Loop filename substitution i.e. loop for Year2002_month01.nc for varying year and month.

Can anyone help me with this, I have created a script in MatLab which will process a set of data for me in a specific way and produce output images. I've been able to run simple loops for values but I have never carried out a similar process for varying input filenames.

I'm wondering whether it is possible to do a substitution style loop to run the script on a large amount of files based on the start filename.

Say for example I had the following files: - year01_month01 - year01_month02 - ... - year02_month01 - ..

I want the loop to loop for all the month files for year 1 then go on to year 2, until all files in the directory are processed, or alternatively I could set the final year and month. I saw a similar substitution done using a method similar to for year??_month?? in UNIX, but I would need it for both variables and likewise to work in MatLab.

Hope someone can help.

Answer 1

[Walter Roberson]

http://matlab.wikia.com/wiki/FAQ#How_can_I_process_a_sequence_of_files.3F

Is the 'month01' intended to be literally the word 'month' followed by a two-digit month number in the year, or is it intended to be a month name? If it is the literal word 'month' etc., then sort() applied to the filenames should work well to get the right order; if it is a month name, then a month-name sort takes a slight bit more code (and the easiest way to do that might be by a datenum() conversion)

[Joshua]

N01_1996m01T_shelf_n3.nc <--that's an example filename, the variables are the year which is in this case 1996, and the month, which is in this case 01.

I basically need it to run for years between 1993 and 2007 and months from 01 to 12. Does that make sense?

[Walter Roberson]

dirinfo = dir('N01*.nc');
filedates = regexprep({dirinfo.filename}, '^....(\d\d\d\d).(\d\d).*$', '$1$2');
[sorteddates, sortidx] = sort(filedates);
dirinfo = dirinfo(sortidx);  %and then it will be in sorted order

Now

for K = 1 : length(dirinfo)
  thisfile = dirinfo(K).filename;
  Process file "thisfile"
end