I really need help about LSTM.

Hi everyone.

I have a data set of 500*8 and I have 8 features for price prediction. I used LSTM to predict the price per hour of the day (a total of 24 prices for 24 hours a day). But I do not know how much output size should be for first fullyConnectedLayer after lstmLayer. please guide me. Thankful.

This is my code:

numResponses = size(YTrain{1},1);

featureDimension = size(XTrain{1},1);

numHiddenUnits = 15;

layers = [ ...

sequenceInputLayer(featureDimension)

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

fullyConnectedLayer(?????) %%50

dropoutLayer(0.5) %%0.5

fullyConnectedLayer(numResponses)

regressionLayer];