How to use imageDatastore function to train model on .mat file dataset?

I have dataset of [2PSK,8PSK,4PSK] and its size is [2,1280,2]. I have change the input layer of the model but when i run following code i got error

miniBatchSize = 128;
valFrequency = floor(numel(auimdsTrain.Files)/miniBatchSize);
checkpointPath = pwd;
options = trainingOptions('sgdm', ...
    'MiniBatchSize',miniBatchSize, ...
    'MaxEpochs',100, ...
    'InitialLearnRate',1e-3, ...
    'Shuffle','every-epoch', ...
    'ValidationData',valauimds, ...
    'ValidationFrequency',valFrequency, ...
    'Verbose',false, ...
    'Plots','training-progress', ...
    'CheckpointPath',checkpointPath);

error:

Error using nnet.cnn.TrainingOptionsSGDM (line 117)

The value of 'ValidationData' is invalid. Unable to read file:

'D:\data-11\TIME-IQ\128APSK\frame_snr30iq_128APSK_1008.mat'.

Error in trainingOptions (line 315)

opts = nnet.cnn.TrainingOptionsSGDM(varargin{:});

Caused by:

Error using matlab.io.datastore.exceptions.decorateCustomFunctionError>generateReadFcnError (line 103)

Error using ReadFcn @readDatastoreImage for file:

D:\data-11\TIME-IQ\128APSK\frame_snr30iq_128APSK_1008.mat

Error using imread>get_format_info (line 545)

Unable to determine the file format.

Error in imread (line 391)

fmt_s = get_format_info(fullname);

Error in readDatastoreImage (line 12)

data = imread(filename);

Answer 1

[Sudharsana Iyengar]

General Tutorial:

https://in.mathworks.com/matlabcentral/fileexchange/99779-neural-network-and-knn-algorithm-tutorial-with-matlab?s_tid=prof_contriblnk

I will give you the code of image datastore

imds =imageDatastore('trainingset','IncludeSubfolders', true,...
      'LabelSource','foldernames');