MATLAB: Problem with “change directory” in a for loop

cannot cdcdchange directoryfor loop

I'm having a problem with "cd" when looping through folders. Below is the problematic part of my script:

datadir='wherethedatais';
cd(datadir);
dirlist=dir('sub*');   % list of different subjects
for h=1:length(dirlist)
cd(dirlist(h).name)

Everything is fine until the 7th iteration of the loop when I get this error:

Error using cd
Cannot CD to sub0010 (Name is nonexistent or not a directory).

All the folders are named subXXXX where XXXX is 0001 to 0114.

Any ideas what might be causing this?

Best Answer

Using cd just to read data is error prone. Because you have to ensure that after cd to change back to your original dir, otherwise the next dir will not be found. So if you first change to sub001, then the next change to sub002 will work from within sub001, i.e., tries to change to sub001/sub002 with respect to your original dir.

Instead of cd, use something like

filename = fullfile(dirlist(h).name, 'data.mat')); %assuming 'data.mat' is the name of your mat-file in the various subdirectories
load(filename, 'X'); % assuming 'X' is the variable you need from file data.mat

Related Solutions

MATLAB: Removing a folder from a directory outsaide the current directory of Matlab

You just need to specify the full path of the folder you want to delete to rmdir. If you supply just the folder name, it assumes that folder is in the current directory. You can use fullfile to build the full path of the folder:

parentfolder = 'C:\somewhere\on\the\drive';
foldername = 'deleteme'
rmdir(fullfile(parentfolder, foldername), 's');

MATLAB: Folder in a directory

A = dir % you get everything in current directly of matlab.  or if you want to explicitly mention any directory path then you can do it like this.
A = dir('/yourpath');

now A has all files and directories. So you can access by loop

A(1).name

to get only Directory indexes you can do following code.

myDir = find(vertcat(A.isdir));

now myDir has indexes of directory(folders only).

to print the name of directory to confirm, you can do it like this.

A(myDir).name

where first two are only the pointers. you can always start your loop from 3. Ignore first two indexes.

Best Answer

Related Solutions

MATLAB: Removing a folder from a directory outsaide the current directory of Matlab

MATLAB: Folder in a directory

Related Question