# 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. import warnings from ...fluid.layer_helper import LayerHelper from ...fluid.framework import in_dygraph_mode, convert_np_dtype_to_dtype_ from ...fluid import core from ...fluid.data_feeder import check_variable_and_dtype # TODO: define activation functions of neural network __all__ = [ # 'brelu', # 'elu', # 'erf', # 'gelu', # 'hard_shrink', # 'hard_sigmoid', # 'hard_swish', # 'hsigmoid', # 'leaky_relu', # 'logsigmoid', # 'maxout', # 'prelu', 'relu', # 'relu6', # 'selu', 'sigmoid', # 'soft_relu', # 'softmax', # 'softplus', # 'softshrink', # 'softsign', # 'swish', # 'tanh_shrink', # 'thresholded_relu', 'log_softmax', ] def relu(input, inplace=False, name=None): """ ReLU Activation. .. math: out = max(x, 0) Parameters: input (Variable): The input variable. A multi-dimension Tensor with type float16, float32, or float64. inplace (bool, optional): If inplace is True, the input and output of ``ReLU`` are the same variable. Otherwise, the input and output of ``ReLU`` are different variables. Default: False. Note that if x is more than one OPs' input, inplace must be False. 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: Output of relu operator, a Tensor with shape same as input Examples: .. code-block:: python import paddle.fluid as fluid import paddle.nn.functional as functional import numpy as np data = np.array([-2, 0, 1]).astype('float32') with fluid.dygraph.guard(): data = fluid.dygraph.to_variable(data) res = functional.relu(data) # [0, 0, 1] """ if in_dygraph_mode(): if inplace: warnings.warn( "Inplace on ReLU is not allowed and will be discarded in dygraph mode currently." ) return core.ops.relu(input) helper = LayerHelper('relu', **locals()) outs = input if inplace else helper.create_variable_for_type_inference( input.dtype) helper.append_op(type='relu', inputs={'X': [input]}, outputs={'Out': outs}) return outs def sigmoid(input, inplace=False, name=None): """ Sigmoid Activation. .. math: output = \frac{1}{1 + e^{-input}} Parameters: input (Variable): The input variable. A multi-dimension Tensor with type float16, float32, or float64. inplace (bool, optional): If inplace is True, the input and output are the same variable. Otherwise, the input and output of are different variables. Default: False. Note that if x is more than one OPs' input, inplace must be False. 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: Output of sigmoid operator, a Tensor with shape same as input Examples: .. code-block:: python import paddle.fluid as fluid import paddle.nn.functional as functional import numpy as np # In the static graph mode input = fluid.data(name="input", shape=[None, 4]) output = functional.sigmoid(input) place = fluid.CPUPlace() exe = fluid.Executor(place) exe.run(fluid.default_startup_program()) input_data = np.array([1.0, 2.0, 3.0, 4.0]).astype('float32') output_data = exe.run(feed={"input": input_data}, fetch_list=[output]) print(output_data) # [0.7310586, 0.880797, 0.95257413, 0.98201376] # In the dynamic graph mode with fluid.dygraph.guard(): input = fluid.dygraph.to_variable(input_data) output = functional.sigmoid(input) print(output) # [0.7310586, 0.880797, 0.95257413, 0.98201376] """ if in_dygraph_mode(): if inplace: warnings.warn( "Inplace on sigmoid is not allowed and will be discarded in dygraph mode currently." ) return core.ops.sigmoid(input) check_variable_and_dtype(input, 'X', ['float16', 'float32', 'float64'], 'sigmoid') helper = LayerHelper("sigmoid", **locals()) outputs = helper.create_variable_for_type_inference(input.dtype) helper.append_op( type='sigmoid', inputs={'X': [input]}, outputs={'Out': outputs}) return outputs def log_softmax(input, axis=None, dtype=None, name=None): """ This operator implements the log_softmax layer. The calculation process is as follows: .. math:: Out[i, j] = log(softmax(x)) = log(\\frac{\exp(X[i, j])}{\sum_j(exp(X[i, j])}) Parameters: input (Variable): The input variable. A multi-dimension Tensor with type float32, or float64. axis (int, optional): The index of dimension to perform softmax calculations, it should be in range :math:`[-1, rank-1]`, while :math:`rank` is the rank of input variable. Default: None. None and -1 means the last dimension. dtype (np.dtype|core.VarDesc.VarType|str): The desired data type of returned tensor. If specified, the input tensor is casted to dtype before the operation is performed. This is useful for preventing data type overflows. Default: None. Supported dtype: float32 or float64 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: Variable: ``Tensor`` indicates the output of softmax. The data type and shape are the same as ``input``. Examples: .. code-block:: python import paddle.fluid as fluid import paddle.nn.functional as F import numpy as np data = np.array([[[-2.0, 3.0, -4.0, 5.0], [3.0, -4.0, 5.0, -6.0], [-7.0, -8.0, 8.0, 9.0]], [[1.0, -2.0, -3.0, 4.0], [-5.0, 6.0, 7.0, -8.0], [6.0, 7.0, 8.0, 9.0]]]).astype('float32') with fluid.dygraph.guard(): data = fluid.dygraph.to_variable(data) res = F.log_softmax(data, -1) # [[[ -7.1278396 -2.1278396 -9.127839 -0.12783948] # [ -2.1270514 -9.127051 -0.12705144 -11.127051 ] # [-16.313261 -17.313261 -1.3132617 -0.31326184]] # [[ -3.0518122 -6.051812 -7.051812 -0.051812 ] # [-12.313267 -1.3132664 -0.3132665 -15.313267 ] # [ -3.4401896 -2.4401896 -1.4401896 -0.44018966]]] """ axis = -1 if axis is None else axis dtype = convert_np_dtype_to_dtype_(dtype) if dtype is not None else dtype if in_dygraph_mode(): outs_cast = input if dtype is None \ else core.ops.cast(input, 'in_dtype', input.dtype, 'out_dtype', dtype) outs_softmax = core.ops.softmax(outs_cast, 'axis', axis, 'use_cudnn', False) return core.ops.log(outs_softmax) helper = LayerHelper("log_softmax", **locals()) outs_cast = input if dtype is not None: outs_cast = helper.create_variable_for_type_inference(dtype) helper.append_op( type='cast', inputs={'X': input}, outputs={'Out': outs_cast}, attrs={'in_dtype': input.dtype, 'out_dtype': dtype}) outs_softmax = helper.create_variable_for_type_inference(outs_cast.dtype) helper.append_op( type='softmax', inputs={'X': outs_cast}, outputs={'Out': outs_softmax}, attrs={'axis': axis, 'use_cudnn': False}) outs_log = helper.create_variable_for_type_inference(outs_softmax.dtype) helper.append_op( type='log', inputs={'X': outs_softmax}, outputs={'Out': outs_log}) return outs_log