# Copyright (c) 2020 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. # TODO: define the common classes to build a neural network from ...fluid.dygraph import BilinearTensorProduct #DEFINE_ALIAS from ...fluid.dygraph import Pool2D #DEFINE_ALIAS from ...fluid.dygraph import Linear #DEFINE_ALIAS from ...fluid.dygraph import Flatten #DEFINE_ALIAS from ...fluid.dygraph import layers from .. import functional as F from ...fluid.framework import _dygraph_tracer __all__ = [ 'BilinearTensorProduct', 'Pool2D', 'Embedding', 'Linear', 'UpSample', 'Pad2D', 'UpsamplingNearest2d', 'UpsamplingBilinear2d', 'ReflectionPad1d', 'ReplicationPad1d', 'ConstantPad1d', 'ReflectionPad2d', 'ReplicationPad2d', 'ConstantPad2d', 'ZeroPad2d', 'ConstantPad3d', 'ReplicationPad3d', 'CosineSimilarity', 'Dropout', 'Dropout2d', 'Dropout3d', 'Bilinear', 'AlphaDropout', ] class Linear(layers.Layer): """ Fully-connected linear transformation layer: .. math:: Out = {XW + b} where :math:`X` is the input Tensor, :math:`W` and :math:`b` are weight and bias respectively. Linear layer takes only one ``Tensor`` input. The Linear layer multiplies input tensor with weight matrix and produces an output Tensor of shape [N, *, `output_dim`], where N is batch size and `*` means any number of additional dimensions. If ``bias_attr`` is not None, a bias variable will be created and added to the output. Parameters: in_features(int): The number of input units in this layer. out_features(int): The number of output units in this layer. weight_attr(ParamAttr or list of ParamAttr, optional): The parameter attribute for learnable weights(Parameter) of this layer. Default: None. bias_attr(ParamAttr or list of ParamAttr, optional): The attribute for the bias of this layer. If it is set to False, no bias will be added to the output units. If it is set to None, the bias is initialized zero. Default: None. name(str|None): For detailed information, please refer to :ref:`api_guide_Name`. Default: None. Attributes: **weight** (Parameter): the learnable weights of this layer. **bias** (Parameter or None): the learnable bias of this layer. Returns: None Examples: .. code-block:: python import paddle from paddle import nn import numpy as np data = np.ones((3,1,2), np.float32) place = paddle.CPUPlace() paddle.disable_static(place) data = paddle.to_tensor(data) weight_attr=paddle.framework.ParamAttr(name="linear_weight", learning_rate=1.0, trainable=False, regularizer=None, initializer=paddle.fluid.initializer.ConstantInitializer(value=1.0)) bias_attr=paddle.framework.ParamAttr(name="linear_bias", learning_rate=1.0, trainable=False, regularizer=None, initializer=paddle.fluid.initializer.ConstantInitializer(value=1.0)) linear = nn.Linear(2,2,weight_attr=weight_attr, bias_attr=bias_attr) res = linear(data) # [3 3 3 3 3 3] """ def __init__(self, in_features, out_features, weight_attr=None, bias_attr=None, name=None): super(Linear, self).__init__() self._dtype = self._helper.get_default_dtype() self._weight_attr = weight_attr self._bias_attr = bias_attr self.name = name self.weight = self.create_parameter( shape=[in_features, out_features], attr=self._weight_attr, dtype=self._dtype, is_bias=False) self.bias = self.create_parameter( shape=[out_features], attr=self._bias_attr, dtype=self._dtype, is_bias=True) self.name = name def forward(self, input): out = F.linear( x=input, weight=self.weight, bias=self.bias, name=self.name) return out class UpSample(layers.Layer): """ This op resizes a batch of images. The input must be a 3-D Tensor of the shape (num_batches, channels, in_w) or 4-D (num_batches, channels, in_h, in_w), or a 5-D Tensor of the shape (num_batches, channels, in_d, in_h, in_w) or (num_batches, in_d, in_h, in_w, channels), and the resizing only applies on the three dimensions(depth, height and width). Supporting resample methods: 'linear' : Linear interpolation 'bilinear' : Bilinear interpolation 'trilinear' : Trilinear interpolation 'nearest' : Nearest neighbor interpolation 'bicubic' : Bicubic interpolation Linear interpolation is the method of using a line connecting two known quantities to determine the value of an unknown quantity between the two known quantities. Nearest neighbor interpolation is to perform nearest neighbor interpolation in both the 3rd dimension(in height direction) and the 4th dimension(in width direction) on input tensor. Bilinear interpolation is an extension of linear interpolation for interpolating functions of two variables (e.g. H-direction and W-direction in this op) on a rectilinear 2D grid. The key idea is to perform linear interpolation first in one direction, and then again in the other direction. Bicubic interpolation is an extension of cubic interpolation for interpolating data points on a two-dimensional regular grid. The interpolated surface is smoother than corresponding surfaces obtained by bilinear interpolation or nearest-neighbor interpolation. Trilinear interpolation is an extension of linear interpolation for interpolating functions of three variables (e.g. D-direction, H-direction and W-direction in this op) on a rectilinear 3D grid. The linear interpolation is performed on three directions. align_corners and align_mode are optional parameters,the calculation method of interpolation can be selected by them. Example: .. code-block:: text For scale_factor: if align_corners = True && out_size > 1 : scale_factor = (in_size-1.0)/(out_size-1.0) else: scale_factor = float(in_size/out_size) Linear interpolation: if: align_corners = False , align_mode = 0 input : (N,C,W_in) output: (N,C,W_out) where: W_out = (W_{in}+0.5) * scale_{factor} - 0.5 else: input : (N,C,W_in) output: (N,C,W_out) where: W_out = W_{in} * scale_{factor} Nearest neighbor interpolation: if: align_corners = False input : (N,C,H_in,W_in) output: (N,C,H_out,W_out) where: H_out = floor (H_{in} * scale_{factor}) W_out = floor (W_{in} * scale_{factor}) else: align_corners = True input : (N,C,H_in,W_in) output: (N,C,H_out,W_out) where: H_out = round(H_{in} * scale_{factor}) W_out = round(W_{in} * scale_{factor}) Bilinear interpolation: if: align_corners = False , align_mode = 0 input : (N,C,H_in,W_in) output: (N,C,H_out,W_out) where: H_out = (H_{in}+0.5) * scale_{factor} - 0.5 W_out = (W_{in}+0.5) * scale_{factor} - 0.5 else: input : (N,C,H_in,W_in) output: (N,C,H_out,W_out) where: H_out = H_{in} * scale_{factor} W_out = W_{in} * scale_{factor} Bicubic interpolation: if: align_corners = False input : (N,C,H_in,W_in) output: (N,C,H_out,W_out) where: H_out = (H_{in}+0.5) * scale_{factor} - 0.5 W_out = (W_{in}+0.5) * scale_{factor} - 0.5 else: input : (N,C,H_in,W_in) output: (N,C,H_out,W_out) where: H_out = H_{in} * scale_{factor} W_out = W_{in} * scale_{factor} Trilinear interpolation: if: align_corners = False , align_mode = 0 input : (N,C,D_in,H_in,W_in) output: (N,C,D_out,H_out,W_out) where: D_out = (D_{in}+0.5) * scale_{factor} - 0.5 H_out = (H_{in}+0.5) * scale_{factor} - 0.5 W_out = (W_{in}+0.5) * scale_{factor} - 0.5 else: input : (N,C,D_in,H_in,W_in) output: (N,C,D_out,H_out,W_out) where: D_out = D_{in} * scale_{factor} H_out = H_{in} * scale_{factor} W_out = W_{in} * scale_{factor} https://en.wikipedia.org/wiki/Linear_interpolation. For details of linear interpolation, please refer to Wikipedia: For details of nearest neighbor interpolation, please refer to Wikipedia: https://en.wikipedia.org/wiki/Nearest-neighbor_interpolation. For details of bilinear interpolation, please refer to Wikipedia: https://en.wikipedia.org/wiki/Bilinear_interpolation. For details of bicubic interpolation, please refer to Wikipedia: https://en.wikipedia.org/wiki/Bicubic_interpolation For details of trilinear interpolation, please refer to Wikipedia: https://en.wikipedia.org/wiki/Trilinear_interpolation. Parameters: x (Tensor): 3-D, 4-D or 5-D Tensor, its data type is float32, float64, or uint8, its data format is specified by :attr:`data_format`. size (list|tuple|Tensor|None): Output shape of image resize layer, the shape is (out_w, ) when input is a 3-D Tensor, the shape is (out_h, out_w) when input is a 4-D Tensor and is (out_d, out_h, out_w) when input is a 5-D Tensor. Default: None. If a list, each element can be an integer or a Tensor Variable of shape: [1]. If a Tensor Variable, its dimensions size should be a 1. scale_factor (float|Tensor|list|None): The multiplier for the input height or width. At least one of :attr:`out_shape` or :attr:`scale_factor` must be set. And :attr:`out_shape` has a higher priority than :attr:`scale_factor`.Has to match input size if it is a list. Default: None. mode (str): The resample method. It supports 'linear', 'nearst', 'bilinear', 'bicubic' and 'trilinear' currently. Default: 'nearest' align_corners(bool) : An optional bool, If True, the centers of the 4 corner pixels of the input and output tensors are aligned, preserving the values at the corner pixels. Default: False align_mode(int) : An optional for linear/bilinear/trilinear interpolation. Refer to the formula in the example above, it can be \'0\' for src_idx = scale_factor*(dst_indx+0.5)-0.5 , can be \'1\' for src_idx = scale_factor*dst_index. data_format (str, optional): Specify the data format of the input, and the data format of the output will be consistent with that of the input. An optional string from:`NCW`, `NWC`, `"NCHW"`, `"NHWC"`, `"NCDHW"`, `"NDHWC"`. The default is `"NCHW"`. When it is `"NCHW"`, the data is stored in the order of: `[batch_size, input_channels, input_height, input_width]`. When it is `"NCHW"`, the data is stored in the order of: `[batch_size, input_channels, input_depth, input_height, input_width]`. name(str, optional): The default value is None. Normally there is no need for user to set this property. For more information, please refer to :ref:`api_guide_Name` Returns: A 3-D Tensor of the shape (num_batches, channels, out_w) or (num_batches, out_w, channels), A 4-D Tensor of the shape (num_batches, channels, out_h, out_w) or (num_batches, out_h, out_w, channels), or 5-D Tensor of the shape (num_batches, channels, out_d, out_h, out_w) or (num_batches, out_d, out_h, out_w, channels). Raises: TypeError: size should be a list or tuple or Tensor. ValueError: The 'mode' of image_resize can only be 'linear', 'bilinear', 'trilinear', 'bicubic', or 'nearest' currently. ValueError: 'linear' only support 3-D tensor. ValueError: 'bilinear', 'bicubic' and 'nearest' only support 4-D tensor. ValueError: 'trilinear' only support 5-D tensor. ValueError: One of size and scale_factor must not be None. ValueError: size length should be 1 for input 3-D tensor. ValueError: size length should be 2 for input 4-D tensor. ValueError: size length should be 3 for input 5-D tensor. ValueError: scale_factor should be greater than zero. TypeError: align_corners should be a bool value ValueError: align_mode can only be '0' or '1' ValueError: data_format can only be 'NCW', 'NWC', 'NCHW', 'NHWC', 'NCDHW' or 'NDHWC'. Examples: .. code-block:: python import paddle import paddle.nn as nn import numpy as np paddle.disable_static() input_data = np.random.rand(2,3,6,10).astype("float32") upsample_out = paddle.nn.UpSample(size=[12,12]) input = paddle.to_tensor(input_data) output = upsample_out(x=input) print(output.shape) # [2L, 3L, 12L, 12L] """ def __init__(self, size=None, scale_factor=None, mode='nearest', align_corners=False, align_mode=0, data_format='NCHW', name=None): super(UpSample, self).__init__() self.size = size self.scale_factor = scale_factor self.mode = mode.lower() self.align_corners = align_corners self.align_mode = align_mode self.data_format = data_format self.name = name def forward(self, x): out = F.interpolate( x, size=self.size, scale_factor=self.scale_factor, mode=self.mode, align_corners=self.align_corners, align_mode=self.align_mode, data_format=self.data_format, name=self.name) return out class UpsamplingNearest2d(layers.Layer): """ This op upsamples a batch of images, using nearest neighbours' pixel values. The input must be a 4-D Tensor of the shape (num_batches, channels, in_h, in_w), and the upsampling only applies on the two dimensions(height and width). Nearest neighbor interpolation is to perform nearest neighbor interpolation in both the 3rd dimension(in height direction) and the 4th dimension(in width direction) on input tensor. For details of nearest neighbor interpolation, please refer to Wikipedia: https://en.wikipedia.org/wiki/Nearest-neighbor_interpolation. x (Tensor): 4-D Tensor, its data type is float32, float64, or uint8, its data format is specified by :attr:`data_format`. size (list|tuple|Tensor|None): Output shape of image resize layer, the shape is (out_h, out_w) when input is a 4-D Tensor. Default: None. If a list, each element can be an integer or a Tensor Variable of shape: [1]. If a Tensor Variable, its dimensions size should be a 1. scale_factor (float|int|list|Tensor|None): The multiplier for the input height or width. At least one of :attr:`out_shape` or :attr:`scale_factor` must be set. And :attr:`out_shape` has a higher priority than :attr:`scale_factor`. Default: None. Has to match input size if it is a list. data_format (str, optional): Specify the data format of the input, and the data format of the output will be consistent with that of the input. An optional string from:`NCW`, `NWC`, `"NCHW"`, `"NHWC"`, `"NCDHW"`, `"NDHWC"`. The default is `"NCHW"`. When it is `"NCHW"`, the data is stored in the order of: `[batch_size, input_channels, input_height, input_width]`. When it is `"NCHW"`, the data is stored in the order of: `[batch_size, input_channels, input_depth, input_height, input_width]`. name(str, optional): The default value is None. Normally there is no need for user to set this property. For more information, please refer to :ref:`api_guide_Name` Returns: A 4-D Tensor of the shape (num_batches, channels, out_h, out_w) or (num_batches, out_h, out_w, channels), Raises: TypeError: size should be a list or tuple or Tensor. ValueError: 'nearest' only support 4-D tensor. ValueError: One of size and scale_factor must not be None. ValueError: size length should be 2 for input 4-D tensor. ValueError: scale_factor should be greater than zero. ValueError: data_format can only be 'NCHW', 'NHWC'. Examples: .. code-block:: python import paddle import paddle.nn as nn import numpy as np paddle.disable_static() input_data = np.random.rand(2,3,6,10).astype("float32") upsample_out = paddle.nn.UpsamplingNearest2d(size=[12,12]) input = paddle.to_tensor(input_data) output = upsample_out(x=input) print(output.shape) # [2L, 3L, 12L, 12L] """ def __init__(self, size=None, scale_factor=None, data_format='NCHW', name=None): super(UpsamplingNearest2d, self).__init__() self.size = size self.scale_factor = scale_factor self.data_format = data_format self.name = name def forward(self, x): out = F.interpolate( x, size=self.size, scale_factor=self.scale_factor, mode='nearest', align_corners=False, align_mode=0, data_format=self.data_format, name=self.name) return out class UpsamplingBilinear2d(layers.Layer): """ This op upsamples a batch of images, using bilinear' pixel values. The input must be a 4-D Tensor of the shape (num_batches, channels, in_h, in_w), and the upsampling only applies on the two dimensions(height and width). Bilinear interpolation is an extension of linear interpolation for interpolating functions of two variables (e.g. H-direction and W-direction in this op) on a rectilinear 2D grid. The key idea is to perform linear interpolation first in one direction, and then again in the other direction. For details of bilinear interpolation, please refer to Wikipedia: https://en.wikipedia.org/wiki/Bilinear_interpolation. x (Tensor): 4-D Tensor, its data type is float32, float64, or uint8, its data format is specified by :attr:`data_format`. size (list|tuple|Tensor|None): Output shape of image resize layer, the shape is (out_h, out_w) when input is a 4-D Tensor. Default: None. If a list, each element can be an integer or a Tensor Variable of shape: [1]. If a Tensor Variable, its dimensions size should be a 1. scale_factor (float|int|list|Tensor|None): The multiplier for the input height or width. At least one of :attr:`out_shape` or :attr:`scale_factor` must be set. And :attr:`out_shape` has a higher priority than :attr:`scale_factor`. Default: None. Has to match input size if it is a list. data_format (str, optional): Specify the data format of the input, and the data format of the output will be consistent with that of the input. An optional string from:`NCW`, `NWC`, `"NCHW"`, `"NHWC"`, `"NCDHW"`, `"NDHWC"`. The default is `"NCHW"`. When it is `"NCHW"`, the data is stored in the order of: `[batch_size, input_channels, input_height, input_width]`. When it is `"NCHW"`, the data is stored in the order of: `[batch_size, input_channels, input_depth, input_height, input_width]`. name(str, optional): The default value is None. Normally there is no need for user to set this property. For more information, please refer to :ref:`api_guide_Name` Returns: A 4-D Tensor of the shape (num_batches, channels, out_h, out_w) or (num_batches, out_h, out_w, channels), Raises: TypeError: size should be a list or tuple or Tensor. ValueError: 'bilinear' only support 4-D tensor. ValueError: One of size and scale_factor must not be None. ValueError: size length should be 2 for input 4-D tensor. ValueError: scale_factor should be greater than zero. ValueError: data_format can only be 'NCHW', 'NHWC'. Examples: .. code-block:: python import paddle import paddle.nn as nn import numpy as np paddle.disable_static() input_data = np.random.rand(2,3,6,10).astype("float32") upsample_out = paddle.nn.UpsamplingBilinear2d(size=[12,12]) input = paddle.to_tensor(input_data) output = upsample_out(x=input) print(output.shape) # [2L, 3L, 12L, 12L] """ def __init__(self, size=None, scale_factor=None, data_format='NCHW', name=None): super(UpsamplingBilinear2d, self).__init__() self.size = size self.scale_factor = scale_factor self.data_format = data_format self.name = name def forward(self, x): out = F.interpolate( x, size=self.size, scale_factor=self.scale_factor, mode='bilinear', align_corners=True, align_mode=0, data_format=self.data_format, name=self.name) return out class Pad2D(layers.Layer): """ :alias_main: paddle.nn.Pad2D :alias: paddle.nn.Pad2D,paddle.nn.layer.Pad2D,paddle.nn.layer.common.Pad2D This interface is used to construct a callable object of the ``Pad2D`` class. The Pad2D layer pads the input tensor boundaries according to 'paddings' and 'mode'. If mode is 'reflect', paddings[0] and paddings[1] must be no greater than height-1. And the width dimension has the same condition. Parameters: paddings (int | List[int32]): The padding size. If padding is a int, uses the same padding in all boundaries, if padding is a List, it must contain four integers, (padding_top, padding_bottom, padding_left, padding_right). Default is [0, 0, 0, 0]. mode (str): Three modes: 'constant' (default), 'reflect', 'edge' . When in 'constant' mode, this op uses a constant value to pad the input tensor. When in 'reflect' mode, uses reflection of the input boundaries to pad the input tensor. When in 'edge' mode, uses input boundaries to pad the input tensor. Default is 'constant' pad_value (float32): The value to fill the padded areas in 'constant' mode . Default is 0.0 data_format (str): An string from: "NHWC", "NCHW". Specify the data format of the input data. Default is "NCHW" Returns: None Examples: .. code-block:: text Input = [[[[1., 2., 3.], [4., 5., 6.]]]] Case 0: paddings = [0, 1, 2, 3], mode = 'constant' pad_value = 0 Out = [[[[0., 0., 1., 2., 3., 0., 0., 0.], [0., 0., 4., 5., 6., 0., 0., 0.], [0., 0., 0., 0., 0., 0., 0., 0.]]]] Case 1: paddings = [0, 1, 2, 1], mode = 'reflect' Out = [[[[3., 2., 1., 2., 3., 2.], [6., 5., 4., 5., 6., 5.], [3., 2., 1., 2., 3., 2.]]]] Case 2: paddings = [0, 1, 2, 1], mode = 'edge' Out = [[[[1., 1., 1., 2., 3., 3.], [4., 4., 4., 5., 6., 6.], [4., 4., 4., 5., 6., 6.]]]] Code Examples: .. code-block:: python import paddle.fluid as fluid import paddle.nn as nn import numpy as np data = np.ones((2, 2, 2, 2)).astype('float32') my_pad = nn.Pad2D(paddings=[1, 1, 1, 1]) with fluid.dygraph.guard(): data = fluid.dygraph.to_variable(data) result = my_pad(data) """ def __init__(self, paddings=0, mode='constant', pad_value=0.0, data_format="NCHW"): super(Pad2D, self).__init__() self._mode = mode self._pad_value = pad_value self._data_format = data_format self._paddings = [paddings] * 4 if isinstance(paddings, int) else paddings def forward(self, input): return F.pad2d( input, paddings=self._paddings, mode=self._mode, pad_value=self._pad_value, data_format=self._data_format) class Bilinear(layers.Layer): """ This layer performs bilinear on two inputs. .. math:: out_{i} = x1 * W_{i} * {x2^\mathrm{T}}, i=0,1,...,size-1 out = out + b In this formula: - :math:`x1`: the first input contains in1_features elements, shape is [batch_size, in1_features]. - :math:`x2`: the second input contains in2_features elements, shape is [batch_size, in2_features]. - :math:`W_{i}`: the i-th learned weight, shape is [in1_features, in2_features], and learned weight's shape is [out_features, in1_features, in2_features]. - :math:`out_{i}`: the i-th element of out, shape is [batch_size, out_features]. - :math:`b`: the learned bias, shape is [1, out_features]. - :math:`x2^\mathrm{T}`: the transpose of :math:`x2`. Parameters: in1_features (int): The dimension of each first input(`x1`). in2_features (int): The dimension of each second input(`x2`). out_features (int): The dimension of output of this layer. weight_attr (ParamAttr, optional): The parameter attribute for the learnable w, parameters/weights of this layer. The default value is None. bias_attr (ParamAttr, optional): The parameter attribute for the bias of this layer. If it is set to False, no bias will be added to the output units. If it is set to None, the bias is initialized zero. The default value is None. name (str, optional): The default value is None. Normally there is no need for user to set this property. For more information, please refer to :ref:`api_guide_Name`. Default: None. Attribute: **weight** (Parameter): the learnable weights of this layer. **bias** (Parameter): the learnable bias of this layer. Returns: Tensor: A 2-D Tensor of shape [batch_size, out_features]. Examples: .. code-block:: python import paddle import numpy paddle.disable_static() layer1 = numpy.random.random((5, 5)).astype('float32') layer2 = numpy.random.random((5, 4)).astype('float32') bilinear = paddle.nn.Bilinear( in1_features=5, in2_features=4, out_features=1000) result = bilinear(paddle.to_tensor(layer1), paddle.to_tensor(layer2)) # result shape [5, 1000] """ def __init__(self, in1_features, in2_features, out_features, weight_attr=None, bias_attr=None, name=None): super(Bilinear, self).__init__() self._weight_attr = weight_attr self._bias_attr = bias_attr self._name = name self._in1_features = in1_features self._in2_features = in2_features self._out_features = out_features self._dtype = self._helper.get_default_dtype() weight_shape = [ self._out_features, self._in1_features, self._in2_features ] self.weight = self.create_parameter( attr=self._weight_attr, shape=weight_shape, dtype=self._dtype, is_bias=False) bias_shape = [1, self._out_features] self.bias = self.create_parameter( attr=self._bias_attr, shape=bias_shape, dtype=self._dtype, is_bias=True) def forward(self, x1, x2): return F.bilinear(x1, x2, self.weight, self.bias, self._name) class Dropout(layers.Layer): """ Dropout is a regularization technique for reducing overfitting by preventing neuron co-adaption during training as described in the paper: `Improving neural networks by preventing co-adaptation of feature detectors `_ The dropout operator randomly sets the outputs of some units to zero, while upscale others according to the given dropout probability. See ``paddle.nn.functional.dropout`` for more details. In dygraph mode, please use ``eval()`` to switch to evaluation mode, where dropout is disabled. Parameters: p (float | int): Probability of setting units to zero. Default: 0.5 axis (int | list): The axis along which the dropout is performed. Default None. mode(str, optional): ['upscale_in_train'(default) | 'downscale_in_infer'] 1. upscale_in_train(default), upscale the output at training time - train: out = input * mask / ( 1.0 - p ) - inference: out = input 2. downscale_in_infer, downscale the output at inference - train: out = input * mask - inference: out = input * (1.0 - p) name (str, optional): Name for the operation (optional, default is None). For more information, please refer to :ref:`api_guide_Name`. Shape: - input: N-D tensor. - output: N-D tensor, the same shape as input. Examples: .. code-block:: python import paddle import numpy as np paddle.disable_static() x = np.array([[1,2,3], [4,5,6]]).astype('float32') x = paddle.to_tensor(x) m = paddle.nn.Dropout(p=0.5) y_train = m(x) m.eval() # switch the model to test phase y_test = m(x) print(x.numpy()) print(y_train.numpy()) print(y_test.numpy()) """ def __init__(self, p=0.5, axis=None, mode="upscale_in_train", name=None): super(Dropout, self).__init__() self.p = p self.axis = axis self.mode = mode self.name = name def forward(self, input): out = F.dropout( input, p=self.p, axis=self.axis, training=self.training, mode=self.mode, name=self.name) return out class Dropout2d(layers.Layer): """ Randomly zero out entire channels (in the batched input 4d tensor with the shape `NCHW` , a channel is a 2D feature map with the shape `HW`). Each channel will be zeroed out independently on every forward call with probability `p` using samples from a Bernoulli distribution. Dropout2d will help promote independence between feature maps as described in the paper: `Efficient Object Localization Using Convolutional Networks `_ See ``paddle.nn.functional.dropout2d`` for more details. In dygraph mode, please use ``eval()`` to switch to evaluation mode, where dropout is disabled. Parameters: p (float, optional): Probability of setting units to zero. Default: 0.5 data_format (str, optional): Specify the data format of the input, and the data format of the output will be consistent with that of the input. An optional string from: `NCHW`, `NHWC`. The default is `NCHW`. When it is `NCHW`, the data is stored in the order of: [batch_size, input_channels, input_height, input_width]. name (str, optional): Name for the operation (optional, default is None). For more information, please refer to :ref:`api_guide_Name`. Shape: - input: 4-D tensor. - output: 4-D tensor, the same shape as input. Examples: .. code-block:: python import paddle import numpy as np paddle.disable_static() x = np.random.random(size=(2, 3, 4, 5)).astype('float32') x = paddle.to_tensor(x) m = paddle.nn.Dropout2d(p=0.5) y_train = m(x) m.eval() # switch the model to test phase y_test = m(x) print(x.numpy()) print(y_train.numpy()) print(y_test.numpy()) """ def __init__(self, p=0.5, data_format='NCHW', name=None): super(Dropout2d, self).__init__() self.p = p self.data_format = data_format self.name = name def forward(self, input): out = F.dropout2d( input, p=self.p, training=self.training, data_format=self.data_format, name=self.name) return out class Dropout3d(layers.Layer): """ Randomly zero out entire channels (in the batched input 5d tensor with the shape `NCDHW` , a channel is a 3D feature map with the shape `DHW` ). Each channel will be zeroed out independently on every forward call with probability `p` using samples from a Bernoulli distribution. Dropout3d will help promote independence between feature maps as described in the paper: `Efficient Object Localization Using Convolutional Networks `_ See ``paddle.nn.functional.dropout3d`` for more details. In dygraph mode, please use ``eval()`` to switch to evaluation mode, where dropout is disabled. Parameters: p (float | int): Probability of setting units to zero. Default: 0.5 data_format (str, optional): Specify the data format of the input, and the data format of the output will be consistent with that of the input. An optional string from: `NCDHW`, `NDHWC`. The default is `NCDHW`. When it is `NCDHW`, the data is stored in the order of: [batch_size, input_channels, input_depth, input_height, input_width]. name (str, optional): Name for the operation (optional, default is None). For more information, please refer to :ref:`api_guide_Name`. Shape: - input: 5-D tensor. - output: 5-D tensor, the same shape as input. Examples: .. code-block:: python import paddle import numpy as np paddle.disable_static() x = np.random.random(size=(2, 3, 4, 5, 6)).astype('float32') x = paddle.to_tensor(x) m = paddle.nn.Dropout3d(p=0.5) y_train = m(x) m.eval() # switch the model to test phase y_test = m(x) print(x.numpy()) print(y_train.numpy()) print(y_test.numpy()) """ def __init__(self, p=0.5, data_format='NCDHW', name=None): super(Dropout3d, self).__init__() self.p = p self.data_format = data_format self.name = name def forward(self, input): out = F.dropout3d( input, p=self.p, training=self.training, data_format=self.data_format, name=self.name) return out class AlphaDropout(layers.Layer): """ Alpha Dropout is a type of Dropout that maintains the self-normalizing property. For an input with zero mean and unit standard deviation, the output of Alpha Dropout maintains the original mean and standard deviation of the input. Alpha Dropout fits well to SELU activate function by randomly setting activations to the negative saturation value. For more information, please refer to: `Self-Normalizing Neural Networks `_ In dygraph mode, please use ``eval()`` to switch to evaluation mode, where dropout is disabled. Parameters: p (float | int): Probability of setting units to zero. Default: 0.5 name (str, optional): Name for the operation (optional, default is None). For more information, please refer to :ref:`api_guide_Name`. Shape: - input: N-D tensor. - output: N-D tensor, the same shape as input. Examples: .. code-block:: python import paddle import numpy as np paddle.disable_static() x = np.array([[-1, 1], [-1, 1]]).astype('float32') x = paddle.to_tensor(x) m = paddle.nn.AlphaDropout(p=0.5) y_train = m(x) m.eval() # switch the model to test phase y_test = m(x) print(x.numpy()) print(y_train.numpy()) # [[-0.10721093, 1.6655989 ], [-0.7791938, -0.7791938]] (randomly) print(y_test.numpy()) """ def __init__(self, p=0.5, name=None): super(AlphaDropout, self).__init__() self.p = p self.name = name def forward(self, input): out = F.alpha_dropout( input, p=self.p, training=self.training, name=self.name) return out class ReflectionPad1d(layers.Layer): """ This interface is used to construct a callable object of the ``ReflectionPad1d`` class. Uses reflection of the input boundaries to pad the input tensor. Parameters: padding (Tensor | List[int32]): The padding size with data type int32. [len(padding)/2] dimensions of input will be padded. The pad has the form (pad_left, pad_right). data_format (str): An string from: "NCL", "NLC". Specify the data format of the input data. Default is "NCL" name (str, optional) : The default value is None. Normally there is no need for user to set this property. For more information, please refer to :ref:`api_guide_Name`. Returns: None Examples: .. code-block:: text x = [[[1., 2., 3.], [4., 5., 6.]]] padding = [1, 2], Out = [[[2. 1. 2. 3. 2. 1.] [5. 4. 5. 6. 5. 4.]]] Code Examples: .. code-block:: python import paddle import paddle.nn as nn import numpy as np paddle.disable_static() input_shape = (1, 2, 3) pad = [1, 2] data = np.arange(np.prod(input_shape), dtype=np.float32).reshape(input_shape) + 1 my_pad = nn.ReflectionPad1d(padding=pad) data = paddle.to_tensor(data) result = my_pad(data) print(result.numpy()) # [[[2. 1. 2. 3. 2. 1.] # [5. 4. 5. 6. 5. 4.]]] """ def __init__(self, padding, data_format="NCL", name=None): super(ReflectionPad1d, self).__init__() self._mode = "reflect" self._data_format = data_format self._pad = padding self._name = name def forward(self, x): return F.pad(x, pad=self._pad, mode=self._mode, data_format=self._data_format, name=self._name) class ReplicationPad1d(layers.Layer): """ This interface is used to construct a callable object of the ``ReplicationPad1d`` class. Uses input boundaries to pad the input tensor. Parameters: padding (Tensor | List[int32]): The padding size with data type int32. [len(padding)/2] dimensions of input will be padded. The pad has the form (pad_left, pad_right). data_format (str): An string from: "NCL", "NLC". Specify the data format of the input data. Default is "NCL" name (str, optional) : The default value is None. Normally there is no need for user to set this property. For more information, please refer to :ref:`api_guide_Name`. Returns: None Examples: .. code-block:: text x = [[[1., 2., 3.], [4., 5., 6.]]] padding = [1, 2], Out = [[[2. 1. 2. 3. 2. 1.] [5. 4. 5. 6. 5. 4.]]] Code Examples: .. code-block:: python import paddle import paddle.nn as nn import numpy as np paddle.disable_static() input_shape = (1, 2, 3) pad = [1, 2] data = np.arange(np.prod(input_shape), dtype=np.float32).reshape(input_shape) + 1 my_pad = nn.ReplicationPad1d(padding=pad) data = paddle.to_tensor(data) result = my_pad(data) print(result.numpy()) # [[[1. 1. 2. 3. 3. 3.] # [1. 4. 5. 6. 6. 6.]]] """ def __init__(self, padding, data_format="NCL", name=None): super(ReplicationPad1d, self).__init__() self._mode = "replicate" self._data_format = data_format self._pad = padding self._name = name def forward(self, x): return F.pad(x, pad=self._pad, mode=self._mode, data_format=self._data_format, name=self._name) class ConstantPad1d(layers.Layer): """ This interface is used to construct a callable object of the ``ConstantPad1d`` class. Uses a constant value to pad the input tensor. Parameters: padding (Tensor | List[int32]): The padding size with data type int32. [len(padding)/2] dimensions of input will be padded. The pad has the form (pad_left, pad_right). value (float32): The value to fill the padded areas. Default is 0.0 data_format (str): An string from: "NCL", "NLC". Specify the data format of the input data. Default is "NCL" name (str, optional) : The default value is None. Normally there is no need for user to set this property. For more information, please refer to :ref:`api_guide_Name`. Returns: None Examples: .. code-block:: text x = [[[1., 2., 3.], [4., 5., 6.]]] padding = [1, 2], value = 0.0 Out = [[[0. 1. 2. 3. 0. 0.] [0. 4. 5. 6. 0. 0.]]] Code Examples: .. code-block:: python import paddle import paddle.nn as nn import numpy as np paddle.disable_static() input_shape = (1, 2, 3) pad = [1, 2] data = np.arange(np.prod(input_shape), dtype=np.float32).reshape(input_shape) + 1 my_pad = nn.ConstantPad1d(padding=pad) data = paddle.to_tensor(data) result = my_pad(data) print(result.numpy()) # [[[0. 1. 2. 3. 0. 0.] # [0. 4. 5. 6. 0. 0.]]] """ def __init__(self, padding, value=0.0, data_format="NCL", name=None): super(ConstantPad1d, self).__init__() self._mode = "constant" self._data_format = data_format self._pad = padding self._value = value self._name = name def forward(self, x): return F.pad(x, pad=self._pad, mode=self._mode, value=self._value, data_format=self._data_format, name=self._name) class ConstantPad2d(layers.Layer): """ This interface is used to construct a callable object of the ``ConstantPad2d`` class. Uses a constant value to pad the input tensor. Parameters: padding (Tensor | List[int32]): The padding size with data type int32. [len(padding)/2] dimensions of input will be padded. The pad has the form (pad_left, pad_right, pad_top, pad_bottom). value (float32): The value to fill the padded areas. Default is 0.0 data_format (str): An string from: "NCHW", "NHWC". Specify the data format of the input data. Default is "NCHW" name (str, optional) : The default value is None. Normally there is no need for user to set this property. For more information, please refer to :ref:`api_guide_Name`. Returns: None Examples: .. code-block:: text x = [[[[1., 2., 3.], [4., 5., 6.]]]] padding = [1, 1, 0, 0] value = 0.0 Out = [[[[0. 1. 2. 3. 0.] [0. 4. 5. 6. 0.]]]] Code Examples: .. code-block:: python import paddle import paddle.nn as nn import numpy as np paddle.disable_static() input_shape = (1, 1, 2, 3) pad = [1, 0, 1, 2] data = np.arange(np.prod(input_shape), dtype=np.float32).reshape(input_shape) + 1 my_pad = nn.ConstantPad2d(padding=pad) data = paddle.to_tensor(data) result = my_pad(data) print(result.numpy()) # [[[[0. 0. 0. 0.] # [0. 1. 2. 3.] # [0. 4. 5. 6.] # [0. 0. 0. 0.] # [0. 0. 0. 0.]]]] """ def __init__(self, padding, value=0.0, data_format="NCHW", name=None): super(ConstantPad2d, self).__init__() self._mode = "constant" self._data_format = data_format self._pad = padding self._value = value self._name = name def forward(self, x): return F.pad(x, pad=self._pad, mode=self._mode, value=self._value, data_format=self._data_format, name=self._name) class ZeroPad2d(layers.Layer): """ This interface is used to construct a callable object of the ``ZeroPad2d`` class. Uses 0 to pad the input tensor. Parameters: padding (Variable | List[int32]): The padding size with data type int32. [len(padding)/2] dimensions of input will be padded. The pad has the form (pad_left, pad_right, pad_top, pad_bottom). data_format (str): An string from: "NCHW", "NHWC". Specify the data format of the input data. Default is "NCHW" name (str, optional) : The default value is None. Normally there is no need for user to set this property. For more information, please refer to :ref:`api_guide_Name`. Returns: None Examples: .. code-block:: text x = [[[[1., 2., 3.], [4., 5., 6.]]]] padding = [1, 1, 0, 0] Out = [[[[0. 1. 2. 3. 0.] [0. 4. 5. 6. 0.]]]] Code Examples: .. code-block:: python import paddle import paddle.nn as nn import numpy as np paddle.disable_static() input_shape = (1, 1, 2, 3) pad = [1, 0, 1, 2] data = np.arange(np.prod(input_shape), dtype=np.float32).reshape(input_shape) + 1 my_pad = nn.ZeroPad2d(padding=pad) data = paddle.to_tensor(data) result = my_pad(data) print(result.numpy()) # [[[[0. 0. 0. 0.] # [0. 1. 2. 3.] # [0. 4. 5. 6.] # [0. 0. 0. 0.] # [0. 0. 0. 0.]]]] """ def __init__(self, padding, data_format="NCHW", name=None): super(ZeroPad2d, self).__init__() self._mode = "constant" self._data_format = data_format self._pad = padding self._name = name def forward(self, x): return F.pad(x, pad=self._pad, mode=self._mode, data_format=self._data_format, name=self._name) class ReplicationPad2d(layers.Layer): """ This interface is used to construct a callable object of the ``ReplicationPad2d`` class. Uses input boundaries to pad the input tensor. Parameters: padding (Tensor | List[int32]): The padding size with data type int32. [len(padding)/2] dimensions of input will be padded. The pad has the form (pad_left, pad_right, pad_top, pad_bottom). data_format (str): An string from: "NCHW", "NHWC". Specify the data format of the input data. Default is "NCHW" name (str, optional) : The default value is None. Normally there is no need for user to set this property. For more information, please refer to :ref:`api_guide_Name`. Returns: None Examples: .. code-block:: text x = [[[[1., 2., 3.], [4., 5., 6.]]]] padding = [1, 1, 0, 0] Out = [[[[1. 1. 2. 3. 3.] [4. 4. 5. 6. 6.]]]] Code Examples: .. code-block:: python import paddle import paddle.nn as nn import numpy as np paddle.disable_static() input_shape = (1, 1, 2, 3) pad = [1, 0, 1, 2] data = np.arange(np.prod(input_shape), dtype=np.float32).reshape(input_shape) + 1 my_pad = nn.ReplicationPad2d(padding=pad) data = paddle.to_tensor(data) result = my_pad(data) print(result.numpy()) # [[[[1. 1. 2. 3.] # [1. 1. 2. 3.] # [4. 4. 5. 6.] # [4. 4. 5. 6.] # [4. 4. 5. 6.]]]] """ def __init__(self, padding, data_format="NCHW", name=None): super(ReplicationPad2d, self).__init__() self._mode = "replicate" self._data_format = data_format self._pad = padding self._name = name def forward(self, x): return F.pad(x, pad=self._pad, mode=self._mode, data_format=self._data_format, name=self._name) class ReflectionPad2d(layers.Layer): """ This interface is used to construct a callable object of the ``ReflectionPad2d`` class. Uses reflection of the input boundaries to pad the input tensor. Parameters: padding (Variable | List[int32]): The padding size with data type int32. [len(padding)/2] dimensions of input will be padded. The pad has the form (pad_left, pad_right, pad_top, pad_bottom). data_format (str): An string from: "NCHW", "NHWC". Specify the data format of the input data. Default is "NCHW" name (str, optional) : The default value is None. Normally there is no need for user to set this property. For more information, please refer to :ref:`api_guide_Name`. Returns: None Examples: .. code-block:: text x = [[[[1., 2., 3.], [4., 5., 6.]]]] padding = [1, 1, 0, 0] Out = [[[[2. 1. 2. 3. 2.] [5. 4. 5. 6. 5.]]]] Code Examples: .. code-block:: python import paddle import paddle.nn as nn import numpy as np paddle.disable_static() input_shape = (1, 1, 4, 3) pad = [1, 0, 1, 2] data = np.arange(np.prod(input_shape), dtype=np.float32).reshape(input_shape) + 1 my_pad = nn.ReflectionPad2d(padding=pad) data = paddle.to_tensor(data) result = my_pad(data) print(result.numpy()) # [[[[ 5. 4. 5. 6.] # [ 2. 1. 2. 3.] # [ 5. 4. 5. 6.] # [ 8. 7. 8. 9.] # [11. 10. 11. 12.] # [ 8. 7. 8. 9.] # [ 5. 4. 5. 6.]]]] """ def __init__(self, padding, data_format="NCHW", name=None): super(ReflectionPad2d, self).__init__() self._mode = "reflect" self._data_format = data_format self._pad = padding self._name = name def forward(self, x): return F.pad(x, pad=self._pad, mode=self._mode, data_format=self._data_format, name=self._name) class ConstantPad3d(layers.Layer): """ This interface is used to construct a callable object of the ``ConstantPad3d`` class. Uses a constant value to pad the input tensor. Parameters: padding (Tensor | List[int32]): The padding size with data type int32. [len(padding)/2] dimensions of input will be padded. The pad has the form (pad_left, pad_right, pad_top, pad_bottom, pad_front, pad_back). value (float32): The value to fill the padded areas. Default is 0.0 data_format (str): An string from: "NCDHW", "NDHWC". Specify the data format of the input data. Default is "NCDHW" name (str, optional) : The default value is None. Normally there is no need for user to set this property. For more information, please refer to :ref:`api_guide_Name`. Returns: None Examples: .. code-block:: text x = [[[[[1., 2., 3.], [4., 5., 6.]]]]] padding = [1, 2, 0, 0, 0, 0] value = 0.0 Out = [[[[[0. 1. 2. 3. 0. 0.] [0. 4. 5. 6. 0. 0.]]]]] Code Examples: .. code-block:: python import paddle import paddle.nn as nn import numpy as np paddle.disable_static() input_shape = (1, 1, 1, 2, 3) pad = [1, 0, 1, 2, 0, 0] data = np.arange(np.prod(input_shape), dtype=np.float32).reshape(input_shape) + 1 my_pad = nn.ConstantPad3d(padding=pad) data = paddle.to_tensor(data) result = my_pad(data) print(result.numpy()) # [[[[[0. 0. 0. 0.] # [0. 1. 2. 3.] # [0. 4. 5. 6.] # [0. 0. 0. 0.] # [0. 0. 0. 0.]]]]] """ def __init__(self, padding, value=0.0, data_format="NCDHW", name=None): super(ConstantPad3d, self).__init__() self._mode = "constant" self._data_format = data_format self._pad = padding self._value = value self._name = name def forward(self, x): return F.pad(x, pad=self._pad, mode=self._mode, value=self._value, data_format=self._data_format, name=self._name) class ReplicationPad3d(layers.Layer): """ This interface is used to construct a callable object of the ``ReplicationPad3d`` class. Uses input boundaries to pad the input tensor. Parameters: padding (Tensor | List[int32]): The padding size with data type int32. [len(padding)/2] dimensions of input will be padded. The pad has the form (pad_left, pad_right, pad_top, pad_bottom, pad_front, pad_back). data_format (str): An string from: "NCDHW", "NDHWC". Specify the data format of the input data. Default is "NCDHW" name (str, optional) : The default value is None. Normally there is no need for user to set this property. For more information, please refer to :ref:`api_guide_Name`. Returns: None Examples: .. code-block:: text x = [[[[[1., 2., 3.], [4., 5., 6.]]]]] padding = [1, 2, 0, 0, 0, 0] Out = [[[[[1. 1. 2. 3. 3. 3.] [4. 4. 5. 6. 6. 6.]]]]] Code Examples: .. code-block:: python import paddle import paddle.nn as nn import numpy as np paddle.disable_static() input_shape = (1, 1, 1, 2, 3) pad = [1, 0, 1, 2, 0, 0] data = np.arange(np.prod(input_shape), dtype=np.float32).reshape(input_shape) + 1 my_pad = nn.ReplicationPad3d(padding=pad) data = paddle.to_tensor(data) result = my_pad(data) print(result.numpy()) # [[[[[1. 1. 2. 3.] # [1. 1. 2. 3.] # [4. 4. 5. 6.] # [4. 4. 5. 6.] # [4. 4. 5. 6.]]]]] """ def __init__(self, padding, data_format="NCDHW", name=None): super(ReplicationPad3d, self).__init__() self._mode = "replicate" self._data_format = data_format self._pad = padding self._name = name def forward(self, x): return F.pad(x, pad=self._pad, mode=self._mode, data_format=self._data_format, name=self._name) class CosineSimilarity(layers.Layer): """ This interface is used to compute cosine similarity between x1 and x2 along axis. Parameters: axis (int): Dimension of vectors to compute cosine similarity. Default is 1. eps(float): Small value to avoid division by zero. Default is 1e-8. Returns: None Examples: .. code-block:: text Case 0: x1 = [[0.8024077 0.9927354 0.27238318 0.8344984 ] [0.48949873 0.5797396 0.65444374 0.66510963] [0.1031398 0.9614342 0.08365563 0.6796464 ] [0.10760343 0.7461209 0.7726148 0.5801006 ]] x2 = [[0.62913156 0.1536727 0.9847992 0.04591406] [0.9098952 0.15715368 0.8671125 0.3156102 ] [0.4427798 0.54136837 0.5276275 0.32394758] [0.3769419 0.8535014 0.48041078 0.9256797 ]] axis = 1 eps = 1e-8 Out: [0.5275037 0.8368967 0.75037485 0.9245899] Code Examples: .. code-block:: python import paddle import paddle.nn as nn import numpy as np paddle.disable_static() np.random.seed(0) x1 = np.random.rand(2,3) x2 = np.random.rand(2,3) x1 = paddle.to_tensor(x1) x2 = paddle.to_tensor(x2) cos_sim_func = nn.CosineSimilarity(axis=0) result = cos_sim_func(x1, x2) print(result.numpy()) # [0.99806249 0.9817672 0.94987036] """ def __init__(self, axis=1, eps=1e-8): super(CosineSimilarity, self).__init__() self._axis = axis self._eps = eps def forward(self, x1, x2): return F.cosine_similarity(x1, x2, axis=self._axis, eps=self._eps) class Embedding(layers.Layer): """ :alias_main: paddle.nn.Embedding :alias: paddle.nn.Embedding,paddle.nn.layer.Embedding,paddle.nn.layer.common.Embedding :old_api: paddle.fluid.dygraph.Embedding **Embedding Layer** This interface is used to construct a callable object of the ``Embedding`` class. For specific usage, refer to code examples. It implements the function of the Embedding Layer. This layer 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. Parameters: num_embeddings (int): Just one element which indicate the size of the dictionary of embeddings. embedding_dim: Just one element which indicate the size of each embedding vector respectively. 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. 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_optimizer_AdadeltaOptimizer` , :ref:`api_optimizer_AdamaxOptimizer` , :ref:`api_optimizer_DecayedAdagradOptimizer` , :ref:`api_optimizer_FtrlOptimizer` , :ref:`api_optimizer_LambOptimizer` and :ref:`api_optimizer_LarsMomentumOptimizer` . In these case, is_sparse must be False. Default: False. weight_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. name(str|None): For detailed information, please refer to :ref:`api_guide_Name`. Usually name is no need to set and None by default. Attribute: **weight** (Parameter): the learnable weights of this layer. Returns: None Examples: .. code-block:: python import paddle import paddle.nn as nn import numpy as np paddle.disable_static() # example 1 inp_word = np.array([[2, 3, 5], [4, 2, 1]]).astype('int64') inp_word.shape # [2, 3] dict_size = 20 emb = nn.Embedding( dict_size, 32, sparse=False) """ def __init__(self, num_embeddings, embedding_dim, padding_idx=None, sparse=False, weight_attr=None, name=None): super(Embedding, self).__init__() self._num_embeddings = num_embeddings self._embedding_dim = embedding_dim self._sparse = sparse self._is_distributed = False self._padding_idx = -1 if padding_idx is None else padding_idx if padding_idx >= 0 else ( num_embeddings + padding_idx) self._dtype = self._helper.get_default_dtype() self._size = [self._num_embeddings, self._embedding_dim] self._weight_attr = weight_attr self._remote_prefetch = False self._name = name self._weight = self.create_parameter( attr=self._weight_attr, shape=self._size, dtype=self._dtype, is_bias=False) def forward(self, x): return F.embedding( x, weight=self._weight, padding_idx=self._padding_idx, sparse=self._sparse, name=self._name)