I have a double for loop in Matlab. The first loop determines the working directory. The second loop determines the name of the file in the working directory that I want to load and work with:

for j=1:J

    cd / users/M_%j/    %************

    A_temp=cell(I,1);
    for ii=1:I
        if isfile(['A.' num2str(ii) '.mat'])
        load(['A.' num2str(ii) '.mat']);
        A_temp{ii}= A;
        end
    end


    A_final_x%j= vertcat(A_temp{:});         %************

    cd /users/

    save('A_final_x%j.mat', 'A_final_x%j')   %************
end

I don't know how to correctly replace the %j that you see in the three lines of my code highlighted by %************. Could you advise on how to proceed?

CodePudding user response：

I'm turning my comment into an answer... please see the code comments below which address why I've changed your code at each step

for j = 1:J
    % Create the file path
    fp = ['/users/M_', num2str(j)]; % Alternative: fp = sprintf('/users/M_%d', j );
    
    A_temp=cell(I,1);
    for ii = 1:I
        % Create a full path reference to the mat file
        filepath = fullfile( fp, ['A.' num2str(ii) '.mat'] );
        if exist( filepath, 'file' ) % exist is more flexible than "isfile"
            % Directly assign to a variable, will error if "A" isn't in the mat file
            % which is more robust than not knowing if you had a bad file
            A = getfield( load( filepath ), 'A' ); 
            A_temp{ii}= A;
        end
    end

    A_final_x = vertcat(A_temp{:}); % No need for a dynamic variable name

    % Define the output path
    outpath = fullfile( fp, ['A_final_x' num2str(j) '.mat'] );
    save( outpath, 'A_final_x' ); % save using the full path and a fixed var name
end