getLayer

Look up a layer by name or path

Since R2024a

Syntax

layer = getLayer(net,layerName)

layer = getLayer(net,layerPath)

Description

layer = getLayer(net,layerName) returns the layer specified by layerName from the dlnetwork object net.

layer = getLayer(net,layerPath) returns the layer specified by layerPath from the dlnetwork object net.

Examples

Get Layer from Neural Network

Define a simple network architecture and display the network in a plot.

net = dlnetwork;

layers = [
    imageInputLayer([28 28])
    convolution2dLayer(3,16,Padding="same")
    reluLayer
    fullyConnectedLayer(10)
    softmaxLayer];

net = addLayers(net,layers);

figure
plot(net)

Look up the convolution layer by name. You can then edit the layer and replace it using the getLayer function.

convLayer = getLayer(net,"conv")

convLayer = 
  Convolution2DLayer with properties:

              Name: 'conv'

   Hyperparameters
        FilterSize: [3 3]
       NumChannels: 'auto'
        NumFilters: 16
            Stride: [1 1]
    DilationFactor: [1 1]
       PaddingMode: 'same'
       PaddingSize: []
      PaddingValue: 0

   Learnable Parameters
           Weights: []
              Bias: []

Use properties method to see a list of all properties.

If you know the index of the layer, you can alternatively look it up by index.

convLayer = net.Layers(2);

Replace Layer in Nested Network

Define a network architecture containing several network layers.

net = dlnetwork;

layers = [lstmLayer(100,OutputMode="sequence")
    dropoutLayer(0.2)];

lstmDropoutLayer = networkLayer(layers);

layers = [sequenceInputLayer(3)
    lstmDropoutLayer
    lstmDropoutLayer
    fullyConnectedLayer(10)
    softmaxLayer];

net = addLayers(net,layers);

Plot the network.

figure
plot(net)

Look up the first LSTM layer by specifying the path to the layer. The path includes the name of the network layer ("subnet_1") and the name of the LSTM layer ("lstm"), separated by a forward slash. You can use the path to look up layers nested within a hierarchy of multiple network layers.

tempLSTMLayer = getLayer(net,"subnet_1/lstm");

Edit properties of the layer, and replace the original layer with the modified layer.

tempLSTMLayer.InputWeightsInitializer = "zeros";
tempLSTMLayer.RecurrentWeightsInitializer = "zeros";
tempLSTMLayer.BiasInitializer = "ones";
tempLSTMLayer.Name = "modifiedLSTM";

Replace the original layer with the modified layer, specifying the network, the path to the layer to replace, and the modified layer.

net = replaceLayer(net,"subnet_1/lstm",tempLSTMLayer);

Input Arguments

net — Neural network

dlnetwork object

Neural network, specified as a dlnetwork object.

layerName — Name of layer

character vector | string scalar

Name of layer to look up, specified as a character vector or string scalar.

Example: "conv1"

Data Types: char | string

layerPath — Path to nested layer

character vector | string scalar

Path to nested layer, specified as a character vector or string scalar.

For a layer within a networkLayer, specify layerPath as:

• The name of the network layer and the name of the nested layer separated by a forward slash "/". For example, the path to a layer named "nestedLayerName" in a network layer named "networkLayerName" is "networkLayerName/nestedLayerName". If there are multiple levels of nested layers, then specify the path using the form networkLayerName1/.../networkLayerNameN/nestedLayerName.

Custom layers can have a dlnetwork as a learnable or state property. For a layer of a dlnetwork in the property of a custom layer, specify layerPath as:

• The name of the custom layer, the name of the dlnetwork property, and the name of the nested layer separated by forward slashes "/". For example, the path to a layer named "layerName" inside a dlnetwork property named "propertyName" of a custom layer named "customLayerName" is "customLayerName/propertyName/layerName". If there are multiple levels of nested layers, then specify the path using the form "customLayerName1/propertyName1/.../customLayerNameN/propertyNameN/layerName".

Data Types: char | string

Version History

Introduced in R2024a