R/layers-convolutional.R

layer_separable_conv_1d

Depthwise separable 1D convolution.

Description

Separable convolutions consist in first performing a depthwise spatial convolution (which acts on each input channel separately) followed by a pointwise convolution which mixes together the resulting output channels. The depth_multiplier argument controls how many output channels are generated per input channel in the depthwise step. Intuitively, separable convolutions can be understood as a way to factorize a convolution kernel into two smaller kernels, or as an extreme version of an Inception block.

Usage

 
layer_separable_conv_1d( 
  object, 
  filters, 
  kernel_size, 
  strides = 1, 
  padding = "valid", 
  data_format = "channels_last", 
  dilation_rate = 1, 
  depth_multiplier = 1, 
  activation = NULL, 
  use_bias = TRUE, 
  depthwise_initializer = "glorot_uniform", 
  pointwise_initializer = "glorot_uniform", 
  bias_initializer = "zeros", 
  depthwise_regularizer = NULL, 
  pointwise_regularizer = NULL, 
  bias_regularizer = NULL, 
  activity_regularizer = NULL, 
  depthwise_constraint = NULL, 
  pointwise_constraint = NULL, 
  bias_constraint = NULL, 
  input_shape = NULL, 
  batch_input_shape = NULL, 
  batch_size = NULL, 
  dtype = NULL, 
  name = NULL, 
  trainable = NULL, 
  weights = NULL 
) 

Arguments

Arguments Description
object What to compose the new Layer instance with. Typically a Sequential model or a Tensor (e.g., as returned by layer_input()). The return value depends on object. If object is:
- missing or NULL, the Layer instance is returned.
- a Sequential model, the model with an additional layer is returned.
- a Tensor, the output tensor from layer_instance(object) is returned.
filters Integer, the dimensionality of the output space (i.e. the number of output filters in the convolution).
kernel_size An integer or list of 2 integers, specifying the width and height of the 2D convolution window. Can be a single integer to specify the same value for all spatial dimensions.
strides An integer or list of 2 integers, specifying the strides of the convolution along the width and height. Can be a single integer to specify the same value for all spatial dimensions. Specifying any stride value != 1 is incompatible with specifying any dilation_rate value != 1.
padding one of "valid" or "same" (case-insensitive).
data_format A string, one of channels_last (default) or channels_first. The ordering of the dimensions in the inputs. channels_last corresponds to inputs with shape (batch, height, width, channels) while channels_first corresponds to inputs with shape (batch, channels, height, width). It defaults to the image_data_format value found in your Keras config file at ~/.keras/keras.json. If you never set it, then it will be “channels_last”.
dilation_rate an integer or list of 2 integers, specifying the dilation rate to use for dilated convolution. Can be a single integer to specify the same value for all spatial dimensions. Currently, specifying any dilation_rate value != 1 is incompatible with specifying any stride value != 1.
depth_multiplier The number of depthwise convolution output channels for each input channel. The total number of depthwise convolution output channels will be equal to filters_in * depth_multiplier.
activation Activation function to use. If you don’t specify anything, no activation is applied (ie. “linear” activation: a(x) = x).
use_bias Boolean, whether the layer uses a bias vector.
depthwise_initializer Initializer for the depthwise kernel matrix.
pointwise_initializer Initializer for the pointwise kernel matrix.
bias_initializer Initializer for the bias vector.
depthwise_regularizer Regularizer function applied to the depthwise kernel matrix.
pointwise_regularizer Regularizer function applied to the pointwise kernel matrix.
bias_regularizer Regularizer function applied to the bias vector.
activity_regularizer Regularizer function applied to the output of the layer (its “activation”)..
depthwise_constraint Constraint function applied to the depthwise kernel matrix.
pointwise_constraint Constraint function applied to the pointwise kernel matrix.
bias_constraint Constraint function applied to the bias vector.
input_shape Dimensionality of the input (integer) not including the samples axis. This argument is required when using this layer as the first layer in a model.
batch_input_shape Shapes, including the batch size. For instance, batch_input_shape=c(10, 32) indicates that the expected input will be batches of 10 32-dimensional vectors. batch_input_shape=list(NULL, 32) indicates batches of an arbitrary number of 32-dimensional vectors.
batch_size Fixed batch size for layer
dtype The data type expected by the input, as a string (float32, float64, int32…)
name An optional name string for the layer. Should be unique in a model (do not reuse the same name twice). It will be autogenerated if it isn’t provided.
trainable Whether the layer weights will be updated during training.
weights Initial weights for layer.

Section

Input shape

3D tensor with shape: (batch, channels, steps) if data_format=‘channels_first’ or 3D tensor with shape: (batch, steps, channels) if data_format=‘channels_last’.

Output shape

3D tensor with shape: (batch, filters, new_steps) if data_format=‘channels_first’ or 3D tensor with shape: (batch, new_steps, filters) if data_format=‘channels_last’. new_steps values might have changed due to padding or strides.

See Also

Other convolutional layers: layer_conv_1d_transpose(), layer_conv_1d(), layer_conv_2d_transpose(), layer_conv_2d(), layer_conv_3d_transpose(), layer_conv_3d(), layer_conv_lstm_2d(), layer_cropping_1d(), layer_cropping_2d(), layer_cropping_3d(), layer_depthwise_conv_1d(), layer_depthwise_conv_2d(), layer_separable_conv_2d(), layer_upsampling_1d(), layer_upsampling_2d(), layer_upsampling_3d(), layer_zero_padding_1d(), layer_zero_padding_2d(), layer_zero_padding_3d()