network

Create custom shallow neural network

Syntax

net = network net = network(numInputs,numLayers,biasConnect,inputConnect,layerConnect,outputConnect)

To Get Help

Type help network/network.

Tip

To learn how to create a deep learning network, see dlnetwork.

Description

network creates new custom networks. It is used to create networks that are then customized by functions such as feedforwardnet and narxnet.

net = network without arguments returns a new neural network with no inputs, layers or outputs.

net = network(numInputs,numLayers,biasConnect,inputConnect,layerConnect,outputConnect) takes these optional arguments (shown with default values):

`numInputs`	Number of inputs, 0
`numLayers`	Number of layers, 0
`biasConnect`	`numLayers`-by-1 Boolean vector, zeros
`inputConnect`	`numLayers`-by-`numInputs` Boolean matrix, zeros
`layerConnect`	`numLayers`-by-`numLayers` Boolean matrix, zeros
`outputConnect`	1-by-`numLayers` Boolean vector, zeros

and returns

net

New network with the given property values

Properties

Architecture Properties

`net.numInputs`	0 or a positive integer	Number of inputs.
`net.numLayers`	0 or a positive integer	Number of layers.
`net.biasConnect`	`numLayer`-by-1 Boolean vector	If `net.biasConnect(i)` is 1, then layer `i` has a bias, and `net.biases{i}` is a structure describing that bias.
`net.inputConnect`	`numLayer`-by-`numInputs` Boolean vector	If `net.inputConnect(i,j)` is 1, then layer `i` has a weight coming from input `j`, and `net.inputWeights{i,j}` is a structure describing that weight.
`net.layerConnect`	`numLayer`-by-`numLayers` Boolean vector	If `net.layerConnect(i,j)` is 1, then layer `i` has a weight coming from layer `j`, and `net.layerWeights{i,j}` is a structure describing that weight.
`net.outputConnect`	1-by-`numLayers` Boolean vector	If `net.outputConnect(i)` is 1, then the network has an output from layer `i`, and `net.outputs{i}` is a structure describing that output.
`net.numOutputs`	0 or a positive integer (read only)	Number of network outputs according to `net.outputConnect`.
`net.numInputDelays`	0 or a positive integer (read only)	Maximum input delay according to all `net.inputWeights{i,j}.delays`.
`net.numLayerDelays`	0 or a positive number (read only)	Maximum layer delay according to all `net.layerWeights{i,j}.delays`.

Subobject Structure Properties

`net.inputs`	`numInputs`-by-1 cell array	`net.inputs{i}` is a structure defining input `i`.
`net.layers`	`numLayers`-by-1 cell array	`net.layers{i}` is a structure defining layer `i`.
`net.biases`	`numLayers`-by-1 cell array	If `net.biasConnect(i)` is 1, then `net.biases{i}` is a structure defining the bias for layer `i`.
`net.inputWeights`	`numLayers`-by-`numInputs` cell array	If `net.inputConnect(i,j)` is 1, then `net.inputWeights{i,j}` is a structure defining the weight to layer `i` from input `j`.
`net.layerWeights`	`numLayers`-by-`numLayers` cell array	If `net.layerConnect(i,j)` is 1, then `net.layerWeights{i,j}` is a structure defining the weight to layer `i` from layer `j`.
`net.outputs`	1-by-`numLayers` cell array	If `net.outputConnect(i)` is 1, then `net.outputs{i}` is a structure defining the network output from layer `i`.

Function Properties

`net.adaptFcn`	Name of a network adaption function or `''`
`net.initFcn`	Name of a network initialization function or `''`
`net.performFcn`	Name of a network performance function or `''`
`net.trainFcn`	Name of a network training function or `''`

Parameter Properties

`net.adaptParam`	Network adaption parameters
`net.initParam`	Network initialization parameters
`net.performParam`	Network performance parameters
`net.trainParam`	Network training parameters

Weight and Bias Value Properties

`net.IW`	`numLayers`-by-`numInputs` cell array of input weight values
`net.LW`	`numLayers`-by-`numLayers` cell array of layer weight values
`net.b`	`numLayers`-by-1 cell array of bias values

Other Properties

net.userdata

Structure you can use to store useful values

Examples

Create Network with One Input and Two Layers

This example shows how to create a network without any inputs and layers, and then set its numbers of inputs and layers to 1 and 2 respectively.

net = network
net.numInputs = 1
net.numLayers = 2

Alternatively, you can create the same network with one line of code.

net = network(1,2)

Create Feedforward Network and View Properties

This example shows how to create a one-input, two-layer, feedforward network. Only the first layer has a bias. An input weight connects to layer 1 from input 1. A layer weight connects to layer 2 from layer 1. Layer 2 is a network output and has a target.

net = network(1,2,[1;0],[1; 0],[0 0; 1 0],[0 1])

You can view the network subobjects with the following code.

net.inputs{1}
net.layers{1}, net.layers{2}
net.biases{1}
net.inputWeights{1,1}, net.layerWeights{2,1}
net.outputs{2}

You can alter the properties of any of the network subobjects. This code changes the transfer functions of both layers:

net.layers{1}.transferFcn = 'tansig';
net.layers{2}.transferFcn = 'logsig';

You can view the weights for the connection from the first input to the first layer as follows. The weights for a connection from an input to a layer are stored in net.IW. If the values are not yet set, these result is empty.

net.IW{1,1}

You can view the weights for the connection from the first layer to the second layer as follows. Weights for a connection from a layer to a layer are stored in net.LW. Again, if the values are not yet set, the result is empty.

net.LW{2,1}

You can view the bias values for the first layer as follows.

net.b{1}

To change the number of elements in input 1 to 2, set each element’s range:

net.inputs{1}.range = [0 1; -1 1];

After training your network, you can use sim to simulate the network. For example, simulate the network for a two-element input vector.

p = [0.5; -0.1];
y = sim(net,p)

Version History

Introduced before R2006a