Graph (owl-base.Owl_neural_generic.Flatten.Graph)

module Neuron : Owl_neural_neuron_sig.Sig

Type definition

type node = {

mutable name : string;
mutable prev : node array;
mutable next : node array;
mutable neuron : Neuron.neuron;
mutable output : Neuron.Optimise.Algodiff.t option;
mutable network : network;
mutable train : bool;

}

and network = {

mutable nnid : string;
mutable size : int;
mutable roots : node array;
mutable outputs : node array;
mutable topo : node array;

}

Type definition of a node and a neural network.

Manipulate networks

val make_network : ?nnid:string -> int -> node array -> node array -> network

Create an empty neural network.

val make_node : 
  ?name:string ->
  ?train:bool ->
  node array ->
  node array ->
  Neuron.neuron ->
  Neuron.Optimise.Algodiff.t option ->
  network ->
  node

Create a node in a neural network.

val get_roots : network -> node array

Get the roots of the neural network.

val get_outputs : network -> node array

Get the outputs of the neural network.

val get_node : network -> string -> node

Get a node in a network with the given name.

val get_network : ?name:string -> node -> network

Get the neural network of a given node associated with.

val outputs : ?name:string -> node array -> network

Get the neural network associated with the given output nodes.

val get_network_name : network -> string

get_network_name n returns the name of the network n.

val set_network_name : network -> string -> unit

set_network_name n s sets the name of the network n to s.

val collect_output : node array -> Neuron.Optimise.Algodiff.t array

Collect the output values of given nodes.

val connect_pair : node -> node -> unit

Connect two nodes in a neural network.

val connect_to_parents : node array -> node -> unit

Connect a node to a list of parents.

val add_node : 
  ?act_typ:Neuron.Activation.typ ->
  network ->
  node array ->
  node ->
  node

Add a node to the given network.

val input_shape : network -> int array

Get input shape of a network (without batch dimension), i.e. shape of input neuron.

val input_shapes : network -> int array array

Get input shapes of a network (without batch dimension), i.e. shape of input neurons.

Interface to optimisation engine

val init : network -> unit

Initialise the network.

val reset : network -> unit

Reset the network, i.e. all the parameters in the neurons.

val mktag : int -> network -> unit

Tag the neurons, used by Algodiff module.

val mkpar : network -> Neuron.Optimise.Algodiff.t array array

Collect the parameters of neurons, used by Optimise module.

val mkpri : network -> Neuron.Optimise.Algodiff.t array array

Collect the primal values of neurons, used by Optimise module.

val mkadj : network -> Neuron.Optimise.Algodiff.t array array

Collect the adjacent values of neurons, used by Optimise module.

val update : network -> Neuron.Optimise.Algodiff.t array array -> unit

Update the parameters of neurons, used by Optimise module.

val run : Neuron.Optimise.Algodiff.t -> network -> Neuron.Optimise.Algodiff.t

Execute the computations in all the neurons in a network with the given input.

val run_inputs : 
  Neuron.Optimise.Algodiff.t array ->
  network ->
  Neuron.Optimise.Algodiff.t array

Execute the computations in all the neurons in a network with the given inputs.

val forward : 
  network ->
  Neuron.Optimise.Algodiff.t ->
  Neuron.Optimise.Algodiff.t * Neuron.Optimise.Algodiff.t array array

Run the forward pass of a network.

val forward_inputs : 
  network ->
  Neuron.Optimise.Algodiff.t array ->
  Neuron.Optimise.Algodiff.t array * Neuron.Optimise.Algodiff.t array array

Run the forward pass of a network (multi-input/output version).

val backward : 
  network ->
  Neuron.Optimise.Algodiff.t ->
  Neuron.Optimise.Algodiff.t array array
  * Neuron.Optimise.Algodiff.t array array

Run the backward pass of a network.

val copy : network -> network

Make a deep copy of the given network.

val model : 
  network ->
  Neuron.Optimise.Algodiff.A.arr ->
  Neuron.Optimise.Algodiff.A.arr

Make a deep copy of the given network, excluding the neurons marked with training = true.

val model_inputs : 
  network ->
  Neuron.Optimise.Algodiff.A.arr array ->
  Neuron.Optimise.Algodiff.A.arr array

Make a deep copy of the given network, excluding the neurons marked with training = true.

Create Neurons

val input : ?name:string -> int array -> node

input shape creates an input node for input data. Note that if your network has multiple inputs, you should use inputs instead.

Arguments: * shape: shape of input data.

val inputs : ?names:string array -> int array array -> node array

input shapes creates an array of input nodes for input data.

Arguments: * shapes: array of shapes of input data.

val activation : ?name:string -> Neuron.Activation.typ -> node -> node

Applies an activation function to an output.

Arguments: * activation: name of activation function to use.

val linear : 
  ?name:string ->
  ?init_typ:Neuron.Init.typ ->
  ?act_typ:Neuron.Activation.typ ->
  int ->
  node ->
  node

linear ?act_typ units node adds the regular densely-connected NN node to node.

Arguments: * units: Positive integer, dimensionality of the output space. * act_typ: Activation function to use.

val linear_nobias : 
  ?name:string ->
  ?init_typ:Neuron.Init.typ ->
  ?act_typ:Neuron.Activation.typ ->
  int ->
  node ->
  node

Similar to linear, but does not use the bias vector.

val embedding : 
  ?name:string ->
  ?init_typ:Neuron.Init.typ ->
  ?act_typ:Neuron.Activation.typ ->
  int ->
  int ->
  node ->
  node

Create a node for embedding neuron.

val recurrent : 
  ?name:string ->
  ?init_typ:Neuron.Init.typ ->
  act_typ:Neuron.Activation.typ ->
  int ->
  int ->
  node ->
  node

Create a node for recurrent neuron.

val lstm : ?name:string -> ?init_typ:Neuron.Init.typ -> int -> node -> node

lstm units node adds a LSTM node on previous node.

Arguments: * units: Positive integer, dimensionality of the output space.

val gru : ?name:string -> ?init_typ:Neuron.Init.typ -> int -> node -> node

gru units node adds a Gated Recurrent Unit node on previous node.

Arguments: * units: Positive integer, dimensionality of the output space.

val conv1d : 
  ?name:string ->
  ?padding:Owl_types.padding ->
  ?init_typ:Neuron.Init.typ ->
  ?act_typ:Neuron.Activation.typ ->
  int array ->
  int array ->
  node ->
  node

conv1d kernel stride node adds a 1D convolution node (e.g. temporal convolution) on previous node.

Arguments: * kernel: int array consists of h, i, o. h specifies the dimension of the 1D convolution window. i and o are the dimensionalities of the input and output space. * stride: int array of 1 integer.

val conv2d : 
  ?name:string ->
  ?padding:Owl_types.padding ->
  ?init_typ:Neuron.Init.typ ->
  ?act_typ:Neuron.Activation.typ ->
  int array ->
  int array ->
  node ->
  node

conv2d kernel stride node adds a 2D convolution node (e.g. spatial convolution over images) on previous node.

Arguments: * kernel: int array consists of w, h, i, o. w and h specify the width and height of the 2D convolution window. i and o are the dimensionality of the input and output space. * stride: int array of 2 integers.

val conv3d : 
  ?name:string ->
  ?padding:Owl_types.padding ->
  ?init_typ:Neuron.Init.typ ->
  ?act_typ:Neuron.Activation.typ ->
  int array ->
  int array ->
  node ->
  node

conv3d kernel stride node adds a 3D convolution node (e.g. spatial convolution over volumes) on previous node.

Arguments: * kernel: int array consists of w, h, d, i, o. w, h, and d specify the 3 dimensionality of the 3D convolution window. i and o are the dimensionality of the input and output space. * stride: int array of 3 integers.

val dilated_conv1d : 
  ?name:string ->
  ?padding:Owl_types.padding ->
  ?init_typ:Neuron.Init.typ ->
  ?act_typ:Neuron.Activation.typ ->
  int array ->
  int array ->
  int array ->
  node ->
  node

dilated_conv1d kernel stride rate node adds a 1D dilated convolution node (e.g. temporal convolution) on previous node.

val dilated_conv2d : 
  ?name:string ->
  ?padding:Owl_types.padding ->
  ?init_typ:Neuron.Init.typ ->
  ?act_typ:Neuron.Activation.typ ->
  int array ->
  int array ->
  int array ->
  node ->
  node

dilated_conv2d kernel stride rate node adds a 2D dilated convolution node (e.g. spatial convolution over images) on previous node.

Arguments: * kernel`: int array consists of w, h, i, o. w and h specify the width and height of the 2D convolution window. i and o`` are the dimensionality of the input and output space. * stride: int array of 2 integers. * rate: int array of 2 integers.

val dilated_conv3d : 
  ?name:string ->
  ?padding:Owl_types.padding ->
  ?init_typ:Neuron.Init.typ ->
  ?act_typ:Neuron.Activation.typ ->
  int array ->
  int array ->
  int array ->
  node ->
  node

dilated_conv3d kernel stride rate node adds a 3D dilated convolution node (e.g. spatial convolution over volumes) on previous node.

val transpose_conv1d : 
  ?name:string ->
  ?padding:Owl_types.padding ->
  ?init_typ:Neuron.Init.typ ->
  ?act_typ:Neuron.Activation.typ ->
  int array ->
  int array ->
  node ->
  node

transpose_conv1d kernel stride node adds a 1D transpose convolution node (e.g. temporal convolution) on previous node.

val transpose_conv2d : 
  ?name:string ->
  ?padding:Owl_types.padding ->
  ?init_typ:Neuron.Init.typ ->
  ?act_typ:Neuron.Activation.typ ->
  int array ->
  int array ->
  node ->
  node

transpose_conv2d kernel stride node adds a 2D transpose convolution node on previous node.

val transpose_conv3d : 
  ?name:string ->
  ?padding:Owl_types.padding ->
  ?init_typ:Neuron.Init.typ ->
  ?act_typ:Neuron.Activation.typ ->
  int array ->
  int array ->
  node ->
  node

transpose_conv3d kernel stride node adds a 3D transpose convolution node (e.g. spatial convolution over volumes) on previous node.

val fully_connected : 
  ?name:string ->
  ?init_typ:Neuron.Init.typ ->
  ?act_typ:Neuron.Activation.typ ->
  int ->
  node ->
  node

fully_connected outputs node adds a fully connected node to node.

Arguments: * outputs: integer, the number of output units in the node.

val max_pool1d : 
  ?name:string ->
  ?padding:Owl_types.padding ->
  ?act_typ:Neuron.Activation.typ ->
  int array ->
  int array ->
  node ->
  node

max_pool1d ~padding ~act_typ pool_size stride node adds a max pooling operation for temporal data to node.

Arguments: * pool_size: Array of one integer, size of the max pooling windows. * stride: Array of one integer, factor by which to downscale.

val max_pool2d : 
  ?name:string ->
  ?padding:Owl_types.padding ->
  ?act_typ:Neuron.Activation.typ ->
  int array ->
  int array ->
  node ->
  node

max_pool2d ~padding ~act_typ pool_size stride node adds a max pooling operation for spatial data to node.

Arguments: * pool_size: Array of 2 integers, size of the max pooling windows. * stride: Array of 2 integers, factor by which to downscale.

val avg_pool1d : 
  ?name:string ->
  ?padding:Owl_types.padding ->
  ?act_typ:Neuron.Activation.typ ->
  int array ->
  int array ->
  node ->
  node

avg_pool1d ~padding ~act_typ pool_size stride node adds a average pooling operation for temporal data to node.

Arguments: * pool_size: Array of one integer, size of the max pooling windows. * stride: Array of one integer, factor by which to downscale.

val avg_pool2d : 
  ?name:string ->
  ?padding:Owl_types.padding ->
  ?act_typ:Neuron.Activation.typ ->
  int array ->
  int array ->
  node ->
  node

avg_pool2d ~padding ~act_typ pool_size stride node adds a average pooling operation for spatial data to node.

Arguments: * pool_size: Array of 2 integers, size of the max pooling windows. * stride: Array of 2 integers, factor by which to downscale.

val global_max_pool1d : 
  ?name:string ->
  ?act_typ:Neuron.Activation.typ ->
  node ->
  node

global_max_pool1d adds global max pooling operation for temporal data.

val global_max_pool2d : 
  ?name:string ->
  ?act_typ:Neuron.Activation.typ ->
  node ->
  node

global_max_poo2d global max pooling operation for spatial data.

val global_avg_pool1d : 
  ?name:string ->
  ?act_typ:Neuron.Activation.typ ->
  node ->
  node

global_avg_pool1d adds global average pooling operation for temporal data.

val global_avg_pool2d : 
  ?name:string ->
  ?act_typ:Neuron.Activation.typ ->
  node ->
  node

global_avg_poo2d global average pooling operation for spatial data.

val upsampling2d : 
  ?name:string ->
  ?act_typ:Neuron.Activation.typ ->
  int array ->
  node ->
  node

upsampling2d ~act_typ size node adds a upsampling operation for spatial data to node.

Arguments: * size: array of two integers, namely the upsampling factors for columns and rows.

val padding2d : 
  ?name:string ->
  ?act_typ:Neuron.Activation.typ ->
  int array array ->
  node ->
  node

padding2d ~act_typ padding node adds rows and columns of zeros at the top, bottom, left and right side of an image tensor.

Arguments: * padding: array of 2 arrays of 2 integers, interpreted as | [|top_pad; bottom_pad|]; [|left_pad; right_pad|]|.

val dropout : ?name:string -> float -> node -> node

dropout rate node applies Dropout to the input to prevent overfitting.

Arguments: * rate: float between 0 and 1. Fraction of the input units to drop.

val gaussian_noise : ?name:string -> float -> node -> node

gaussian_noise stddev node applies additive zero-centered Gaussian noise.

Arguments: * stddev: float, standard deviation of the noise distribution.

val gaussian_dropout : ?name:string -> float -> node -> node

gaussian_dropout rate node applies multiplicative 1-centered Gaussian noise. Only active at training time.

Arguments: * rates: float, drop probability

val alpha_dropout : ?name:string -> float -> node -> node

alpha_dropout rate node applies Alpha Dropout to the input node. Only active at training time.

Arguments: * rates: float, drop probability

val normalisation : 
  ?name:string ->
  ?axis:int ->
  ?training:bool ->
  ?decay:float ->
  ?mu:Neuron.Optimise.Algodiff.A.arr ->
  ?var:Neuron.Optimise.Algodiff.A.arr ->
  node ->
  node

normalisation axis node normalise the activations of the previous node at each batch.

Arguments: * axis: Integer, the axis that should be normalised (typically the features axis). Default value is 0.

val reshape : ?name:string -> int array -> node -> node

reshape target_shape node reshapes an output to a certain shape.

Arguments: * target_shape: target shape. Array of integers. Does not include the batch axis.

val flatten : ?name:string -> node -> node

flatten node flattens the input. Does not affect the batch size.

val slice : ?name:string -> int list list -> node -> node

slice node slices the input. Does not affect the batch size.

val lambda : 
  ?name:string ->
  ?act_typ:Neuron.Activation.typ ->
  ?out_shape:int array ->
  (Neuron.Optimise.Algodiff.t -> Neuron.Optimise.Algodiff.t) ->
  node ->
  node

lambda ?target_shape func node wraps arbitrary expression as a Node object.

Arguments: * func: The function to be evaluated. Takes input tensor as first argument. * target_shape: the shape of the tensor returned by func; set to the same as input shape if not specified.

val lambda_array : 
  ?name:string ->
  ?act_typ:Neuron.Activation.typ ->
  int array ->
  (Neuron.Optimise.Algodiff.t array -> Neuron.Optimise.Algodiff.t) ->
  node array ->
  node

lambda_array target_shape func node wraps arbitrary expression as a Node object.

Arguments: * target_shape: the shape of the tensor returned by func. * func: The function to be evaluated. Takes input tensor array as first argument.

val add : ?name:string -> ?act_typ:Neuron.Activation.typ -> node array -> node

Node that adds a list of inputs.

It takes as input an array of nodes, all of the same shape, and returns a single node (also of the same shape).

val mul : ?name:string -> ?act_typ:Neuron.Activation.typ -> node array -> node

Node that multiplies (element-wise) a list of inputs.

It takes as input an array of nodes, all of the same shape, and returns a single node (also of the same shape).

val dot : ?name:string -> ?act_typ:Neuron.Activation.typ -> node array -> node

Node that computes a dot product between samples in two nodes.

val max : ?name:string -> ?act_typ:Neuron.Activation.typ -> node array -> node

Node that computes the maximum (element-wise) a list of inputs.

val average : 
  ?name:string ->
  ?act_typ:Neuron.Activation.typ ->
  node array ->
  node

Node that averages a list of inputs.

It takes as input an array of nodes, all of the same shape, and returns a single node (also of the same shape).

val concatenate : 
  ?name:string ->
  ?act_typ:Neuron.Activation.typ ->
  int ->
  node array ->
  node

concatenate axis nodes concatenates a array of nodes and return as a single node.

Arguments: * axis: Axis along which to concatenate.

Helper functions

val to_string : network -> string

Convert a neural network to its string representation.

val pp_network : Stdlib.Format.formatter -> network -> unit

Pretty printing function a neural network.

val print : network -> unit

Print the string representation of a neural network to the standard output.

val save : ?unsafe:bool -> network -> string -> unit

Serialise a network and save it to the a file with the given name. Set the unsafe flag to true if network contains Lambda layer.

val load : string -> network

Load the neural network from a file with the given name.

val save_weights : network -> string -> unit

Save all the weights in a neural network to a file. The weights and the name of their associated neurons are saved as key-value pairs in a hash table.

val load_weights : network -> string -> unit

Load the weights from a file of the given name. Note that the weights and the name of their associated neurons are saved as key-value pairs in a hash table.

val make_subnetwork : 
  ?copy:bool ->
  ?make_inputs:string array ->
  network ->
  string array ->
  network

get_subnetwork ?copy ?make_inputs network output_names constructs a subnetwork of nodes on which output_names depend, replacing nodes with names in make_inputs with input nodes.

Arguments: copy: Whether to copy or reference the original node weights. Defaults to true. make_inputs: Names of nodes to use as inputs to the subnetwork. Defaults to ||, which uses the original inputs. nn: The neural network from which the subnetwork is constructed. output_names: Names of nodes to use as outputs.

Train Networks

val train_generic : 
  ?state:Neuron.Optimise.Checkpoint.state ->
  ?params:Neuron.Optimise.Params.typ ->
  ?init_model:bool ->
  network ->
  Neuron.Optimise.Algodiff.t ->
  Neuron.Optimise.Algodiff.t ->
  Neuron.Optimise.Checkpoint.state

Generic function of training a neural network.

val train : 
  ?state:Neuron.Optimise.Checkpoint.state ->
  ?params:Neuron.Optimise.Params.typ ->
  ?init_model:bool ->
  network ->
  Neuron.Optimise.Algodiff.A.arr ->
  Neuron.Optimise.Algodiff.A.arr ->
  Neuron.Optimise.Checkpoint.state

Train a neural network with various configurations.