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Paddle/python/paddle/fluid/input.py

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# Copyright (c) 2019 PaddlePaddle Authors. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from __future__ import print_function
import warnings
from .framework import Variable, in_dygraph_mode
from .layer_helper import LayerHelper
from .data_feeder import check_variable_and_dtype, check_dtype
__all__ = ['one_hot', 'embedding']
def one_hot(input, depth, allow_out_of_range=False):
"""
The operator converts each id in the input to an one-hot vector with a
depth length. The value in the vector dimension corresponding to the id
is 1, and the value in the remaining dimension is 0.
The shape of output Tensor or LoDTensor is generated by appending depth dimension
behind the last dimension of the input shape.
.. code-block:: text
Example 1 (allow_out_of_range=False):
input:
X.shape = [4]
X.data = [1, 1, 3, 0]
depth = 4
output:
Out.shape = [4, 4]
Out.data = [[0., 1., 0., 0.],
[0., 1., 0., 0.],
[0., 0., 0., 1.],
[1., 0., 0., 0.]]
Example 2 (allow_out_of_range=True):
input:
X.shape = [4]
X.data = [1, 1, 5, 0]
depth = 4
allow_out_of_range = True
output:
Out.shape = [4, 4]
Out.data = [[0., 1., 0., 0.],
[0., 1., 0., 0.],
[0., 0., 0., 0.], # This id is 5, which goes beyond depth, so set it all-zeros data.
[1., 0., 0., 0.]]
Example 3 (allow_out_of_range=False):
input:
X.shape = [4]
X.data = [1, 1, 5, 0]
depth = 4
allow_out_of_range = False
output: Throw an exception for Illegal value
The second dimension in X is 5, which is greater than depth.
Allow_out_of_range =False means that does not allow the word id to exceed depth,
so it throws an exception.
Args:
input(Variable): Tensor or LoDTensor with shape :math:`[N_1, N_2, ..., N_k]` ,
which contains at least one dimension. The data type is int32 or int64.
depth(int): An integer defining the depth of the one hot dimension. If input
is word id, depth is generally the dictionary size.
allow_out_of_range(bool): A bool value indicating whether the input
indices could be out of range :math:`[0, depth)` . When input indices are
out of range, exceptions :code:`Illegal value` is raised if :attr:`allow_out_of_range`
is False, or zero-filling representations is created if it is set True.
Default: False.
Returns:
Variable: The one-hot representations of input. A Tensor or LoDTensor with type float32.
Examples:
.. code-block:: python
import paddle.fluid as fluid
# Correspond to the first example above, where label.shape is 4 and one_hot_label.shape is [4, 4].
label = fluid.data(name="label", shape=[4], dtype="int64")
one_hot_label = fluid.one_hot(input=label, depth=4)
"""
helper = LayerHelper("one_hot_v2", **locals())
one_hot_out = helper.create_variable_for_type_inference(dtype='float32')
if in_dygraph_mode():
inputs = {'X': input}
attrs = {'depth': depth, 'allow_out_of_range': allow_out_of_range}
else:
if not isinstance(depth, Variable):
# user attribute
inputs = {'X': input}
attrs = {'depth': depth, 'allow_out_of_range': allow_out_of_range}
else:
depth.stop_gradient = True
inputs = {'X': input, 'depth_tensor': depth}
attrs = {'allow_out_of_range': allow_out_of_range}
helper.append_op(
type="one_hot_v2",
inputs=inputs,
attrs=attrs,
outputs={'Out': one_hot_out},
stop_gradient=True)
return one_hot_out
def embedding(input,
size,
is_sparse=False,
is_distributed=False,
padding_idx=None,
param_attr=None,
dtype='float32'):
"""
The operator is used to lookup embeddings vector of ids provided by :attr:`input` .
It automatically constructs a 2D embedding matrix based on the
input :attr:`size` (vocab_size, emb_size) and :attr:`dtype` .
The shape of output Tensor is generated by appending an emb_size dimension to the
last dimension of the input Tensor shape.
**Note:** The id in :attr:`input` must satisfy :math:`0 =< id < size[0]` ,
otherwise the program will throw an exception and exit.
.. code-block:: text
Case 1:
input is a Tensor. padding_idx = -1
input.data = [[1, 3], [2, 4], [4, 127]]
input.shape = [3, 2]
Given size = [128, 16]
output is a Tensor:
out.shape = [3, 2, 16]
out.data = [[[0.129435295, 0.244512452, ..., 0.436322452],
[0.345421456, 0.524563927, ..., 0.144534654]],
[[0.345249859, 0.124939536, ..., 0.194353745],
[0.945345345, 0.435394634, ..., 0.435345365]],
[[0.945345345, 0.435394634, ..., 0.435345365],
[0.0, 0.0, ..., 0.0 ]]] # padding data
The input padding_idx is less than 0, it is automatically converted to padding_idx = -1 + 128 = 127
It will pad all-zero data when ids is 127.
Case 2:
input is a LoDTensor with 1-level LoD. padding_idx = 0
input.lod = [[2, 3]]
input.data = [[1], [3], [2], [4], [0]]
input.shape = [5, 1]
Given size = [128, 16]
output is a LoDTensor:
out.lod = [[2, 3]]
out.shape = [5, 1, 16]
out.data = [[[0.129435295, 0.244512452, ..., 0.436322452]],
[[0.345421456, 0.524563927, ..., 0.144534654]],
[[0.345249859, 0.124939536, ..., 0.194353745]],
[[0.945345345, 0.435394634, ..., 0.435345365]],
[[0.0, 0.0, ..., 0.0 ]]] # padding data
It will pad all-zero data when ids is 0.
Args:
input(Variable): A Tensor or LoDTensor with type int64, which contains the id information.
The value of the input id should satisfy :math:`0<= id < size[0]` .
size(tuple|list): The shape of lookup table parameter. It should have two elements which
indicates the size of the dictionary of embeddings and the size of each embedding vector respectively.
is_sparse(bool): The flag indicating whether to use sparse update. This parameter only
affects the performance of the backwards gradient update. It is recommended to set
True because sparse update is faster. But some optimizer does not support sparse update,
such as :ref:`api_fluid_optimizer_AdadeltaOptimizer` , :ref:`api_fluid_optimizer_AdamaxOptimizer` ,
:ref:`api_fluid_optimizer_DecayedAdagradOptimizer` , :ref:`api_fluid_optimizer_FtrlOptimizer` ,
:ref:`api_fluid_optimizer_LambOptimizer` and :ref:`api_fluid_optimizer_LarsMomentumOptimizer` .
In these case, is_sparse must be False. Default: False.
is_distributed(bool): Whether to store the embedding matrix in a distributed manner. Only used
in multi-machine distributed CPU training. Default: False.
padding_idx(int|long|None): padding_idx needs to be in the interval [-vocab_size, vocab_size).
If :math:`padding\_idx < 0`, the :math:`padding\_idx` will automatically be converted
to :math:`vocab\_size + padding\_idx` . It will output all-zero padding data whenever lookup
encounters :math:`padding\_idx` in id. And the padding data will not be updated while training.
If set None, it makes no effect to output. Default: None.
param_attr(ParamAttr): To specify the weight parameter property. Default: None, which means the
default weight parameter property is used. See usage for details in :ref:`api_fluid_ParamAttr` . In addition,
user-defined or pre-trained word vectors can be loaded with the :attr:`param_attr` parameter.
The local word vector needs to be transformed into numpy format, and the shape of local word
vector should be consistent with :attr:`size` . Then :ref:`api_fluid_initializer_NumpyArrayInitializer`
is used to load custom or pre-trained word vectors. See code example 2 for details.
dtype(str|core.VarDesc.VarType): It refers to the data type of output Tensor.
It must be float32 or float64. Default: float32.
Returns:
Variable: Embedding Tensor or LoDTensor mapped by input. The data type is the same as :attr:`dtype` .
Examples:
.. code-block:: python
import paddle.fluid as fluid
import numpy as np
data = fluid.data(name='x', shape=[None, 10], dtype='int64')
# example 1
emb_1 = fluid.embedding(input=data, size=[128, 64])
# example 2: load custom or pre-trained word vectors
weight_data = np.random.random(size=(128, 100)) # word vectors with numpy format
w_param_attrs = fluid.ParamAttr(
name="emb_weight",
learning_rate=0.5,
initializer=fluid.initializer.NumpyArrayInitializer(weight_data),
trainable=True)
emb_2 = fluid.embedding(input=data, size=(128, 100), param_attr=w_param_attrs, dtype='float32')
"""
helper = LayerHelper('embedding', **locals())
check_variable_and_dtype(input, 'input', ['int64'], 'fluid.embedding')
check_dtype(dtype, 'dtype', ['float16', 'float32', 'float64'],
'fluid.embedding')
remote_prefetch = is_sparse and (not is_distributed)
if remote_prefetch:
assert is_sparse is True and is_distributed is False
w = helper.create_parameter(
attr=helper.param_attr, shape=size, dtype=dtype, is_bias=False)
tmp = helper.create_variable_for_type_inference(dtype)
padding_idx = -1 if padding_idx is None else padding_idx if padding_idx >= 0 else (
size[0] + padding_idx)
helper.append_op(
type='lookup_table_v2',
inputs={'Ids': input,
'W': w},
outputs={'Out': tmp},
attrs={
'is_sparse': is_sparse,
'is_distributed': is_distributed,
'remote_prefetch': remote_prefetch,
'padding_idx': padding_idx
})
return tmp