Sorting files in struct according to time in filename

Hello,

I have jpg images with names:

t_=_15_s.jpg

t_=_30_s.jpg

...

t_=_900_s.jpg

and I read them using dir(*.jpg) command. Unfortunatelly, they are sorted wrongly (they start with t_=_105_s.jpg), and I would like to correct it.

I would like to ask you for help.

BR

Mathew

[the cyclist]

It would be much easier to help if you uploaded your data, or a small representative sample. You can use the paper clip icon in the INSERT section of the toolbar.

[Dyuman Joshi]

Use https://in.mathworks.com/matlabcentral/fileexchange/47434-natural-order-filename-sort?s_tid=prof_contriblnk on the names.

[Mathew Smith]

The cyclist: I have uploaded images with the numbers to the original question so you can try.

Answer 1

[Stephen23]

You could download my FEX submission NATSORTFILES():

https://www.mathworks.com/matlabcentral/fileexchange/47434-natural-order-filename-sort

And use it like this:

S = dir('*.jpg');
S = natsortfiles(S);

Or use sufficient leading zeros in the filenames.

[Mathew Smith]

Hello Stephen23, I can't install these extensions to my Matlab, but thank you for help.

[Dyuman Joshi]

You don't need to install it.

You just need to add all the contents to the current directory, or add them to the path of MATLAB - https://in.mathworks.com/help/matlab/matlab_env/add-remove-or-reorder-folders-on-the-search-path.html

[Voss]

If you can't use natsortfiles, here is an alternative:

unzip images

S = dir('*.jpg');

The original order:

{S.name}.'

ans = 22x1 cell array
    {'images_105.jpg'}
    {'images_120.jpg'}
    {'images_135.jpg'}
    {'images_15.jpg' }
    {'images_150.jpg'}
    {'images_165.jpg'}
    {'images_180.jpg'}
    {'images_195.jpg'}
    {'images_210.jpg'}
    {'images_225.jpg'}
    {'images_240.jpg'}
    {'images_255.jpg'}
    {'images_270.jpg'}
    {'images_285.jpg'}
    {'images_30.jpg' }
    {'images_300.jpg'}
    {'images_315.jpg'}
    {'images_330.jpg'}
    {'images_45.jpg' }
    {'images_60.jpg' }
    {'images_75.jpg' }
    {'images_90.jpg' }

Sort:

[~,idx] = sort(str2double(regexp({S.name},'\d+','match','once')));
S = S(idx);

Now they are sorted:

{S.name}.'

ans = 22x1 cell array
    {'images_15.jpg' }
    {'images_30.jpg' }
    {'images_45.jpg' }
    {'images_60.jpg' }
    {'images_75.jpg' }
    {'images_90.jpg' }
    {'images_105.jpg'}
    {'images_120.jpg'}
    {'images_135.jpg'}
    {'images_150.jpg'}
    {'images_165.jpg'}
    {'images_180.jpg'}
    {'images_195.jpg'}
    {'images_210.jpg'}
    {'images_225.jpg'}
    {'images_240.jpg'}
    {'images_255.jpg'}
    {'images_270.jpg'}
    {'images_285.jpg'}
    {'images_300.jpg'}
    {'images_315.jpg'}
    {'images_330.jpg'}

[Stephen23]

"I can't install these extensions to my Matlab, but thank you for help."

MATLAB files do not need to be installed: if you can write your own file then you can use this code too.

Just unzip the ZIP-file into the current directory and use it.