# 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 numpy as np from functools import partial, reduce from . import nn from .layer_function_generator import templatedoc from ..layer_helper import LayerHelper from ..framework import Variable from ..data_feeder import check_type_and_dtype from ..param_attr import ParamAttr from ..initializer import NumpyArrayInitializer __all__ = [ 'center_loss', 'bpr_loss', 'cross_entropy', 'square_error_cost', 'edit_distance', 'warpctc', 'nce', 'hsigmoid', 'sampled_softmax_with_cross_entropy', 'softmax_with_cross_entropy', 'rank_loss', 'margin_rank_loss', 'sigmoid_cross_entropy_with_logits', 'teacher_student_sigmoid_loss', 'huber_loss', 'kldiv_loss', 'npair_loss', 'mse_loss', ] kIgnoreIndex = -100 def center_loss(input, label, num_classes, alpha, param_attr, update_center=True): """ **Center loss Cost layer** This OP accepts input (deep features,the output of the last hidden layer) and target label and return the center loss cost. The average of the distances of each sample in the mini-batch from the center of the corresponding category is calculated as the center loss. For deep features, :math:`X`, and target labels, :math:`Y`, the equation is: .. math:: Out = \\frac{1}{2}(X - Y)^2 Args: input (Variable): a 2-D tensor with shape[N x M]. Its dtype should be float32 or float64. label (Variable): the groud truth which is a 2-D tensor with shape[N x 1],where N is the batch size. Its dtype should be int32. num_classes (int): the number of classification categories. alpha (float|Variable): learning rate of centers. param_attr (ParamAttr): Attribute initializer of centers. update_center (bool): whether to update value of center. Returns: Variable: 2-D tensor with shape [N * 1] Examples: .. code-block:: python import paddle.fluid as fluid input = fluid.data(name='x',shape=[20,30],dtype='float32') label = fluid.data(name='y',shape=[20,1],dtype='int64') num_classes = 1000 alpha = 0.01 param_attr = fluid.initializer.Xavier(uniform=False) center_loss=fluid.layers.center_loss(input=input, label=label, num_classes=1000, alpha=alpha, param_attr=fluid.initializer.Xavier(uniform=False), update_center=True) """ helper = LayerHelper('center_loss', **locals()) dtype = helper.input_dtype() centers_shape = [num_classes, input.shape[1]] centers_param = helper.create_parameter( attr=param_attr, shape=centers_shape, dtype=dtype) centers_param.stop_gradient = True if isinstance(alpha, Variable): alpha_param = alpha else: assert isinstance(alpha, float) alpha_param = helper.create_variable( name="centerloss_alpha", shape=[1], dtype="float32", type=core.VarDesc.VarType.LOD_TENSOR, persistable=True, stop_gradient=True, initializer=Constant(alpha)) centersdiff = helper.create_variable_for_type_inference(dtype=input.dtype) loss = helper.create_variable_for_type_inference(dtype=input.dtype) helper.append_op( type='center_loss', inputs={ 'X': [input], 'Label': [label], 'Centers': [centers_param], 'CenterUpdateRate': [alpha_param] }, outputs={ 'SampleCenterDiff': [centersdiff], 'Loss': [loss], 'CentersOut': [centers_param] }, attrs={'cluster_num': num_classes, 'need_update': update_center}) return loss def bpr_loss(input, label, name=None): """ **Bayesian Personalized Ranking Loss Operator** This operator belongs to pairwise ranking loss. Label is the desired item. The loss at a given point in one session is defined as: .. math:: Y[i] = 1/(N[i] - 1) * \sum_j{\log(\sigma(X[i, Label[i]]-X[i, j]))} Learn more details by reading paper . Args: input (Variable|list): a 2-D tensor with shape [N x D], where N is the batch size and D is the number of positive classes and negative classes This input is not probability but logits. label (Variable|list): the ground truth which is a 2-D tensor. `label` is a tensor with shape [N x 1]. name (str|None): A name for this layer(optional). If set None, the layer will be named automatically. Default: None. Returns: A 2-D tensor with shape [N x 1], the bpr loss. Examples: .. code-block:: python import paddle.fluid as fluid neg_size = 10 label = fluid.data( name="label", shape=[3, 1], dtype="int64") predict = fluid.data( name="predict", shape=[3, neg_size + 1], dtype="float32") cost = fluid.layers.bpr_loss(input=predict, label=label) """ helper = LayerHelper('bpr_loss', **locals()) out = helper.create_variable_for_type_inference(dtype=input.dtype) helper.append_op( type='bpr_loss', inputs={'X': [input], 'Label': [label]}, outputs={'Y': [out]}) return out def cross_entropy(input, label, soft_label=False, ignore_index=kIgnoreIndex): """ This operator computes the cross entropy between input and label. It supports both hard-label and and soft-label cross entropy computation. 1. Hard-label cross entropy: if soft_label=False, :math:`label[i_1, i_2, ..., i_k]` is the hard label of each sample. .. math:: output[i_1, i_2, ..., i_k]=-log(input[i_1, i_2, ..., i_k, j]), label[i_1, i_2, ..., i_k] = j, j != ignore\_index 2. Soft-label cross entropy: if soft_label=True, :math:`label[i_1, i_2, ..., i_k, j]` is the soft label of each sample corresponding to the j-th class. .. math:: output[i_1, i_2, ..., i_k]= -\sum_{j}label[i_1,i_2,...,i_k,j]*log(input[i_1, i_2, ..., i_k,j]) Args: input (Variable): a multidimensional Tensor with shape :math:`[N_1, N_2, ..., N_k, D]`, where the last dimension D is the class number. The data type should be float32 or float64. label (Variable): label value corresponding to input. If soft_label=False, the dimension of label should be :math:`[N_1, N_2, ..., N_k]` or :math:`[N_1, N_2, ..., N_k, 1]` , and its data type should be int64, and the value must be inside [0, D). If soft_label=True, the shape, data type of label should be the same with input, and the sum of soft label value of each sample should be 1. soft_label (bool): indicate whether label is soft. Default False, meaning that the label is hard. If soft_label=True, the label is soft. ignore_index (int): specify an ignorable label value. The ignored label would be omitted when computing. If it is a negative integer, no label would be ignored. Only valid when soft_label=False. Default -100. Returns: A Variable holding Tensor representing the cross entropy, whose data type is the same with input. If soft_label=False, the shape of output is the same with label. If soft_label=True, the shape of output is :math:`[N_1, N_2, ..., N_k, 1]` . Examples: .. code-block:: python import paddle.fluid as fluid class_num = 7 x = fluid.data(name='x', shape=[None, 3, 10], dtype='float32') label = fluid.data(name='label', shape=[None, 1], dtype='int64') predict = fluid.layers.fc(input=x, size=class_num, act='softmax') cost = fluid.layers.cross_entropy(input=predict, label=label) """ check_type_and_dtype(input, 'input', Variable, ['float16', 'float32', 'float64'], 'cross_entropy') if not soft_label: return cross_entropy2(input, label, ignore_index) helper = LayerHelper('cross_entropy', **locals()) out = helper.create_variable_for_type_inference(dtype=input.dtype) helper.append_op( type='cross_entropy', inputs={'X': [input], 'Label': [label]}, outputs={'Y': [out]}, attrs={"soft_label": soft_label, "ignore_index": ignore_index}) return out def cross_entropy2(input, label, ignore_index=kIgnoreIndex): helper = LayerHelper('cross_entropy2', **locals()) out = helper.create_variable_for_type_inference(dtype=input.dtype) xshape = helper.create_variable_for_type_inference(dtype=input.dtype) match_x = helper.create_variable_for_type_inference(dtype=input.dtype) helper.append_op( type='cross_entropy2', inputs={'X': [input], 'Label': [label]}, outputs={'Y': [out], 'MatchX': [match_x], 'XShape': [xshape]}, attrs={'ignore_index': ignore_index}) return out def square_error_cost(input, label): """ This op accepts input predictions and target label and returns the squared error cost. For predictions label, and target label, the equation is: .. math:: Out = (input - label)^2 Parameters: input (Variable): Input tensor, the data type should be float32. label (Variable): Label tensor, the data type should be float32. Returns: The tensor variable storing the element-wise squared error \ difference between input and label. Return type: Variable. Examples: .. code-block:: python # declarative mode import paddle.fluid as fluid import numpy as np input = fluid.data(name="input", shape=[1]) label = fluid.data(name="label", shape=[1]) output = fluid.layers.square_error_cost(input,label) place = fluid.CPUPlace() exe = fluid.Executor(place) exe.run(fluid.default_startup_program()) input_data = np.array([1.5]).astype("float32") label_data = np.array([1.7]).astype("float32") output_data = exe.run(fluid.default_main_program(), feed={"input":input_data, "label":label_data}, fetch_list=[output], return_numpy=True) print(output_data) # [array([0.04000002], dtype=float32)] # imperative mode import paddle.fluid.dygraph as dg with dg.guard(place) as g: input = dg.to_variable(input_data) label = dg.to_variable(label_data) output = fluid.layers.square_error_cost(input, label) print(output.numpy()) # [0.04000002] """ helper = LayerHelper('square_error_cost', **locals()) minus_out = helper.create_variable_for_type_inference(dtype=input.dtype) helper.append_op( type='elementwise_sub', inputs={'X': [input], 'Y': [label]}, outputs={'Out': [minus_out]}) square_out = helper.create_variable_for_type_inference(dtype=input.dtype) helper.append_op( type='square', inputs={'X': [minus_out]}, outputs={'Out': [square_out]}) return square_out def edit_distance(input, label, normalized=True, ignored_tokens=None, input_length=None, label_length=None): """ This op computes the edit distances, also called Levenshtein distance, between a batch of hypothesis strings and their references. It measures how dissimilar two strings are by counting the minimum number of operations to transform one string into another. The operations include insertion, deletion, and substitution. For example, given hypothesis string A = "kitten" and reference B = "sitting", A will be transformed into B at least after two substitutions and one insertion: "kitten" -> "sitten" -> "sittin" -> "sitting" So the edit distance between A and B is 3. The input is a LoDTensor or Tensor. If it is a LoDTensor, The separation is specified by the LoD information. If it is a Tensor, The input_length and label_length should be supported. The `batch_size` of labels should be same as `input`. The output include the edit distance value between every pair of input and related label, and the number of sequence. If Attr(normalized) is true, the edit distance value will be divided by the length of label. Parameters: input(Variable): The input variable which is a tensor or LoDTensor, its rank should be equal to 2 and its data type should be int64. label(Variable): The label variable which is a tensor or LoDTensor, its rank should be equal to 2 and its data type should be int64. normalized(bool, default True): Indicated whether to normalize the edit distance. ignored_tokens(list, default None): Tokens that will be removed before calculating edit distance. input_length(Variable): The length for each sequence in `input` if it's of Tensor type, it should have shape `(batch_size, )` and its data type should be int64. label_length(Variable): The length for each sequence in `label` if it's of Tensor type, it should have shape `(batch_size, )` and its data type should be int64. NOTE: To be avoid unexpected result, the value of every elements in input_length and label_length should be equal to the value of the second dimension of input and label. For example, The input: [[1,2,3,4],[5,6,7,8],[9,10,11,12]], the shape of input is [3,4] and the input_length should be [4,4,4] NOTE: This Api is different from fluid.metrics.EditDistance Returns: Tuple: distance(Variable): edit distance result, its data type is float32, and its shape is (batch_size, 1). sequence_num(Variable): sequence number, its data type is float32, and its shape is (1,). Examples: .. code-block:: python import paddle.fluid as fluid import numpy as np # using LoDTensor x_lod = fluid.data(name='x_lod', shape=[None,1], dtype='int64', lod_level=1) y_lod = fluid.data(name='y_lod', shape=[None,1], dtype='int64', lod_level=1) distance_lod, seq_num_lod = fluid.layers.edit_distance(input=x_lod, label=y_lod) # using Tensor input_data = np.array([[1,2,3],[4,5,6],[4,4,4],[1,1,1]]).astype('int64') label_data = np.array([[1,3,4,1],[4,5,8,1],[7,7,7,1],[1,1,1,1]]).astype('int64') input_len = np.array([3,3,3,3]).astype('int64') label_len = np.array([4,4,4,4]).astype('int64') input_t = fluid.data(name='input', shape=[None,3], dtype='int64') label_t = fluid.data(name='label', shape=[None,4], dtype='int64') input_len_t = fluid.data(name='input_length', shape=[None], dtype='int64') label_len_t = fluid.data(name='label_length', shape=[None], dtype='int64') distance, sequence_num = fluid.layers.edit_distance(input=input_t, label=label_t, input_length=input_len_t, label_length=label_len_t,normalized=False) # print(input_data.shape, label_data.shape) # ((4,3), (4,4)) place = fluid.CPUPlace() exe = fluid.Executor(place) exe.run(fluid.default_startup_program()) dis, seq_num = exe.run(fluid.default_main_program(), feed={"input":input_data, "label":label_data, "input_length": input_len, "label_length": label_len}, fetch_list=[distance,sequence_num]) # print(dis) # [[3.] # [2.] # [4.] # [1.]] # if set normalized to True # [[0.75] # [0.5 ] # [1. ] # [0.25] # # print(seq_num) # [4] """ helper = LayerHelper("edit_distance", **locals()) # remove some tokens from input and labels if ignored_tokens is not None and len(ignored_tokens) > 0: erased_input = helper.create_variable_for_type_inference(dtype="int64") erased_label = helper.create_variable_for_type_inference(dtype="int64") helper.append_op( type="sequence_erase", inputs={"X": [input]}, outputs={"Out": [erased_input]}, attrs={"tokens": ignored_tokens}) input = erased_input helper.append_op( type="sequence_erase", inputs={"X": [label]}, outputs={"Out": [erased_label]}, attrs={"tokens": ignored_tokens}) label = erased_label this_inputs = {"Hyps": [input], "Refs": [label]} if input_length and label_length: this_inputs['HypsLength'] = [input_length] this_inputs['RefsLength'] = [label_length] # edit distance op edit_distance_out = helper.create_variable_for_type_inference(dtype="int64") sequence_num = helper.create_variable_for_type_inference(dtype="int64") helper.append_op( type="edit_distance", inputs=this_inputs, outputs={"Out": [edit_distance_out], "SequenceNum": [sequence_num]}, attrs={"normalized": normalized}) return edit_distance_out, sequence_num def warpctc(input, label, blank=0, norm_by_times=False, input_length=None, label_length=None): """ An operator integrating the open source Warp-CTC library (https://github.com/baidu-research/warp-ctc) to compute Connectionist Temporal Classification (CTC) loss. It can be aliased as softmax with CTC, since a native softmax activation is interated to the Warp-CTC library to normlize values for each row of the input tensor. Args: input (Variable): The unscaled probabilities of variable-length sequences, which is a 2-D Tensor with LoD information, or a 3-D Tensor without Lod information. When it is a 2-D LodTensor, it's shape is [Lp, num_classes + 1], where Lp is the sum of all input sequences' length and num_classes is the true number of classes. (not including the blank label). When it is a 3-D Tensor, it's shape is [max_logit_length, batch_size, num_classes + 1], where max_logit_length is the length of the longest input logit sequence. The data type must be float32. label (Variable): The ground truth of variable-length sequence, which is a 2-D Tensor with LoD information or a 2-D Tensor without LoD information. When it is a 2-D LoDTensor or 2-D Tensor, it is of the shape [Lg, 1], where Lg is th sum of all labels' length. The data type must be int32. blank (int, default 0): The blank label index of Connectionist Temporal Classification (CTC) loss, which is in the half-opened interval [0, num_classes + 1). The data type must be int32. norm_by_times(bool, default false): Whether to normalize the gradients by the number of time-step, which is also the sequence's length. There is no need to normalize the gradients if warpctc layer was follewed by a mean_op. input_length(Variable): The length for each input sequence if it is of Tensor type, it should have shape `[batch_size]` and dtype int64. label_length(Variable): The length for each label sequence if it is of Tensor type, it should have shape `[batch_size]` and dtype int64. Returns: Variable: The Connectionist Temporal Classification (CTC) loss, which is a 2-D Tensor with the shape [batch_size, 1]. The date type is the same as input. Examples: .. code-block:: python # using LoDTensor import paddle.fluid as fluid import numpy as np predict = fluid.data(name='predict', shape=[None, 5], dtype='float32',lod_level=1) label = fluid.data(name='label', shape=[None, 1], dtype='int32', lod_level=1) cost = fluid.layers.warpctc(input=predict, label=label) place = fluid.CPUPlace() x=fluid.LoDTensor() data = np.random.rand(8, 5).astype("float32") x.set(data, place) x.set_lod([[0,4,8]]) y=fluid.LoDTensor() data = np.random.randint(0, 5, [4, 1]).astype("int32") y.set(data, place) y.set_lod([[0,2,4]]) exe = fluid.Executor(place) exe.run(fluid.default_startup_program()) output= exe.run(feed={"predict": x,"label": y}, fetch_list=[cost.name]) print output .. code-block:: python # using Tensor import paddle.fluid as fluid import numpy as np # length of the longest logit sequence max_seq_length = 5 # number of logit sequences batch_size = None logits = fluid.data(name='logits', shape=[max_seq_length, batch_size, 5], dtype='float32') logits_length = fluid.data(name='logits_length', shape=[None], dtype='int64') label = fluid.layers.data(name='label', shape=[None, 1], dtype='int32') label_length = fluid.layers.data(name='labels_length', shape=[None], dtype='int64') cost = fluid.layers.warpctc(input=logits, label=label, input_length=logits_length, label_length=label_length) place = fluid.CPUPlace() batch_size = 2 x = np.random.rand(max_seq_length, batch_size, 5).astype("float32") y = np.random.randint(0, 5, [max_seq_length * batch_size, 1]).astype("int32") exe = fluid.Executor(place) exe.run(fluid.default_startup_program()) output= exe.run(feed={"logits": x, "label": y, "logits_length": np.array([5, 4]).astype("int64"), "labels_length": np.array([3, 2]).astype("int64")}, fetch_list=[cost.name]) print(output) """ helper = LayerHelper('warpctc', **locals()) this_inputs = {'Logits': [input], 'Label': [label]} if input_length and label_length: this_inputs['LogitsLength'] = [input_length] this_inputs['LabelLength'] = [label_length] loss_out = helper.create_variable_for_type_inference(dtype=input.dtype) grad_out = helper.create_variable_for_type_inference(dtype=input.dtype) helper.append_op( type='warpctc', inputs=this_inputs, outputs={'WarpCTCGrad': [grad_out], 'Loss': [loss_out]}, attrs={ 'blank': blank, 'norm_by_times': norm_by_times, }) return loss_out # FIXME(wuyi): let docstring_checker.py understand @autodoc. # For now, the comments in c++ use types like Tensor, but in python side # the type is often "Variable", and arguments may vary. @templatedoc(op_type="nce") def nce(input, label, num_total_classes, sample_weight=None, param_attr=None, bias_attr=None, num_neg_samples=None, name=None, sampler="uniform", custom_dist=None, seed=0, is_sparse=False): """ ${comment} Args: input (Variable): Input variable, 2-D tensor with shape [batch_size, dim], and data type is float32 or float64. label (Variable): Input label, 2-D tensor with shape [batch_size, num_true_class], and data type is int64. num_total_classes (int):${num_total_classes_comment}. sample_weight (Variable|None): A Variable of shape [batch_size, 1] storing a weight for each sample. The default weight for each sample is 1.0. param_attr (ParamAttr|None): To specify the weight parameter attribute. Default: None, which means the default weight parameter property is used. See usage for details in :ref:`api_fluid_ParamAttr` . bias_attr (ParamAttr|None): To specify the bias parameter attribute. Default: None, which means the default bias parameter property is used. See usage for details in :ref:`api_fluid_ParamAttr` . num_neg_samples (int): ${num_neg_samples_comment}. name(str|None): For detailed information, please refer to :ref:`api_guide_Name` . Usually name is no need to set and None by default. sampler (str, optional): The sampler used to sample class from negtive classes. It can be 'uniform', 'log_uniform' or 'custom_dist'. default: 'uniform'. custom_dist (nd.array|None): A numpy ndarray with size=num_total_classes. It is used when sampler is set to 'custom_dist'. custom_dist[i] is the probsbility of i-th class to be sampled. default: None. seed (int, optional): The seed used in sampler. Default 0, means no random seed. is_sparse(bool, optional): The flag indicating whether to use sparse update, the weight@GRAD and bias@GRAD will be changed to SelectedRows. Default False. Returns: Variable: The output nce loss. Examples: .. code-block:: python import paddle.fluid as fluid import numpy as np window_size = 5 words = [] for i in xrange(window_size): words.append(fluid.data( name='word_{0}'.format(i), shape=[-1, 1], dtype='int64')) dict_size = 10000 label_word = int(window_size / 2) + 1 embs = [] for i in xrange(window_size): if i == label_word: continue emb = fluid.layers.embedding(input=words[i], size=[dict_size, 32], param_attr='embed', is_sparse=True) embs.append(emb) embs = fluid.layers.concat(input=embs, axis=1) loss = fluid.layers.nce(input=embs, label=words[label_word], num_total_classes=dict_size, param_attr='nce.w_0', bias_attr='nce.b_0') #or use custom distribution dist = np.array([0.05,0.5,0.1,0.3,0.05]) loss = fluid.layers.nce(input=embs, label=words[label_word], num_total_classes=5, param_attr='nce.w_1', bias_attr='nce.b_1', num_neg_samples=3, sampler="custom_dist", custom_dist=dist) """ helper = LayerHelper('nce', **locals()) check_type_and_dtype(input, 'input', Variable, ['float32', 'float64'], 'nce') check_type_and_dtype(label, 'label', Variable, ['int64'], 'nce') dim = input.shape[1] num_true_class = label.shape[1] w = helper.create_parameter( attr=helper.param_attr, shape=[num_total_classes, dim], is_bias=False, dtype=input.dtype) inputs = {} if helper.bias_attr: b = helper.create_parameter( attr=helper.bias_attr, shape=[num_total_classes, 1], is_bias=True, dtype=input.dtype) inputs['Bias'] = b cost = helper.create_variable_for_type_inference(dtype=input.dtype) sample_logits = helper.create_variable_for_type_inference(dtype=input.dtype) sample_labels = helper.create_variable_for_type_inference(dtype=label.dtype) inputs['Input'] = input inputs['Label'] = label inputs['Weight'] = w inputs['SampleWeight'] = sample_weight if sample_weight is not None else [] if sampler == "uniform": sampler = 0 elif sampler == "log_uniform": sampler = 1 elif sampler == "custom_dist": assert custom_dist is not None custom_dist_len = num_total_classes alias_probs_ = [0] * custom_dist_len alias_ = [0] * custom_dist_len bigs = [] littles = [] for i in range(custom_dist_len): normal_prob = custom_dist[i] * custom_dist_len if normal_prob - 1.0 > 0: bigs.append((i, normal_prob)) elif 1.0 - normal_prob > 0: littles.append((i, normal_prob)) else: alias_probs_[i] = normal_prob alias_[i] = -1 while len(bigs) and len(littles): big = bigs.pop(0) little = littles.pop(0) big_idx = big[0] big_prob = big[1] alias_probs_[little[0]] = little[1] alias_[little[0]] = big_idx big_left = big[1] + little[1] - 1 if big_left - 1.0 > 0: bigs.append((big_idx, big_left)) elif 1.0 - big_left > 0: littles.append((big_idx, big_left)) else: alias_probs_[big_idx] = big_left alias_[big_idx] = -1 if len(bigs): big = bigs.pop(0) alias_probs_[big[0]] = 1.0 alias_[big[0]] = -1 if len(littles): little = littles.pop(0) alias_probs_[little[0]] = 1.0 alias_[little[0]] = -1 def _init_by_numpy_array(numpy_array): ret = helper.create_parameter( attr=ParamAttr(), shape=numpy_array.shape, dtype=numpy_array.dtype, default_initializer=NumpyArrayInitializer(numpy_array)) ret.stop_gradient = True return ret inputs['CustomDistProbs'] = _init_by_numpy_array( np.array(custom_dist).astype('float32')) inputs['CustomDistAlias'] = _init_by_numpy_array( np.array(alias_).astype('int32')) inputs['CustomDistAliasProbs'] = _init_by_numpy_array( np.array(alias_probs_).astype('float32')) sampler = 2 else: raise Exception("Unsupported sampler type.") if num_neg_samples is None: num_neg_samples = 10 else: num_neg_samples = int(num_neg_samples) remote_prefetch = is_sparse print( "With sparse mode, if your models has only small parameter prefetch may cause speed down" ) attrs = { 'num_total_classes': int(num_total_classes), 'num_neg_samples': num_neg_samples, 'seed': seed, 'sampler': sampler, 'is_sparse': is_sparse, 'remote_prefetch': remote_prefetch } helper.append_op( type='nce', inputs=inputs, outputs={ 'Cost': cost, 'SampleLogits': sample_logits, 'SampleLabels': sample_labels }, attrs=attrs) return cost / (num_neg_samples + 1) def hsigmoid(input, label, num_classes, param_attr=None, bias_attr=None, name=None, path_table=None, path_code=None, is_custom=False, is_sparse=False): """ The hierarchical sigmoid organizes the classes into a complete binary tree to reduce the computational complexity and speed up the model training, especially the training of language model. Each leaf node of the complete binary tree represents a class(word) and each non-leaf node acts as a binary classifier. For each class(word), there's a unique path from root to itself, hsigmoid calculate the cost for each non-leaf node on the path, and sum them to get a total cost. Comparing to softmax, the OP can reduce the computational complexity from :math:`O(N)` to :math:`O(logN)`, where :math:`N` represents the number of classes or the size of word dict. The OP supports default tree and custom tree. For the default tree, you can refer to `Hierarchical Probabilistic Neural Network Language Model `. For the custom tree, you need to set :attr:`is_custom` to True, and do the following steps (take the language model as an example): 1. Using a custom word dict to build a binary tree, each leaf node should be an word in the word dict. 2. Creating a dict map word_id -> path that from the word to the root node, we call it path_table. 3. Creating a dict map word_id -> code of path that from the word to the root node, we call it path_code. Code means the label of each binary classifier, 1 indicate true, 0 indicate false. 4. Now, each word should has its path and code along the path, you can pass a batch of path and code related to the same batch of inputs. Parameters: input (Variable): A tensor with the shape [N, D], where N is the size of mini-batch, and D is the feature size. Its data type supports float32 and float64. label (Variable): A tensor contains the labels of training data. Its shape is [N, 1] and data type is int64. num_classes (int): The number of classes or the size of word dict, must be greater than 2. If the default tree is used (:attr:`is_custom` is set to False), :attr:`num_classes` should not be None. If the custom tree is used (:attr:`is_custom` is set to True), :attr:`num_classes` should be the number of non-leaf nodes, which indicates the num of classes using by the binary classifier. param_attr (ParamAttr, optional): The parameter attribute for the learnable parameters/weights of hsigmoid. If it is set to None or one attribute of ParamAttr, hsigmoid will create a ParamAttr as param_attr. If the Initializer of the param_attr is not set, the parameter is initialized with Xavier. Default: None. bias_attr (ParamAttr|bool, optional): The parameter attribute for the bias of hsigmoid. If it is set to False, no bias will be added. If it is set to None or one attribute of ParamAttr, hsigmoid will create a ParamAttr as bias_attr. If the Initializer of the bias_attr is not set, the bias is initialized zero. Default: None. name (str, optional): Normally there is no need for user to set this property. For more information, please refer to :ref:`api_guide_Name`. Default: None. path_table (Variable, optional): A tensor that stores each batch of samples' path from leaf to root node, its shape is [N, L] and data type is int64, where L is the length of path. For each sample i, path_table[i] is a np.array like structure and each element in this array is the indexes in parent nodes' weight matrix. Default: None. path_code (Variable, optional): A tensor that stores each batch of samples' code of path from leaf to root node, its shape is [N, L] and data type is int64, which is the same as :attr:`path_table`. Each code of path is consisted with the code of nodes from leaf to root node. Default: None. is_custom (bool, optional): Whether use custom binary tree. If it's True, :attr:`path_table`, :attr:`path_code` and :attr:`num_classes` should be set, otherwise :attr:`num_classes` should be set. Default: False. is_sparse (bool, optional): Whether use sparse updating instead of dense updating, if it's True, the gradient of W and input will be sparse. Default: False. Returns: Variable: A tensor with the cost of hierarchical sigmoid, its shape is [N, 1] and data type is the same as :attr:`input`. Examples: .. code-block:: python import paddle.fluid as fluid x = fluid.layers.fill_constant(shape=[4, 3], value=0.9, dtype='float32') # x = [[0.9, 0.9, 0.9], [0.9, 0.9, 0.9], [0.9, 0.9, 0.9], [0.9, 0.9, 0.9]] y = fluid.layers.fill_constant( shape=[4, 1], value=1, dtype='int64') # y = [[1], [1], [1], [1]] out = fluid.layers.hsigmoid(input=x, label=y, num_classes=2, param_attr=fluid.initializer.Constant( value=0.05), bias_attr=fluid.initializer.Constant(value=.0)) # out = [[0.62792355], [0.62792355], [0.62792355], [0.62792355]] """ helper = LayerHelper('hierarchical_sigmoid', **locals()) dtype = helper.input_dtype() out = helper.create_variable_for_type_inference(dtype) pre_out = helper.create_variable_for_type_inference(dtype) dim = input.shape[1] if ((num_classes is None) or (num_classes < 2)) and (not is_custom): raise ValueError( "num_classes must not be less than 2 with default tree") if (not is_custom) and (is_sparse): print("Sparse mode should not be used without custom tree") is_sparse = False if (not is_custom) and ((path_table is not None) or (path_code is not None)): raise ValueError( "only num_classes should be passed without custom tree") if (is_custom) and (path_code is None): raise ValueError("path_code should not be None with custom tree") elif (is_custom) and (path_table is None): raise ValueError("path_table should not be None with custom tree") elif (is_custom) and (num_classes is None): raise ValueError("num_classes should not be None with custom tree") else: pass weights = None remote_prefetch = is_sparse print( "With sparse mode, if your models has only small parameter prefetch may cause speed down" ) if not is_custom: weights = helper.create_parameter( attr=helper.param_attr, shape=[num_classes - 1, dim], is_bias=False, dtype=input.dtype) else: weights = helper.create_parameter( attr=helper.param_attr, shape=[num_classes, dim], is_bias=False, dtype=input.dtype) inputs = { "X": input, "W": weights, "PathTable": path_table, "PathCode": path_code, "Label": label } if helper.bias_attr: if not is_custom: bias = helper.create_parameter( attr=helper.bias_attr, shape=[num_classes - 1, 1], is_bias=True, dtype=input.dtype) inputs['Bias'] = bias else: bias = helper.create_parameter( attr=helper.bias_attr, shape=[num_classes, 1], is_bias=True, dtype=input.dtype) inputs['Bias'] = bias helper.append_op( type="hierarchical_sigmoid", inputs=inputs, outputs={"Out": out, "PreOut": pre_out, "W_Out": weights}, attrs={ "num_classes": num_classes, "is_sparse": is_sparse, "remote_prefetch": remote_prefetch }) return out def sampled_softmax_with_cross_entropy(logits, label, num_samples, num_true=1, remove_accidental_hits=True, use_customized_samples=False, customized_samples=None, customized_probabilities=None, seed=0): """ **Sampled Softmax With Cross Entropy Operator.** Cross entropy loss with sampled softmax is used as the output layer for larger output classes extensively. This operator samples a number of samples for all examples, and computes the softmax normalized values for each row of the sampled tensor, after which cross-entropy loss is computed. Because this operator performs a softmax on logits internally, it expects unscaled logits. This operator should not be used with the output of softmax operator since that would produce incorrect results. For examples with T true labels (T >= 1), we assume that each true label has a probability of 1/T. For each sample, S samples are generated using a log uniform distribution. True labels are concatenated with these samples to form T + S samples for each example. So, assume the shape of logits is [N x K], the shape for samples is [N x (T+S)]. For each sampled label, a probability is calculated, which corresponds to the Q(y|x) in [Jean et al., 2014](http://arxiv.org/abs/1412.2007). Logits are sampled according to the sampled labels. Then if remove_accidental_hits is True, if a sample[i, j] accidentally hits true labels, then the corresponding sampled_logits[i, j] is minus by 1e20 to make its softmax result close to zero. Then sampled logits are subtracted by logQ(y|x), these sampled logits and re-indexed labels are used to compute a softmax with cross entropy. Args: logits (Variable): The unscaled log probabilities, which is a 2-D tensor with shape [N x K]. N is the batch_size, and K is the class number. label (Variable): The ground truth which is a 2-D tensor. Label is a Tensor with shape [N x T], where T is the number of true labels per example. num_samples (int): The number for each example, num_samples should be less than the number of class. num_true(int): The number of target classes per training example. remove_accidental_hits (bool): A flag indicating whether to remove accidental hits when sampling. If True and if a sample[i, j] accidentally hits true labels, then the corresponding sampled_logits[i, j] is minus by 1e20 to make its softmax result close to zero. Default is True. use_customized_samples (bool): Whether to use custom samples and probabities to sample logits. customized_samples (Variable): User defined samples, which is a 2-D tensor with shape [N, T + S]. S is the num_samples, and T is the number of true labels per example. customized_probabilities (Variable): User defined probabilities of samples, a 2-D tensor which has the same shape with customized_samples. seed (int): The random seed for generating random number, which is used in the process of sampling. Default is 0. Returns: Variable: Return the cross entropy loss which is a 2-D tensor with shape [N x 1]. Examples: .. code-block:: python import paddle.fluid as fluid input = fluid.layers.data(name='data', shape=[256], dtype='float32') label = fluid.layers.data(name='label', shape=[1], dtype='int64') fc = fluid.layers.fc(input=input, size=100) out = fluid.layers.sampled_softmax_with_cross_entropy( logits=fc, label=label, num_samples=25) """ helper = LayerHelper('sample_logits', **locals()) samples = customized_samples if use_customized_samples else helper.create_variable_for_type_inference( dtype='int64') probabilities = customized_probabilities if use_customized_samples else helper.create_variable_for_type_inference( dtype=logits.dtype) sampled_logits \ = helper.create_variable_for_type_inference(dtype=logits.dtype) sampled_label = helper.create_variable_for_type_inference(dtype='int64') sampled_softlabel = helper.create_variable_for_type_inference( dtype=logits.dtype) logits_dim = helper.create_variable_for_type_inference(dtype=logits.dtype) labels_dim = helper.create_variable_for_type_inference(dtype=label.type) helper.append_op( type='sample_logits', inputs={ 'Logits': logits, 'Labels': label, 'CustomizedSamples': customized_samples, 'CustomizedProbabilities': customized_probabilities }, outputs={ 'Samples': samples, 'Probabilities': probabilities, 'SampledLabels': sampled_label, 'SampledLogits': sampled_logits, 'LogitsDim': logits_dim, 'LabelsDim': labels_dim }, attrs={ 'use_customized_samples': use_customized_samples, 'uniq': True, 'remove_accidental_hits': remove_accidental_hits, 'num_samples': num_samples, 'seed': seed }) loss = helper.create_variable_for_type_inference(dtype=logits.dtype) softmax = helper.create_variable_for_type_inference(dtype=logits.dtype) helper.append_op( type='one_hot', inputs={'X': sampled_label}, attrs={'depth': num_samples + 1}, outputs={'Out': sampled_softlabel}) helper.append_op( type='softmax_with_cross_entropy', inputs={'Logits': sampled_logits, 'Label': sampled_softlabel}, outputs={'Softmax': softmax, 'Loss': loss}, attrs={ 'soft_label': True, 'ignore_index': False, 'numeric_stable_mode': False }) return loss / num_true def softmax_with_cross_entropy(logits, label, soft_label=False, ignore_index=kIgnoreIndex, numeric_stable_mode=True, return_softmax=False, axis=-1): """ This operator implements the cross entropy loss function with softmax. This function combines the calculation of the softmax operation and the cross entropy loss function to provide a more numerically stable gradient. Because this operator performs a softmax on logits internally, it expects unscaled logits. This operator should not be used with the output of softmax operator since that would produce incorrect results. When the attribute :attr:`soft_label` is set :attr:`False`, this operators expects mutually exclusive hard labels, each sample in a batch is in exactly one class with a probability of 1.0. Each sample in the batch will have a single label. The equation is as follows: 1) Hard label (one-hot label, so every sample has exactly one class) .. math:: loss_j = -\\text{logits}_{label_j} + \\log\\left(\\sum_{i=0}^{K}\\exp(\\text{logits}_i)\\right), j = 1,..., K 2) Soft label (each sample can have a distribution over all classes) .. math:: loss_j = -\\sum_{i=0}^{K}\\text{label}_i \\left(\\text{logits}_i - \\log\\left(\\sum_{i=0}^{K} \\exp(\\text{logits}_i)\\right)\\right), j = 1,...,K 3) If :attr:`numeric_stable_mode` is :attr:`True`, softmax is calculated first by: .. math:: max_j &= \\max_{i=0}^{K}{\\text{logits}_i} log\\_max\\_sum_j &= \\log\\sum_{i=0}^{K}\\exp(logits_i - max_j) softmax_j &= \\exp(logits_j - max_j - {log\\_max\\_sum}_j) and then cross entropy loss is calculated by softmax and label. Args: logits (Variable): A multi-dimension ``Tensor`` , and the data type is float32 or float64. The input tensor of unscaled log probabilities. label (Variable): The ground truth ``Tensor`` , data type is the same as the ``logits`` . If :attr:`soft_label` is set to :attr:`True`, Label is a ``Tensor`` in the same shape with :attr:`logits`. If :attr:`soft_label` is set to :attr:`True`, Label is a ``Tensor`` in the same shape with :attr:`logits` expect shape in dimension :attr:`axis` as 1. soft_label (bool, optional): A flag to indicate whether to interpretate the given labels as soft labels. Default False. ignore_index (int, optional): Specifies a target value that is ignored and does not contribute to the input gradient. Only valid if :attr:`soft_label` is set to :attr:`False`. Default: kIgnoreIndex(-100). numeric_stable_mode (bool, optional): A flag to indicate whether to use a more numerically stable algorithm. Only valid when :attr:`soft_label` is :attr:`False` and GPU is used. When :attr:`soft_label` is :attr:`True` or CPU is used, the algorithm is always numerically stable. Note that the speed may be slower when use stable algorithm. Default: True. return_softmax (bool, optional): A flag indicating whether to return the softmax along with the cross entropy loss. Default: False. 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 :attr:`logits`. Default: -1. Returns: ``Variable`` or Tuple of two ``Variable`` : Return the cross entropy loss if \ `return_softmax` is False, otherwise the tuple \ (loss, softmax), softmax is in the same shape \ with input logits and cross entropy loss is in \ the same shape with input logits except shape \ in dimension :attr:`axis` as 1. Examples: .. code-block:: python import paddle.fluid as fluid data = fluid.data(name='data', shape=[-1, 128], dtype='float32') label = fluid.data(name='label', shape=[-1, 1], dtype='int64') fc = fluid.layers.fc(input=data, size=100) out = fluid.layers.softmax_with_cross_entropy( logits=fc, label=label) """ helper = LayerHelper('softmax_with_cross_entropy', **locals()) softmax = helper.create_variable_for_type_inference(dtype=logits.dtype) loss = helper.create_variable_for_type_inference(dtype=logits.dtype) helper.append_op( type='softmax_with_cross_entropy', inputs={'Logits': logits, 'Label': label}, outputs={'Softmax': softmax, 'Loss': loss}, attrs={ 'soft_label': soft_label, 'ignore_index': ignore_index, 'numeric_stable_mode': numeric_stable_mode, 'axis': axis }) if return_softmax: return loss, softmax return loss def rank_loss(label, left, right, name=None): """ This operator implements the sort loss layer in the RankNet model. RankNet is a pairwise ranking model with a training sample consisting of a pair of documents (A and B), The label (P) indicates whether A is ranked higher than B or not. Please refer to more details: `RankNet `_ Rank loss layer takes three inputs: left ( :math:`o_i` ), right ( :math:`o_j` ) and label ( :math:`P_{i,j}` ). The inputs respectively represent RankNet's output scores for documents A and B and the value of label P. Rank loss layer takes batch inputs with size batch_size (batch_size >= 1), P = {0, 1} or {0, 0.5, 1}, where 0.5 means that there is no information about the rank of the input pair. The following equation computes rank loss C_{i,j} from the inputs: .. math:: C_{i,j} &= -\\tilde{P_{ij}} * o_{i,j} + \log(1 + e^{o_{i,j}}) \\\\ .. math:: o_{i,j} &= o_i - o_j \\\\ .. math:: \\tilde{P_{i,j}} &= \\left \{0, 0.5, 1 \\right \} \ or \ \\left \{0, 1 \\right \} Parameters: label (Variable): 2-D ``Tensor`` with the shape of :math:`[batch,1]`, the data type is float32, batch indicates the size of the data. Indicats whether A ranked higher than B or not. left (Variable): 2-D ``Tensor`` with the shape of :math:`[batch,1]`, the data type is float32. RankNet's output score for doc A. right (Variable): 2-D ``Tensor`` with the shape of :math:`[batch,1]`, the data type is float32. RankNet's output score for doc B. name(str|None): 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`` indicating the output value of the sort loss layer, the data type is float32, and the return value's shape is :math:`[batch,1]` . Raises: ValueError: Any of label, left, and right is not a ``Variable`` . Examples: .. code-block:: python import paddle.fluid as fluid label = fluid.data(name="label", shape=[-1, 1], dtype="float32") left = fluid.data(name="left", shape=[-1, 1], dtype="float32") right = fluid.data(name="right", shape=[-1, 1], dtype="float32") out = fluid.layers.rank_loss(label, left, right) """ helper = LayerHelper('rank_loss', **locals()) if not (isinstance(label, Variable)): raise ValueError("The label should be a Variable") if not (isinstance(left, Variable)): raise ValueError("The left should be a Variable") if not (isinstance(right, Variable)): raise ValueError("The right should be a Variable") out = helper.create_variable_for_type_inference("float32") helper.append_op( type='rank_loss', inputs={"Label": label, "Left": left, "Right": right}, outputs={'Out': out}) return out def margin_rank_loss(label, left, right, margin=0.1, name=None): """ Margin Ranking Loss Layer for ranking problem, which compares left score and right score passed in. The ranking loss can be defined as following equation: .. math:: rank\_loss = max(0, -label * (left - right) + margin) Args: label (Variable): Indicates whether the left is ranked higher than the right or not. Data type is float32. left (Variable): Ranking score for left. Data type float32. right (Variable): Ranking score for right. Data type float32. margin (float): Indicates the given margin. name(str|None): For detailed information, please refer to :ref:`api_guide_Name` . Usually name is no need to set and None by default. Returns: Variable: The ranking loss. Raises: ValueError: Any of label, left, and right is not a Variable. Examples: .. code-block:: python import paddle.fluid as fluid label = fluid.data(name="label", shape=[-1, 1], dtype="float32") left = fluid.data(name="left", shape=[-1, 1], dtype="float32") right = fluid.data(name="right", shape=[-1, 1], dtype="float32") out = fluid.layers.margin_rank_loss(label, left, right) """ helper = LayerHelper('margin_rank_loss', **locals()) if not isinstance(label, Variable): raise ValueError("The label should be a Variable.") if not isinstance(left, Variable): raise ValueError("The left should be a Variable.") if not isinstance(right, Variable): raise ValueError("The right should be a Variable.") out = helper.create_variable_for_type_inference(left.dtype) act = helper.create_variable_for_type_inference(left.dtype) helper.append_op( type='margin_rank_loss', inputs={"Label": label, "X1": left, "X2": right}, outputs={'Out': out, 'Activated': act}, attrs={'margin': margin}) return out @templatedoc() def sigmoid_cross_entropy_with_logits(x, label, ignore_index=kIgnoreIndex, name=None, normalize=False): """ ${comment} Args: x(${x_type}): ${x_comment} label(${label_type}): ${label_comment} ignore_index(int): ${ignore_index_comment} name(str|None): The default value is None. Normally there is no need for user to set this property. For more information, please refer to :ref:`api_guide_Name` normalize(bool): If true, divide the output by the number of targets != ignore_index. Returns: out(${out_type}): ${out_comment} Examples: .. code-block:: python import paddle.fluid as fluid input = fluid.data( name='data', shape=[10], dtype='float32') label = fluid.data( name='data', shape=[10], dtype='float32') loss = fluid.layers.sigmoid_cross_entropy_with_logits( x=input, label=label, ignore_index=-1, normalize=True) # or False # loss = fluid.layers.reduce_sum(loss) # summation of loss """ helper = LayerHelper("sigmoid_cross_entropy_with_logits", **locals()) if name is None: out = helper.create_variable_for_type_inference(dtype=x.dtype) else: out = helper.create_variable( name=name, dtype=x.dtype, persistable=False) helper.append_op( type="sigmoid_cross_entropy_with_logits", inputs={"X": x, "Label": label}, attrs={"ignore_index": ignore_index, 'normalize': normalize}, outputs={"Out": out}) return out def teacher_student_sigmoid_loss(input, label, soft_max_up_bound=15.0, soft_max_lower_bound=-15.0): """ **Teacher Student Log Loss Layer** This layer accepts input predictions and target label and returns the teacher_student loss. Z is click or not, z' is value of teacher loss, label = {-2, -1, [0, 2]} when z' is not exist, clk = 0 : label = -2; when z' is not exist, clk = 1 : label = -1; when z' is exist , clk = 0 : label = 0 + z'; when z' is exist , clk = 1 : label = 1 + z' .. math:: loss = max(x, 0) - x * z + log(1 + exp(-abs(x))) + max(x, 0) - x * z' + log(1 + exp(-abs(x))) Args: input (Variable|list): a 2-D tensor with shape [N x 1], where N is the batch size. This input is a probability computed by the previous operator. label (Variable|list): the ground truth which is a 2-D tensor with shape [N x 1], where N is the batch size. soft_max_up_bound (float): if input > soft_max_up_bound, will be bound soft_max_lower_bound (float): if input < soft_max_lower_bound, will be bound Returns: Variable: A 2-D tensor with shape [N x 1], the teacher_student_sigmoid_loss. Examples: .. code-block:: python import paddle.fluid as fluid batch_size = 64 label = fluid.data( name="label", shape=[batch_size, 1], dtype="int64") similarity = fluid.data( name="similarity", shape=[batch_size, 1], dtype="float32") cost = fluid.layers.teacher_student_sigmoid_loss(input=similarity, label=label) """ helper = LayerHelper('teacher_student_sigmoid_loss', **locals()) out = helper.create_variable(dtype=input.dtype) helper.append_op( type='teacher_student_sigmoid_loss', inputs={'X': [input], 'Label': [label]}, outputs={'Y': [out]}, attrs={"soft_max_lower_bound": float(soft_max_lower_bound), \ "soft_max_up_bound": float(soft_max_up_bound)}) return out def huber_loss(input, label, delta): """ This operator computes the Huber loss between input and label. Huber loss is commonly used in regression tasks. Compared to square_error_cost, Huber loss is more robust and less sensitivity to outliers. When the absolute difference between input and label is greater than delta, the linear error is calculated: .. math:: huber\_loss = delta * (label - input) - 0.5 * delta * delta When the absolute difference between input and label is greater than delta, the square error is calculated: .. math:: huber\_loss = 0.5 * (label - input) * (label - input) Args: input (Variable): Predicted data, 2D-Tensor with the shape of [batch_size, 1]. The data type should be float32 or float64. label (Variable): Ground truth label, 2D-Tensor with the shape of [batch_size, 1]. The data type should be float32 or float64. delta (float): The threshold for Huber loss, which is used to control the balance between the linear error and square error. The data type should be float32. Returns: Variable: The huber loss, a tensor with the same shape and data type as input. Examples: .. code-block:: python import paddle.fluid as fluid import numpy as np DATATYPE='float32' input_data = np.array([[1.],[2.],[3.],[4.]]).astype(DATATYPE) label_data = np.array([[3.],[3.],[4.],[4.]]).astype(DATATYPE) x = fluid.data(name='input', shape=[None, 1], dtype=DATATYPE) y = fluid.data(name='label', shape=[None, 1], dtype=DATATYPE) loss = fluid.layers.huber_loss(input=x, label=y, delta=1.0) place = fluid.CPUPlace() #place = fluid.CUDAPlace(0) exe = fluid.Executor(place) HuberLoss, = exe.run(feed={'input':input_data ,'label':label_data}, fetch_list=[loss.name]) print(HuberLoss) #[[1.5], [0.5], [0.5], [0. ]], dtype=float32 """ helper = LayerHelper('huber_loss', **locals()) residual = helper.create_variable_for_type_inference( dtype=helper.input_dtype()) out = helper.create_variable_for_type_inference(dtype=helper.input_dtype()) helper.append_op( type='huber_loss', inputs={'X': input, 'Y': label}, outputs={'Out': out, 'Residual': residual}, attrs={'delta': delta}) return out @templatedoc() def kldiv_loss(x, target, reduction='mean', name=None): """ ${comment} Args: x (Variable): ${x_comment} target (Variable): ${target_comment} reduction (Variable): ${reduction_comment} name(str, optional): For detailed information, please refer to :ref:`api_guide_Name`. Usually name is no need to set and None by default. Returns: Variable(Tensor): The KL divergence loss. The data type is same as input tensor Examples: .. code-block:: python import paddle.fluid as fluid x = fluid.data(name='x', shape=[None,4,2,2], dtype='float32') target = fluid.layers.data(name='target', shape=[4,2,2], dtype='float32') loss = fluid.layers.kldiv_loss(x=x, target=target, reduction='batchmean') """ helper = LayerHelper('kldiv_loss', **locals()) loss = helper.create_variable_for_type_inference(dtype=x.dtype) helper.append_op( type='kldiv_loss', inputs={'X': x, 'Target': target}, outputs={'Loss': loss}, attrs={'reduction': reduction}) return loss from .ops import square from .control_flow import equal def npair_loss(anchor, positive, labels, l2_reg=0.002): ''' **Npair Loss Layer** Read `Improved Deep Metric Learning with Multi class N pair Loss Objective\ `_ . Npair loss requires paired data. Npair loss has two parts: the first part is L2 regularizer on the embedding vector; the second part is cross entropy loss which takes the similarity matrix of anchor and positive as logits. Args: anchor(Variable): embedding vector for the anchor image. shape=[batch_size, embedding_dims], the data type is float32 or float64. positive(Variable): embedding vector for the positive image. shape=[batch_size, embedding_dims], the data type is float32 or float64. labels(Variable): 1-D tensor. shape=[batch_size], the data type is float32 or float64 or int64. l2_reg(float32): L2 regularization term on embedding vector, default: 0.002. Returns: A Variable holding Tensor representing the npair loss, the data type is the same as anchor, the shape is [1]. Examples: .. code-block:: python import paddle.fluid as fluid anchor = fluid.data( name = 'anchor', shape = [18, 6], dtype = 'float32') positive = fluid.data( name = 'positive', shape = [18, 6], dtype = 'float32') labels = fluid.data( name = 'labels', shape = [18], dtype = 'float32') npair_loss = fluid.layers.npair_loss(anchor, positive, labels, l2_reg = 0.002) ''' Beta = 0.25 batch_size = labels.shape[0] labels = nn.reshape(labels, shape=[batch_size, 1], inplace=True) labels = nn.expand(labels, expand_times=[1, batch_size]) labels = equal(labels, nn.transpose(labels, perm=[1, 0])).astype('float32') labels = labels / nn.reduce_sum(labels, dim=1, keep_dim=True) l2loss = nn.reduce_mean(nn.reduce_sum(square(anchor), 1)) \ + nn.reduce_mean(nn.reduce_sum(square(positive), 1)) l2loss = l2loss * Beta * l2_reg similarity_matrix = nn.matmul( anchor, positive, transpose_x=False, transpose_y=True) softmax_ce = softmax_with_cross_entropy( logits=similarity_matrix, label=labels, soft_label=True) cross_entropy = nn.reduce_sum(labels * softmax_ce, 0) celoss = nn.reduce_mean(cross_entropy) return l2loss + celoss def mse_loss(input, label): """ This op accepts input predications and target label and returns the mean square error. The loss can be described as: .. math:: Out = MEAN((input - label)^2) Parameters: input (Variable): Input tensor, the data type should be float32. label (Variable): Label tensor, the data type shoulf be float32. Returns: Variable: The tensor variable storing the mean square error difference of input and label. Return type: Variable. Examples: .. code-block:: python # declarative mode import paddle.fluid as fluid import numpy as np input = fluid.data(name="input", shape=[1]) label = fluid.data(name="label", shape=[1]) output = fluid.layers.mse_loss(input,label) place = fluid.CPUPlace() exe = fluid.Executor(place) exe.run(fluid.default_startup_program()) input_data = np.array([1.5]).astype("float32") label_data = np.array([1.7]).astype("float32") output_data = exe.run(fluid.default_main_program(), feed={"input":input_data, "label":label_data}, fetch_list=[output], return_numpy=True) print(output_data) # [array([0.04000002], dtype=float32)] # imperative mode import paddle.fluid.dygraph as dg with dg.guard(place) as g: input = dg.to_variable(input_data) label = dg.to_variable(label_data) output = fluid.layers.mse_loss(input, label) print(output.numpy()) # [0.04000002] """ return nn.reduce_mean(square_error_cost(input, label))