MinLength in the sequenceInputLayer and SignalLength in cwtLayer

How to set the parameter MinLength in the sequenceInputLayer and SignalLength in cwtLayer. Knowing that I'm working on a sequence classifier and the train data is in the form of a cell array with the size of num_sequencies*1 and each sequence is a matrix of 62*800 (62 is the number of channels or features)

XTrain{1} = rand(62, 800);
numChannels = 62;
net [ sequenceInputLayer(numChannels,"MinLength",800,"Name","input"), ...
      cwtLayer("SignalLength",200,"IncludeLowpass",true,"Wavelet","amor")];

[Ahmed]

What are the ranges for MinLength and SignalLength that I can use, And How it can affect results?

Answer 1

[Rahul]

Hi @Ahmed,

As per my understanding, you wish to know viable ranges of 'MinLength' and 'SignalLength' properties which are required to be set in the 'sequenceInputLayer' and 'cwtLayer' functions respectively.

After reviewing the documentations for 'sequenceInputLayer' and 'cwtLayer' functions, the section for required properties suggest the following:

• 'MinLength' (sequenceInputLayer): "When training or making predictions with the network, if the input data has fewer than 'MinLength' time steps, then the software throws an error". "To check that a network supports propagating your training and expected prediction data, set the 'Minlength' property to a value less than or equal to the minimum length of your data and the expected minimum length of your prediction data".

• 'SignalLength' (cwtLayer): This property is specified as a positive integer greater than or equal to 4. This property can only be set at the time of creation, and is read-only after the object gets created.

The folloewing MATLAB Answer can be referred:

https://www.mathworks.com/matlabcentral/answers/2079936-what-means-minlength-in-sequenceinputlayer

The following MathWorks documentations can be referred:

'MinLength' (sequenceInputLayer): https://www.mathworks.com/help/releases/R2024a/wavelet/ref/cwtlayer.html

'SignalLength' (cwtLayer): https://www.mathworks.com/help/releases/R2024a/deeplearning/ref/nnet.cnn.layer.sequenceinputlayer.html

Thanks.