importdata using wild cards, strings and variables in the file name?

Just moved over from Python to MATLAB and need a way to import my data using wild cards.

my files are named as such: ####x12y34.txt

where '12' and '34' would be variables and #### are other numbers which i don't care about.

Where '*' is the wild card, I have this so far, but doesn't work:

file_path = '/home/matt/Documents/MATLAB';
rows = 12
cols = 34

file_name = dir(file_path '/*x' num2str(rows) 'y' num2str(cols) '.txt'

I found someone who suggested the below code for use with a wildcard but can't get it to work on mine for some reason, names comes up as '0x0 cell'?

names = dir('C:\Users\Oleg\Desktop\Nuova cartella\PR-2230A_YYYY-MM-DD_00-08-*.csv');
names = {names.name};

Note: added in [], which seemed to remove a syntax error(?), when z is printed it displays as '{}'

names = dir([file_path '/*x' num2str(i) 'y' num2str(j) '.txt']);
z = {names.name}

Full code of what i'm currently working with below:

rows =25;
cols = 50; 
biaspoints = 512;
biasmat3up = zeros(rows,cols,biaspoints);
biasmat3down = zeros(rows,cols,biaspoints);
datamat3up = zeros(rows,cols,biaspoints);
datamat3down = zeros(rows,cols,biaspoints);
file_path = '/home/matt/Documents/MATLAB';

for i=1:rows
    for j=1:cols
        [i j]
        clear p1;
        counter = squeeze((i-1)*cols+j);

          names = dir([file_path '/*x' num2str(i) 'y' num2str(j) '.txt']);

          z = {names.name};

          z

Answer 1

[Steven Lord]

I would expect this to work:

names = dir([file_path '/*x' num2str(i) 'y' num2str(j) '.txt']);
z = {names.name}

Let's do a quick check and make sure there are some files that match your pattern in the directory.

ls(fullfile(file_path, '*.txt'))

If this says something like "*.txt not found" then the directory doesn't contain any files with the .txt extension, or MATLAB can't find the directory whose path is stored in the variable file_path. [You've expressed it as a UNIX path; are you on Mac OS X or Linux? If you're on Windows, you'll need to change file_path to be a Windows path.]

If that does show some files, let's check for those whose names contain x then y, separated by some characters.

ls(fullfile(file_path, '*x*y*.txt'))

Does that list any files? If it does, let's go the next step and write a little tweak of the command in the first code section.

filepattern = sprintf('*x%dy%d.txt', i, j) % Check that this looks like what you want
names = dir(fullfile(file_path, filepattern))

If there are files in the directory that match the pattern from the third code section above (x*y.txt) that also match the pattern stored in filepattern (*x#y#.txt where # is one- or potentially two-digit number) they should show up in the names struct array.