MATLAB: Files directory not found

dirguinotfound

GoodMorning, I ust want torun a script where it could give a value of zero if the selected directory doesn't exist.

It could be:

if dir C:\a == 'not found'
    B=0
else
    B=1
end

Actually i wanted an errormessage tho show up in gui, but that I can do by myself. Thanks

Best Answer

Use exist:

if exist('C:\a', 'dir')

Related Solutions

MATLAB: ‘exist’ function returning false positive for directory.

Since R2017b the command isfolder is available and safer than exist('dir').

A problem of your approach is the usage of relative path names. Remember that a GUI or TIMER callback can change the current directory unexpectedly. In parallel programming this is a common problem also. So the solution is easy: Never work with relative paths.

A clean version:

base = 'C:\';
mkdir(fullfile(base, 'a', 'b', 'c');
want = 'C:/a/b/c';
isfolder(fullfile(want, 'b\c'))  % FALSE

isfolder(fullfile(base, 'b\c'))  % FALSE

Note, that any crazy callback cannot cofuse this by changing the current directory.

If do not understand, why exist('b/c','dir') returns 7, if the current folder is C:\a\b\c . Maybe b\c is existing anywhere in Matlab's path ? Remember that exist checks the complete path.

By the way, why do you assume, that

mkdir a; cd a

creates 'C:\a' and not the directory 'C:\a; cd a'

? It works as you expect it, but I do not know, where this is documented.

MATLAB: Error that file not found

Please attach 'csvfilelistohm.txt'. Apparently there is a string in there that is a filename but without an extension. This code is not robust at all. But what is worse is that the name variable will not change on each iteration - not that it has to since you could overwrite "name" but it should be different. If you don't need to store all the names (or the only one that you are reading actually), then just overwrite it:

for k = 1 : num_files % Don't use i as an iterator variable.
    % Get a new filename from the file.  (Won't happen though!)
    thisFileName = fscanf(fileID,'%s\n',1);
    % It's presumably a csv file, so check if it's actually there.
    [folder, baseFileName, extension] = fileparts(thisFileName);
    if ~exist(thisFileName)
        warningMessage = sprintf('WARNING: file does not exist:\n%s', thisFileName);
        uiwait(warndlg(warningMessage));
        continue;
    end
    % If we get to here, the file exists.
    % Make sure it's a CSV file.
    if ~strcmpi(extension, '.csv')
        continue;
    end
    % Read file into an array.
    mydata = csvread(thisFileName,12,1,[12,1,61,17]);
    % Now do something with mydata.
end

Best Answer

Related Solutions

MATLAB: ‘exist’ function returning false positive for directory.

MATLAB: Error that file not found

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