Saving mat file with prefix over loop

Hello,

Looking help in saving same .mat file with prefix over loop.

Facing error with following script:

clear all
close all
d = uigetdir();
filePattern = fullfile(d, '*.mat');
file = dir(filePattern);
for k = 1: numel(file)
    baseFileName = file(k).name;
    fullFileName = fullfile(d, baseFileName);
    % my code here
    outputBaseFileName = sprintf('Edited_%s', baseFileName);
    outputFullFileName = fullfile(file(k).folder, outputBaseFileName);
    save(outputFullFileName,'Variable_1','-append');
end

Error I am getting is:

Error using save
Unable to write file 'myPath\Edited_myFileName.mat'
No such file or directory.

Error in Untitled (line 29)
save(outputFullFileName,'Variable_1','-append');

[Walter Roberson]

    outputFullFileName = fullfile(file(k).folder,, outputBaseFileName);

is not valid syntax: it has two commas in a row.

Did the error message literally give the path starting with myPath\ or did you edit that for posting purposes?

[adi kul]

Fixed it. thanks.

But facing same error!

[Stephen Cobeldick]

It looks like you are actually using code from your earlier question:

https://www.mathworks.com/matlabcentral/answers/493728-loop-over-subfolders-and-saving-cat-parameters

You need to define D as an existing absolute path or relative path, instead of using the literal text 'mypath' (which apparently does not exist).

https://www.mathworks.com/help/matlab/matlab_env/specify-file-names.html

https://blogs.mathworks.com/pick/2011/04/01/be-absolute-about-your-relative-path-with-getfullpath/

[adi kul]

nope. This is different code.

The "myPath" is just an example. actual path is C:\... something like this

[Stephane]

You can cerate a dummy text file where you want to save your files, then compare its path+name to the output of outputFullFileName

[adi kul]

Thing is if I use fullFileName instead of outputFullFilename it indeed saves same file with added variable.

    % outputBaseFileName = sprintf('Edited_%s', baseFileName);
    % outputFullFileName = fullfile(file(k).folder, outputBaseFileName);
    save(fullFileName,'Variable_1','-append');

I am not sure what's wrong in here. Here is the full code here:

clear all
close all
d = uigetdir();
filePattern = fullfile(d, '*.mat');
file = dir(filePattern);
for k = 1: numel(file)
    baseFileName = file(k).name;
    fullFileName = fullfile(d, baseFileName);
    x=load(fullFileName)
    Variable_1=x.Variable_4./x.Varibale_5;
    outputBaseFileName = sprintf('Edited_%s', baseFileName);
    outputFullFileName = fullfile(file(k).folder, outputBaseFileName);
    save(outputFullFileName,'Variable_1','-append');
end

Answer 1

[Walter Roberson]

clear all
close all
d = uigetdir();
filePattern = fullfile(d, '*.mat');
file = dir(filePattern);
for k = 1: numel(file)
    baseFileName = file(k).name;
    fullFileName = fullfile(d, baseFileName);
    x=load(fullFileName)
    x.Variable_1 = x.Variable_4./x.Varibale_5;
    outputBaseFileName = sprintf('Edited_%s', baseFileName);
    outputFullFileName = fullfile(file(k).folder, outputBaseFileName);
    save(outputFullFileName, '-struct', 'x');
end

Answer 2

[Ruger28]

Your Edited .mat file does not exist, so you must create it. Check to see if it exists, if it does, append. If it does not, create it.

clear all
close all
d = uigetdir();
filePattern = fullfile(d, '*.mat');
file = dir(filePattern);
for k = 1: numel(file)
    % my code here
    outputFullFileName = fullfile(file(k).folder,sprintf('Edited_%s', file(k).name));
    if exist(outputFullFileName,'file') % file exists
        save(outputFullFileName,'Variable_1','-append');
    else % file is new since you made it "edited", and needs created
        save(outputFullFileName,'Variable_1');
    end
end

[adi kul]

this creates Edited_ .mat file but with only Variable_1 in it. While I want to have all the other variables from oriniglal .mat file and apend with Variable_1