can be called multiple times, and will merge the given shape
with the current shape of this tensor. It can be used to provide additional information about the shape of this tensor that cannot be inferred from the graph alone. For example, this can be used to provide additional information about the shapes of images:
_, image_data = tf.compat.v1.TFRecordReader(...).read(...)
image = tf.image.decode_png(image_data, channels=3)
# The height and width dimensions of `image` are data dependent, and
# cannot be computed without executing the op.
print(image.shape)
==> TensorShape([Dimension(None), Dimension(None), Dimension(3)])
# We know that each image in this dataset is 28 x 28 pixels.
image.set_shape([28, 28, 3])
print(image.shape)
==> TensorShape([Dimension(28), Dimension(28), Dimension(3)])
NOTE: This shape is not enforced at runtime. Setting incorrect shapes can result in inconsistencies between the statically-known graph and the runtime value of tensors. For runtime validation of the shape, use tf.ensure_shape instead.
Args:
shape
: A TensorShape
representing the shape of this tensor, a TensorShapeProto
, a list, a tuple, or None.Raises:
ValueError
: If shape
is not compatible with the current shape of this tensor.