How do I create a mat file in a loop and store a matrix generated in that newly created mat file? (i also need to save every created mat file in the loop)

I tried with the following code but it says

for j=0:0
    for k=0:1
        filename=sprintf('%d%d.wav',j,k);
        sin_of_sin=audioread(filename);
        [st_matrix] = st_temp(sin_of_sin);  % st_temp is my function file which returns the generated matrix
        sprintf('angry_%d%d.mat',j,k)=st_matrix;
     end
end

Error message:

Subscript indices must either be real positive integers or logicals.

[Jan]

Please post the complete error message, because it will tell us in which line the problem occurs.

[sangeet sagar]

Subscript indices must either be real positive integers or logicals.

Error in stransform (line 14)
        sprintf('angry_%d%d.mat',j,k)=st_matrix(:,1:50);

Answer 1

[Image Analyst]

Instead of assigning a matrix to the sprintf() function, which of course you cannot do,

sprintf('angry_%d%d.mat',j,k)=st_matrix;  % Bad syntax!!!

try this:

matFileName = fullfile(pwd, sprintf('angry_%d%d.mat',j,k));
save(matFilename, 'st_matrix');

[sangeet sagar]

this seems incorrect

   save(matFilename, 'st_matrix');

I need to save the file name as my newly generated mat file. For example: for first iteration it should save as

angry_00.mat

then in second iteration it should save as

angry_01.mat

[Image Analyst]

It will make those files. Variables to save are listed in single quotes. Each file will have the current verions/copy of st_matrix stored inside of it. If you also want to save the filename itself inside of the mat file, you can add it:

save(matFilename, 'st_matrix', 'matFilename');

[sangeet sagar]

Thank you.Worked like a charm

Answer 2

[Jan]

sprintf('angry_%d%d.mat',j,k)=st_matrix;

This cannot work. On the left you create a char vector, not a variable. In addition there is no need to create a variable dynamically only to create a MAT file. See also: Tutorial: Why to avoid to create variables dynamically.

If you want to create a MAT file, use save:

FileName = sprintf('angry_%d%d.mat',j,k);
save(FileName, 'st_matrix');

[sangeet sagar]

Can you please tell, why did you write 'st_matrix' here.

save(FileName, 'st_matrix');

I need to save the filename in every iteration. For example in first iteration- angry_00.mat, then in second iteration angry_01.mat and so on.

[sangeet sagar]

Thank you Sir .Worked like a charm