How to split a [30x250x1000] array into 1,000-2D matrices

Hello everyone,

I have a dataset of size 30x250x100. I need to feed this array into a function 1,000 times. This is the for loop that I am using for the job. Where data_class will be the 30x250x1000 input array and number_epoch 1000.

Here i am trying to create 1,000 epoch_seg variables. Each one with 30 by 250 matrices given the 1,000 but can't figure out how to update epoch_seg to contain each matrix for every time step.

function epoch = matrix_extractor(data_class,number_epochs)

data_class;

for k=1:number_epochs

epoch(:,:)=data_class(:,:,k);

epoch_seg[k]=epoch(:,:)

end;

end

Thank you!

[madhan ravi]

Is it okay to store those 3D matrices into a 1 by 1000 cell array?

[Stephen23]

"Here i am trying to create 1,000 epoch_seg variables."

Dynamically creating or accessing variable names is one way that beginners force themselves into writing slow, complex, obfuscated, buggy code that is hard to debug. Read this to know some of the reasons why:

https://www.mathworks.com/matlabcentral/answers/304528-tutorial-why-variables-should-not-be-named-dynamically-eval

Instead of forcing yourself inrto writing inefficient, complex code, you should just use indexing. Indexing Is neat, simple, and very efficient. Unlike what you are trying to do.

[Kevin Brinneman]

Sure, will read the document. Thanks

Answer 1

[Stephen23]

Just use a simple cell array:

function epoch = matrix_extractor(data_class,number_epochs)
    data_class;
    C = cell(1,number_epochs);
    for k = 1:number_epochs
        C{k} = data_class(:,:,k);
    end
end

Note that writing this is a waste of time: just use num2cell or mat2cell.

Note that there is likely little point to this anyway: it would be simpler to just access the original data array using indexing, rather than splitting up and duplicating that data in memory. Splitting up data rarely makes processing data easier.

[Kevin Brinneman]

Yes I had the intention to just access the data but couldnt find a better way. Thanks for the help!