relu - Apply rectified linear unit activation - MATLAB (original) (raw)

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Apply rectified linear unit activation

Syntax

Description

The rectified linear unit (ReLU) activation operation performs a nonlinear threshold operation, where any input value less than zero is set to zero.

This operation is equivalent to:

Note

This function applies the ReLU operation to dlarray data. If you want to apply the ReLU activation within a dlnetwork object, use reluLayer.

[Y](#mw%5Fe846e5fa-9f33-42d6-981e-70e8c6e2b228) = relu([X](#mw%5F828f6995-4c13-4c4b-81ec-542fd551a753%5Fsep%5Fmw%5F6f734774-5538-44ff-ad05-7e744f97893a)) computes the ReLU activation of the input X by applying a threshold operation. All values in X that are less than zero are set to zero.

example

Examples

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Create a formatted dlarray object containing a batch of 128 28-by-28 images with 3 channels. Specify the format 'SSCB' (spatial, spatial, channel, batch).

miniBatchSize = 128; inputSize = [28 28]; numChannels = 3; X = rand(inputSize(1),inputSize(2),numChannels,miniBatchSize); X = dlarray(X,"SSCB");

View the size and format of the input data.

Apply the ReLU operation using the relu function.

View the size and format of the output.

Output Arguments

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ReLU activations, returned as a dlarray. The outputY has the same underlying data type as the inputX.

If the input data X is a formatted dlarray,Y has the same dimension format as X. If the input data is not a formatted dlarray, Y is an unformatted dlarray with the same dimension order as the input data.

Extended Capabilities

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The relu function supports GPU array input with these usage notes and limitations:

• When the input argument X is a dlarray with underlying data of type gpuArray, this function runs on the GPU.

For more information, see Run MATLAB Functions on a GPU (Parallel Computing Toolbox).

Version History

Introduced in R2019b