Add string files to a cell array within a loop

Hi!!

I am creating a preprocessing fmri pipeline and wanted to ge the names of all the files from each run of a subject in a cell array. So if the subject did 3 runs I would have a 1x3 cell array where each cell would correspond to a run.

I am getting the files names in the following loop:

user = 'user';

subjects = [1]; % Replace with a list of all of the subjects you wish to analyze

runs = [1 2 3];

for subject=subjects

runFiles = cell(1,length(runs));

for run = runs

subject = num2str(subject,'%02d');

run = num2str(run);

fileName = ['C:\Users\',user,'\Documents\BIDS__dataset\sub-',subject,'\ses-01\func\sub-PL',subject,'_ses-01_task-01_run-',run,'_bold.nii'];

runFiles(run) = fileName;

end

end

But when I try to add the file name to the cell array I get the error "Conversion to cell from char is not possible."

I tried to to

runFiles(run) = cellstr(fileName); 

and

runFiles{run} = fileName; 

but I end up with a 1x51 cell array instead of a 1x3.

For reference, I would like to end up with something like:

{

{'C:\Users\user\Documents\BIDS__dataset\sub-PL01\ses-01\func\sub-01_ses-01_task-01_run-1_bold.nii'}

{'C:\Users\user\Documents\BIDS__dataset\sub-01\ses-01\func\sub-01_ses-01_task-01_run-2_bold.nii'}

{'C:\Users\user\Documents\BIDS__dataset\sub-01\ses-01\func\sub-01_ses-01_task-01_run-3_bold.nii'}

};

Thank you in advance!

Answer 1

[Stephen23]

Simpler using COMPOSE():

user = 'user';
runs = [1,2,3];
subj = 1;
fmt = 'C:\\Users\\%s\\Documents\\BIDS__dataset\\sub-%02d\\ses-01\\func\\sub-PL%02d_ses-01_task-01_run-%d_bold.nii';
txt = compose(fmt,user,subj,subj,runs(:))

txt = 3×1 cell array
    {'C:\Users\user\Documents\BIDS__dataset\sub-01\ses-01\func\sub-PL01_ses-01_task-01_run-1_bold.nii'}
    {'C:\Users\user\Documents\BIDS__dataset\sub-01\ses-01\func\sub-PL01_ses-01_task-01_run-2_bold.nii'}
    {'C:\Users\user\Documents\BIDS__dataset\sub-01\ses-01\func\sub-PL01_ses-01_task-01_run-3_bold.nii'}