How to save a variable in the same mat.file each time a function runs?

I have a matlab function which runs in combination with BCI2000. I want to save a variable each time the function re-runs to do the calculations for the BCI server (real-time monitoring).

I tried something like this:

pp = 1;  %begin point

variab= [];
for i= 1:1000
  np(i) = pp + size(out_signal(i),1)-1; %next point
variable_new = [out_signal]

   variab = [variab variable_new];
    %variable(i) = [pp,];  % X moet je nog even bedenken hoe dat zit met variabelen/cells etc.  
                           %(pp:np,:) voor size(A,2)>1
    pp = np +1;

    end

    save ('variable.mat','variab')

This does not work. How can I save the outcome signal each time the function runs?

[Stephen23]

The easiest way would be to use matfile. Then you can simply access the variable in the .mat file by using indexing.

Whatever you do, do NOT try to create numbered variables: creating or accessing numbered variables makes slow, buggy, and obfuscated code:

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

Answer 1

[KSSV]

Go through the link: https://in.mathworks.com/matlabcentral/answers/33113-append-save-same-variable-with-updated-values-into-mat-file-row-wise