Training LTSM network error in command window

'Invalid training data. Responses must be a vector of categorical responses, or a cell array of categorical response

sequences.'

Hello I am currently training a LTSM classifaction network, in which i keep coming into this same error line. I have two data types. Firstly, my xtrain is a cell array of (3 x 900 double) whilst my ytrain is a cell array with categorical vectors( 3x 900 categorical). I am running this code to provide me a netowrk which will window temproal data of the sensor readings. I initally suspected that the error was due to my ytrain, in which i have countlessly spent time to change this data type to get desired result. Could this error be po potentially an error with my xtrain?

[net] = trainNetwork(xtrain,ytrain,layers,options);

numFeatures = 1;

numHiddenUnits = 200;

numClasses = 3;

trainFcn = 'trainscg'; % Scaled conjugate gradient backpropagation.

layers = [ ...

sequenceInputLayer(numFeatures)

lstmLayer(numHiddenUnits,'OutputMode','sequence')

fullyConnectedLayer(numClasses)

softmaxLayer

classificationLayer];

options = trainingOptions('adam', ...

'MaxEpochs',250, ...

'GradientThreshold',1, ...

'InitialLearnRate',0.005, ...

'LearnRateSchedule','piecewise', ...

'LearnRateDropPeriod',125, ...

'LearnRateDropFactor',0.2, ...

'Verbose',0, ...

'Plots','training-progress');

%'MaxEpochs',60, ...

%'GradientThreshold',2, ...

%'Verbose',0, ...

%'Plots','training-progress');

%ytrain=categorical(ytrain);

%ytrain = transform(ytrain,@(data) padSequence(data,sequenceLength));

[net] = trainNetwork(xtrain,ytrain,layers,options);

%net = trainNetwork(xtrain,Ytrain,layers,options);

t_training=t_training+toc;

Answer 1

[Rishik Ramena]

You probably need to convert the ytrain to categorical while passing to trainNetwork.

ytrain=categorical(ytrain);
[net] = trainNetwork(xtrain,ytrain,layers,options);