""" All layers just related to the neural network. """ from ..layer_helper import LayerHelper from ..initializer import Normal, Constant from ..framework import Variable from ..param_attr import ParamAttr from tensor import concat __all__ = [ 'fc', 'embedding', 'dynamic_lstm', 'gru_unit', 'linear_chain_crf', 'crf_decoding', 'cos_sim', 'cross_entropy', 'square_error_cost', 'accuracy', 'chunk_eval', 'sequence_conv', 'conv2d', 'sequence_pool', 'pool2d', 'batch_norm', 'beam_search_decode', 'conv2d_transpose', 'sequence_expand', 'lstm_unit', 'reduce_sum', 'sequence_first_step', 'sequence_last_step' ] def fc(input, size, num_flatten_dims=1, param_attr=None, bias_attr=None, act=None, name=None): """ Fully Connected Layer. Args: input: The input tensor to the function size: The size of the layer num_flatten_dims: Number of columns in input param_attr: The parameters/weights to the FC Layer param_initializer: Initializer used for the weight/parameter. If None, XavierInitializer() is used bias_attr: The bias parameter for the FC layer bias_initializer: Initializer used for the bias. If None, then ConstantInitializer() is used act: Activation to be applied to the output of FC layer name: Name/alias of the function main_program: Name of the main program that calls this startup_program: Name of the startup program This function can take in multiple inputs and performs the Fully Connected function (linear transformation) on top of each of them. So for input x, the output will be : Wx + b. Where W is the parameter, b the bias and x is the input. The function also applies an activation (non-linearity) on top of the output, if activation is passed in the input. All the input variables of this function are passed in as local variables to the LayerHelper constructor. """ helper = LayerHelper('fc', **locals()) dtype = helper.input_dtype() mul_results = [] for input_var, param_attr in helper.iter_inputs_and_params(): input_shape = input_var.shape param_shape = [ reduce(lambda a, b: a * b, input_shape[num_flatten_dims:], 1) ] + [size] w = helper.create_parameter( attr=param_attr, shape=param_shape, dtype=dtype, is_bias=False) tmp = helper.create_tmp_variable(dtype) helper.append_op( type="mul", inputs={ "X": input_var, "Y": w, }, outputs={"Out": tmp}, attrs={'x_num_col_dims': num_flatten_dims, 'y_num_col_dims': 1}) mul_results.append(tmp) # sum if len(mul_results) == 1: pre_bias = mul_results[0] else: pre_bias = helper.create_tmp_variable(dtype) helper.append_op( type="sum", inputs={"X": mul_results}, outputs={"Out": pre_bias}) # add bias pre_activation = helper.append_bias_op(pre_bias) # add activation return helper.append_activation(pre_activation) def embedding(input, size, is_sparse=False, param_attr=None, dtype='float32'): """ Embedding Layer. Args: param_initializer: input: The input to the function size: The size of the layer is_sparse: A flag that decleares whether the input is sparse param_attr: Parameters for this layer dtype: The type of data : float32, float_16, int etc main_program: Name of the main program that calls this startup_program: Name of the startup program This function can take in the input (which is a vector of IDs) and performs a lookup in the lookup_table using these IDs, to result into the embedding of each ID in the input. All the input variables of this function are passed in as local variables to the LayerHelper constructor. """ helper = LayerHelper('embedding', **locals()) w = helper.create_parameter( attr=helper.param_attr, shape=size, dtype=dtype, is_bias=False) tmp = helper.create_tmp_variable(dtype) helper.append_op( type='lookup_table', inputs={'Ids': input, 'W': w}, outputs={'Out': tmp}, attrs={'is_sparse': is_sparse}) return tmp # TODO(qijun): expose H0 and C0 def dynamic_lstm(input, size, param_attr=None, bias_attr=None, use_peepholes=True, is_reverse=False, gate_activation='sigmoid', cell_activation='tanh', candidate_activation='tanh', dtype='float32'): helper = LayerHelper('lstm', **locals()) size = size / 4 weight = helper.create_parameter( attr=helper.param_attr, shape=[size, 4 * size], dtype=dtype) bias_size = [1, 7 * size] if not use_peepholes: bias_size[1] = 4 * size bias = helper.create_parameter( attr=helper.bias_attr, shape=bias_size, dtype=dtype, is_bias=True) hidden = helper.create_tmp_variable(dtype) cell = helper.create_tmp_variable(dtype) batch_gate = helper.create_tmp_variable(dtype) batch_cell_pre_act = helper.create_tmp_variable(dtype) helper.append_op( type='lstm', inputs={'Input': input, 'Weight': weight, 'Bias': bias}, outputs={ 'Hidden': hidden, 'Cell': cell, 'BatchGate': batch_gate, 'BatchCellPreAct': batch_cell_pre_act }, attrs={ 'use_peepholes': use_peepholes, 'is_reverse': is_reverse, 'gate_activation': gate_activation, 'cell_activation': cell_activation, 'candidate_activation': candidate_activation }) return hidden, cell def gru_unit(input, hidden, size, weight=None, bias=None, activation='tanh', gate_activation='sigmoid'): """ GRUUnit Operator implements partial calculations of the GRU unit as following: $$ update \ gate: u_t = actGate(xu_t + W_u * h_{t-1} + b_u) \\ reset \ gate: r_t = actGate(xr_t + W_r * h_{t-1} + b_r) \\ output \ candidate: {h}_t = actNode(xc_t + W_c * dot(r_t, h_{t-1}) + b_c) \\ output: h_t = dot((1 - u_t), h_{t-1}) + dot(u_t, {h}_t) $$ which is same as one time step of GRU Operator. @note To implement the complete GRU unit, fully-connected operator must be used before to feed xu, xr and xc as the Input of GRUUnit operator. TODO(ChunweiYan) add more document here """ activation_dict = dict( identity=0, sigmoid=1, tanh=2, relu=3, ) activation = activation_dict[activation] gate_activation = activation_dict[gate_activation] helper = LayerHelper('gru_unit', **locals()) dtype = helper.input_dtype() size = size / 3 # create weight if weight is None: weight = helper.create_parameter( attr=helper.param_attr, shape=[size, 3 * size], dtype=dtype) # create bias if bias is None: bias_size = [1, 3 * size] bias = helper.create_parameter( attr=helper.bias_attr, shape=bias_size, dtype=dtype, is_bias=True) gate = helper.create_tmp_variable(dtype) reset_hidden_pre = helper.create_tmp_variable(dtype) updated_hidden = helper.create_tmp_variable(dtype) helper.append_op( type='gru_unit', inputs={'Input': input, 'HiddenPrev': hidden, 'Weight': weight}, outputs={ 'Gate': gate, 'ResetHiddenPrev': reset_hidden_pre, 'Hidden': updated_hidden, }, attrs={ 'activation': 0, 'gate_activation': 1, }) return updated_hidden, reset_hidden_pre, gate def linear_chain_crf(input, label, param_attr=None): helper = LayerHelper('linear_chain_crf', **locals()) size = input.shape[1] transition = helper.create_parameter( attr=helper.param_attr, shape=[size + 2, size], dtype=helper.input_dtype()) alpha = helper.create_tmp_variable(dtype=helper.input_dtype()) emission_exps = helper.create_tmp_variable(dtype=helper.input_dtype()) transition_exps = helper.create_tmp_variable(dtype=helper.input_dtype()) log_likelihood = helper.create_tmp_variable(dtype=helper.input_dtype()) helper.append_op( type='linear_chain_crf', inputs={"Emission": [input], "Transition": transition, "Label": label}, outputs={ "Alpha": [alpha], "EmissionExps": [emission_exps], "TransitionExps": transition_exps, "LogLikelihood": log_likelihood }) return log_likelihood def crf_decoding(input, param_attr, label=None): helper = LayerHelper('crf_decoding', **locals()) transition = helper.get_parameter(param_attr.name) viterbi_path = helper.create_tmp_variable(dtype=helper.input_dtype()) helper.append_op( type='crf_decoding', inputs={"Emission": [input], "Transition": transition, "Label": label}, outputs={"ViterbiPath": [viterbi_path]}) return viterbi_path def cos_sim(X, Y, **kwargs): """ This function performs the cosine similarity between two tensors X and Y and returns that as the output. """ helper = LayerHelper('cos_sim', **kwargs) out = helper.create_tmp_variable(dtype=X.dtype) xnorm = helper.create_tmp_variable(dtype=X.dtype) ynorm = helper.create_tmp_variable(dtype=X.dtype) helper.append_op( type='cos_sim', inputs={'X': [X], 'Y': [Y]}, outputs={'Out': [out], 'XNorm': [xnorm], 'YNorm': [ynorm]}) return out def cross_entropy(input, label, **kwargs): """ This function computes cross_entropy using the input and label. """ helper = LayerHelper('cross_entropy', **kwargs) out = helper.create_tmp_variable(dtype=input.dtype) helper.append_op( type='cross_entropy', inputs={'X': [input], 'Label': [label]}, outputs={'Y': [out]}, attrs=kwargs) return out def square_error_cost(input, label, **kwargs): """ This functions returns the squared error cost using the input and label. The output is appending the op to do the above. """ helper = LayerHelper('square_error_cost', **kwargs) minus_out = helper.create_tmp_variable(dtype=input.dtype) helper.append_op( type='elementwise_sub', inputs={'X': [input], 'Y': [label]}, outputs={'Out': [minus_out]}) square_out = helper.create_tmp_variable(dtype=input.dtype) helper.append_op( type='square', inputs={'X': [minus_out]}, outputs={'Y': [square_out]}) return square_out def accuracy(input, label, k=1, correct=None, total=None, **kwargs): """ This function computes the accuracy using the input and label. The output is the top_k inputs and their indices. """ helper = LayerHelper("accuracy", **kwargs) topk_out = helper.create_tmp_variable(dtype=input.dtype) topk_indices = helper.create_tmp_variable(dtype="int64") helper.append_op( type="top_k", inputs={"X": [input]}, outputs={"Out": [topk_out], "Indices": [topk_indices]}, attrs={"k": k}) acc_out = helper.create_tmp_variable(dtype="float32") if correct is None: correct = helper.create_tmp_variable(dtype="int64") if total is None: total = helper.create_tmp_variable(dtype="int64") helper.append_op( type="accuracy", inputs={ "Out": [topk_out], "Indices": [topk_indices], "Label": [label] }, outputs={ "Accuracy": [acc_out], "Correct": [correct], "Total": [total], }) return acc_out def chunk_eval(input, label, chunk_scheme, num_chunk_types, excluded_chunk_types=None, **kwargs): """ This function computes and outputs the precision, recall and F1-score of chunk detection. """ helper = LayerHelper("chunk_eval", **kwargs) # prepare output precision = helper.create_tmp_variable(dtype="float32") recall = helper.create_tmp_variable(dtype="float32") f1_score = helper.create_tmp_variable(dtype="float32") num_infer_chunks = helper.create_tmp_variable(dtype="int64") num_label_chunks = helper.create_tmp_variable(dtype="int64") num_correct_chunks = helper.create_tmp_variable(dtype="int64") helper.append_op( type="chunk_eval", inputs={"Inference": [input], "Label": [label]}, outputs={ "Precision": [precision], "Recall": [recall], "F1-Score": [f1_score], "NumInferChunks": [num_infer_chunks], "NumLabelChunks": [num_label_chunks], "NumCorrectChunks": [num_correct_chunks] }, attrs={ "num_chunk_types": num_chunk_types, "chunk_scheme": chunk_scheme, "excluded_chunk_types": excluded_chunk_types or [] }) return precision, recall, f1_score, num_infer_chunks, num_label_chunks, num_correct_chunks def sequence_conv(input, num_filters, filter_size=3, filter_stride=1, padding=None, bias_attr=None, param_attr=None, act=None): """ This function creates the op for sequence_conv, using the inputs and other convolutional configurations for the filters and stride as given in the input parameters to the function. """ # FIXME(dzh) : want to unify the argument of python layer # function. So we ignore some unecessary attributes. # such as, padding_trainable, context_start. helper = LayerHelper('sequence_conv', **locals()) dtype = helper.input_dtype() filter_shape = [filter_size * input.shape[1], num_filters] filter_param = helper.create_parameter( attr=helper.param_attr, shape=filter_shape, dtype=dtype) pre_bias = helper.create_tmp_variable(dtype) helper.append_op( type='sequence_conv', inputs={ 'X': [input], 'Filter': [filter_param], }, outputs={"Out": pre_bias}, attrs={ 'contextStride': filter_stride, 'contextStart': -int(filter_size / 2), 'contextLength': filter_size }) pre_act = helper.append_bias_op(pre_bias) return helper.append_activation(pre_act) def conv2d(input, num_filters, filter_size, stride=None, padding=None, groups=None, param_attr=None, bias_attr=None, act=None, name=None): """ This function creates the op for a 2-dimensional Convolution. This is performed using the parameters of filters(size, dimensionality etc) , stride and other configurations for a Convolution operation. This funciton can also append an activation on top of the conv-2d output, if mentioned in the input parameters. """ if stride is None: stride = [1, 1] helper = LayerHelper('conv2d', **locals()) dtype = helper.input_dtype() num_channels = input.shape[1] if groups is None: num_filter_channels = num_channels else: if num_channels % groups != 0: raise ValueError("num_channels must be divisible by groups.") num_filter_channels = num_channels / groups if isinstance(filter_size, int): filter_size = [filter_size, filter_size] if isinstance(stride, int): stride = [stride, stride] if isinstance(padding, int): padding = [padding, padding] input_shape = input.shape filter_shape = [num_filters, num_filter_channels] + filter_size def _get_default_param_initializer(): std = (2.0 / (filter_size[0]**2 * num_channels))**0.5 return Normal(0.0, std, 0) filter_param = helper.create_parameter( attr=helper.param_attr, shape=filter_shape, dtype=dtype, default_initializer=_get_default_param_initializer()) pre_bias = helper.create_tmp_variable(dtype) helper.append_op( type='conv2d_cudnn', inputs={ 'Input': input, 'Filter': filter_param, }, outputs={"Output": pre_bias}, attrs={'strides': stride, 'paddings': padding, 'groups': groups}) pre_act = helper.append_bias_op(pre_bias, dim_start=1, dim_end=2) return helper.append_activation(pre_act) def sequence_pool(input, pool_type, **kwargs): """ This function add the operator for sequence pooling. It pools features of all time-steps of each instance, and is applied on top of the input using pool_type mentioned in the parameters. It supports four pool_type: - average: :math:`Out[i] = \\frac{\sum_i X_i}{N}` - sum: :math:`Out[i] = \sum_jX_{ij}` - sqrt: :math:`Out[i] = \\frac{\sum_jX_{ij}}{\sqrt{len(X_i)}}` - max: :math:`Out[i] = max(X_i)` .. code-block:: text x is a 1-level LoDTensor: x.lod = [[0, 2, 5, 7]] x.data = [1, 3, 2, 4, 6, 5, 1] x.dims = [7, 1] then output is a Tensor: out.dim = [3, 1] with condition len(x.lod[-1]) - 1 == out.dims[0] for different pool_type: average: out.data = [2, 4, 3], where 2=(1+3)/2, 4=(2+4+6)/3, 3=(5+1)/2 sum : out.data = [4, 12, 6], where 4=1+3, 12=2+4+6, 6=5+1 sqrt : out.data = [2.82, 6.93, 4.24], where 2.82=(1+3)/sqrt(2), 6.93=(2+4+6)/sqrt(3), 4.24=(5+1)/sqrt(2) max : out.data = [3, 6, 5], where 3=max(1,3), 6=max(2,4,6), 5=max(5,1) Args: input(variable): The input variable which is a LoDTensor. pool_type (string): The pooling type of sequence_pool. It supports average, sum, sqrt and max. Returns: The sequence pooling variable which is a Tensor. Examples: .. code-block:: python x = fluid.layers.data(name='x', shape=[7, 1], dtype='float32', lod_level=1) avg_x = fluid.layers.sequence_pool(input=x, pool_type='average') sum_x = fluid.layers.sequence_pool(input=x, pool_type='sum') sqrt_x = fluid.layers.sequence_pool(input=x, pool_type='sqrt') max_x = fluid.layers.sequence_pool(input=x, pool_type='max') """ helper = LayerHelper('sequence_pool', input=input, **kwargs) dtype = helper.input_dtype() pool_out = helper.create_tmp_variable(dtype) max_index = helper.create_tmp_variable(dtype) helper.append_op( type="sequence_pool", inputs={"X": input}, outputs={"Out": pool_out, "MaxIndex": max_index}, attrs={"pooltype": pool_type.upper()}) return pool_out def sequence_first_step(input, **kwargs): return sequence_pool(input=input, pool_type="first") def sequence_last_step(input, **kwargs): return sequence_pool(input=input, pool_type="last") def pool2d(input, pool_size, pool_type, pool_stride=None, pool_padding=None, global_pooling=False): """ This function adds the operator for pooling in 2 dimensions, using the pooling configurations mentioned in input parameters. """ if pool_padding is None: pool_padding = [0, 0] if pool_stride is None: pool_stride = [1, 1] if pool_type not in ["max", "avg"]: raise ValueError( "Unknown pool_type: '%s'. It can only be 'max' or 'avg'.", str(pool_type)) if isinstance(pool_size, int): pool_size = [pool_size, pool_size] if isinstance(pool_stride, int): pool_stride = [pool_stride, pool_stride] if isinstance(pool_padding, int): pool_padding = [pool_padding, pool_padding] helper = LayerHelper('pool2d', **locals()) dtype = helper.input_dtype() pool_out = helper.create_tmp_variable(dtype) helper.append_op( type="pool2d", inputs={"X": input}, outputs={"Out": pool_out}, attrs={ "pooling_type": pool_type, "ksize": pool_size, "global_pooling": global_pooling, "strides": pool_stride, "paddings": pool_padding }) return pool_out def batch_norm(input, act=None, is_test=False, momentum=0.9, epsilon=1e-05, param_attr=None, bias_attr=None, data_layout='NCHW'): """ This function helps create an operator to implement the BatchNorm layer using the configurations from the input parameters. """ helper = LayerHelper('batch_norm', **locals()) dtype = helper.input_dtype() input_shape = input.shape if data_layout == 'NCHW': channel_num = input_shape[1] else: if data_layout == 'NHWC': channel_num = input_shape[-1] else: raise ValueError("unsupported data layout:" + data_layout) param_shape = [channel_num] # create parameter scale = helper.create_parameter( attr=helper.param_attr, shape=param_shape, dtype=dtype, default_initializer=Constant(1.0)) bias = helper.create_parameter( attr=helper.param_attr, shape=param_shape, dtype=dtype, is_bias=True) mean = helper.create_global_variable( dtype=input.dtype, shape=param_shape, persistable=True) helper.set_variable_initializer(var=mean, initializer=Constant(0.0)) variance = helper.create_global_variable( dtype=input.dtype, shape=param_shape, persistable=True) helper.set_variable_initializer(var=variance, initializer=Constant(1.0)) # create output # mean and mean_out share the same memory mean_out = mean # variance and variance out share the same memory variance_out = variance saved_mean = helper.create_tmp_variable(dtype) saved_variance = helper.create_tmp_variable(dtype) batch_norm_out = helper.create_tmp_variable(dtype) helper.append_op( type="batch_norm", inputs={ "X": input, "Scale": scale, "Bias": bias, "Mean": mean, "Variance": variance }, outputs={ "Y": batch_norm_out, "MeanOut": mean_out, "VarianceOut": variance_out, "SavedMean": saved_mean, "SavedVariance": saved_variance }, attrs={"momentum": momentum, "epsilon": epsilon, "is_test": is_test}) return helper.append_activation(batch_norm_out) def beam_search_decode(ids, scores): helper = LayerHelper('beam_search_decode', **locals()) sentence_ids = helper.create_tmp_variable(dtype=ids.dtype) sentence_scores = helper.create_tmp_variable(dtype=ids.dtype) helper.append_op( type="beam_search_decode", inputs={"Ids": ids, "Scores": scores}, outputs={ "SentenceIds": sentence_ids, "SentenceScores": sentence_scores }) return sentence_ids, sentence_scores def conv2d_transpose(input, num_filters, output_size=None, filter_size=None, padding=None, stride=None, param_attr=None): """ The transpose of conv2d layer. This layer is also known as deconvolution layer. Args: input(Variable): The input image with [N, C, H, W] format. num_filters(int): The number of filter. It is as same as the output image channel. output_size(int|tuple|None): The output image size. If output size is a tuple, it must contain two integers, (image_H, image_W). This parameter only works when filter_size is None. filter_size(int|tuple|None): The filter size. If filter_size is a tuple, it must contain two integers, (filter_size_H, filter_size_W). Otherwise, the filter will be a square. None if use output size to calculate filter_size padding(int|tuple): The padding size. If padding is a tuple, it must contain two integers, (padding_H, padding_W). Otherwise, the padding_H = padding_W = padding. stride(int|tuple): The stride size. If stride is a tuple, it must contain two integers, (stride_H, stride_W). Otherwise, the stride_H = stride_W = stride. param_attr: Parameter Attribute. main_program(Program): the main program startup_program(Program): the startup program Returns: Variable: Output image. """ helper = LayerHelper("conv2d_transpose", **locals()) if not isinstance(input, Variable): raise TypeError("Input of conv2d_transpose must be Variable") input_channel = input.shape[1] op_attr = dict() if isinstance(padding, int): op_attr['paddings'] = [padding, padding] elif padding is not None: op_attr['paddings'] = padding if isinstance(stride, int): op_attr['strides'] = stride elif stride is not None: op_attr['strides'] = stride if filter_size is None: if output_size is None: raise ValueError("output_size must be set when filter_size is None") if isinstance(output_size, int): output_size = [output_size, output_size] padding = op_attr.get('paddings', [0, 0]) stride = op_attr.get('strides', [1, 1]) h_in = input.shape[2] w_in = input.shape[3] filter_size_h = output_size[0] - \ (h_in - 1) * stride[0] + 2 * padding[0] filter_size_w = output_size[1] - \ (w_in - 1) * stride[1] + 2 * padding[1] filter_size = [filter_size_h, filter_size_w] elif isinstance(filter_size, int): filter_size = [filter_size, filter_size] filter_shape = [input_channel, num_filters] + filter_size img_filter = helper.create_parameter( dtype=input.dtype, shape=filter_shape, attr=helper.param_attr) out = helper.create_tmp_variable(dtype=input.dtype) helper.append_op( type='conv2d_transpose', inputs={'Input': [input], 'Filter': [img_filter]}, outputs={'Output': out}, attrs=op_attr) return out def sequence_expand(x, y): """Sequence Expand Layer. This layer will expand the input variable **x** according to LoD information of **y**. And the following examples will explain how sequence_expand works: .. code-block:: text * Case 1 x is a LoDTensor: x.lod = [[0, 2, 3], [0, 1, 3, 4]] x.data = [a, b, c, d] x.dims = [4, 1] y is a LoDTensor: y.lod = [[0, 2, 4], [0, 3, 6, 7, 8]] with condition len(y.lod[-1]) - 1 == x.dims[0] then output is a 2-level LoDTensor: out.lod = [[0, 2, 4], [0, 3, 6, 7, 8]] out.data = [a, a, a, b, b, b, c, d] out.dims = [8, 1] * Case 2 x is a Tensor: x.data = [a, b, c] x.dims = [3, 1] y is a LoDTensor: y.lod = [[0, 2, 3, 6]] with condition len(y.lod[-1]) - 1 == x.dims[0] then output is a 1-level LoDTensor: out.lod = [[0, 2, 3, 6]] out.data = [a, a, b, c, c, c] out.dims = [6, 1] Args: x (Variable): The input variable which is a Tensor or LoDTensor. y (Variable): The input variable which is a LoDTensor. Returns: Variable: The expanded variable which is a LoDTensor. Examples: .. code-block:: python x = fluid.layers.data(name='x', shape=[10], dtype='float32') y = fluid.layers.data(name='y', shape=[10, 20], dtype='float32', lod_level=1) out = layers.sequence_expand(x=x, y=y) """ helper = LayerHelper('sequence_expand', input=x, **locals()) dtype = helper.input_dtype() tmp = helper.create_tmp_variable(dtype) helper.append_op( type='sequence_expand', inputs={'X': x, 'Y': y}, outputs={'Out': tmp}) return tmp def lstm_unit(x_t, hidden_t_prev, cell_t_prev, forget_bias=0.0, param_attr=None, bias_attr=None): """Lstm unit layer. The equation of a lstm step is: .. math:: i_t & = \sigma(W_{x_i}x_{t} + W_{h_i}h_{t-1} + W_{c_i}c_{t-1} + b_i) f_t & = \sigma(W_{x_f}x_{t} + W_{h_f}h_{t-1} + W_{c_f}c_{t-1} + b_f) c_t & = f_tc_{t-1} + i_t tanh (W_{x_c}x_t+W_{h_c}h_{t-1} + b_c) o_t & = \sigma(W_{x_o}x_{t} + W_{h_o}h_{t-1} + W_{c_o}c_t + b_o) h_t & = o_t tanh(c_t) The inputs of lstm unit includes :math:`x_t`, :math:`h_{t-1}` and :math:`c_{t-1}`. The implementation separates the linear transformation and non-linear transformation apart. Here, we take :math:`i_t` as an example. The linear transformation is applied by calling a `fc` layer and the equation is: .. math:: L_{i_t} = W_{x_i}x_{t} + W_{h_i}h_{t-1} + W_{c_i}c_{t-1} + b_i The non-linear transformation is applied by calling `lstm_unit_op` and the equation is: .. math:: i_t = \sigma(L_{i_t}) This layer has two outputs including :math:`h_t` and :math:`o_t`. Args: x_t (Variable): The input value of current step. hidden_t_prev (Variable): The hidden value of lstm unit. cell_t_prev (Variable): The cell value of lstm unit. forget_bias (float): The forget bias of lstm unit. param_attr (ParamAttr): The attributes of parameter weights, used to set initializer, name etc. bias_attr (ParamAttr): The attributes of bias weights, if not False, bias weights will be created and be set to default value. Returns: tuple: The hidden value and cell value of lstm unit. Raises: ValueError: The ranks of **x_t**, **hidden_t_prev** and **cell_t_prev**\ not be 2 or the 1st dimensions of **x_t**, **hidden_t_prev** \ and **cell_t_prev** not be the same. Examples: .. code-block:: python x_t = fluid.layers.fc(input=x_t_data, size=10) prev_hidden = fluid.layers.fc(input=prev_hidden_data, size=20) prev_cell = fluid.layers.fc(input=prev_cell_data, size=30) hidden_value, cell_value = fluid.layers.lstm_unit(x_t=x_t, hidden_t_prev=prev_hidden, cell_t_prev=prev_cell) """ helper = LayerHelper('lstm_unit', **locals()) if len(x_t.shape) != 2: raise ValueError("Rank of x_t must be 2.") if len(hidden_t_prev.shape) != 2: raise ValueError("Rank of hidden_t_prev must be 2.") if len(cell_t_prev.shape) != 2: raise ValueError("Rank of cell_t_prev must be 2.") if x_t.shape[0] != hidden_t_prev.shape[0] or x_t.shape[ 0] != cell_t_prev.shape[0]: raise ValueError("The 1s dimension of x_t, hidden_t_prev and " "cell_t_prev must be the same.") if bias_attr is None: bias_attr = ParamAttr() size = cell_t_prev.shape[1] concat_out = concat(input=[x_t, hidden_t_prev], axis=1) fc_out = fc(input=concat_out, size=4 * size, param_attr=param_attr, bias_attr=bias_attr) dtype = x_t.dtype c = helper.create_tmp_variable(dtype) h = helper.create_tmp_variable(dtype) helper.append_op( type='lstm_unit', inputs={"X": fc_out, "C_prev": cell_t_prev}, outputs={"C": c, "H": h}, attrs={"forget_bias": forget_bias}) return h, c def reduce_sum(input, dim=None, keep_dim=False): """ Computes the sum of tensor elements over the given dimension. Args: input (Variable): The input variable which is a Tensor or LoDTensor. dim (int|None): The dimension along which the sum is performed. If :attr:`None`, sum all elements of :attr:`input` and return a Tensor variable with a single element, otherwise must be in the range :math:`[-rank(input), rank(input))`. If :math:`dim < 0`, the dimension to reduce is :math:`rank + dim`. keep_dim (bool): Whether to reserve the reduced dimension in the output Tensor. The result tensor will have one fewer dimension than the :attr:`input` unless :attr:`keep_dim` is true. Returns: Variable: The reduced Tensor variable. Examples: .. code-block:: python # x is a Tensor variable with following elements: # [[0.2, 0.3, 0.5, 0.9] # [0.1, 0.2, 0.6, 0.7]] # Each example is followed by the correspending output tensor. fluid.layers.reduce_sum(x) # [3.5] fluid.layers.reduce_sum(x, dim=0) # [0.3, 0.5, 1.1, 1.6] fluid.layers.reduce_sum(x, dim=-1) # [1.9, 1.6] fluid.layers.reduce_sum(x, dim=1, keep_dim=True) # [[1.9], [1.6]] """ helper = LayerHelper('reduce_sum', **locals()) out = helper.create_tmp_variable(dtype=helper.input_dtype()) helper.append_op( type='reduce_sum', inputs={'X': input}, outputs={'Out': out}, attrs={ 'dim': dim if dim != None else 0, 'keep_dim': keep_dim, 'reduce_all': True if dim == None else False }) return out