minibatchqueue function cannot generate the expected MiniBatchSize

As the title states, when I am using minibatchqueue, the data generated is not the batch size I specified, but the full batch.

Here's a very simple code to illustrate the problem:

t_list = dlarray(0:0.001:2,'CB');
mbq = minibatchqueue( ...
    arrayDatastore(t_list), ...
    MiniBatchFormat='CB',...
    MiniBatchSize=200, ...
    OutputEnvironment='auto');
next(mbq);

Running this code reveals two things that are not as expected:

I don't know what the problem is. Thanks to the technician for paying attention and giving an answer!

Answer 1

[Joss Knight]

You've asked your arrayDatastore to iterate over the rows because that's the default. So as far as arrayDatastore is concerned, you have one row, therefore the maximum number of times you can call read() is 1. Therefore minibatchqueue truncates the MiniBatchSize to 1 because you only have 1 observation.

If you want arrayDatastore to iterate over the columns you need to specify an IterationDimension of 2.

[Li Ea]

Thank you very much for your answer, my puzzle was solved perfectly!