MATLAB: How to generate sequenced file names with file extensions

concatenationstrings

What's the best way to generate sequenced file names with file extensions. The format I'm looking for is something along the lines of 'pcimage' + '0001' + '.h5', so the resulting names would be 'pcimage001.h5', 'pcimage002.h5', …, 'pcimage2401.h5', … etc. I was trying the following code, but because the leading 0s would change between 9 and 10 it throws an error. I could see doing it with an if statement that determines the number of digits of i, but i'd prefer a more elegant solution if one exists. Thanks for any help!
for i = 1:1:10 filename(i,:) = strcat('pcimage00', num2str(i), '.h5') end

Best Answer

See the documentation for num2str to find the formatSpec input option. Then, your code simply becomes:
for i = 1:1:10
  filename(i,:) = strcat('pcimage', num2str(i,'%04d'), '.h5');
end
In R2016b and later, this can be done without the loop:
filenames = compose('pcimage%04d.h5',1:5)'; % for cellstr output
filenames = compose("pcimage%04d.h5",1:5)'; % for string output
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