CDO

Hi,

is there a way to do this for a series of files with an increment different from 1 (say, ifile1980 ifile1985 ifile1990)?

There is no "increment" - CDO only look for all the files which has the suffix (or file name/extension which contains ...) between 1-6. For example, say you do not have ifile4, "cdo -ensmean ifile[1-6] ofile" calculates the ensemble mean of the rest of the input files. so if you would like to calculate the "ensmean" of ifile1980 ifile1985 ifile1990 - you could try:

cdo -ensmean ifile19[8-9][0-5] ofile

the "[8-9]" look for the appropriate file extension which contains digits 8 to 9; same is the case for [0-5]

Second, is there a simple way to make a filename substitution for a series of files that do not always contain the same number of digits. I.e. is there a shorthand way to call the following:
cdo ensmean ifile1 ifile2 ifile3 ifile4 ifile5 ifile6 ifile7 ifile8 ifile9 ifile10 ofile

The answer is similar BUT it would be better if you could rename your files (may be with linux "rename") such that the file names have equal number of "digits"; ie, renname ifile1 to ifile01, and ifile9 to ifile09, then you can try: cdo -ensmean ifile[0-9][0-9] ofile

or say if you have 48 files (ifile001 .. ifile048): cdo -ensmean ifile0[0-4][0-9] ofile

Hope this helps!

Cheers,
J.

File Name Substitution is a powerful Shell feature and not part of CDO.

Short command for:

cdo ensmean ifile1 ifile2 ifile3 ifile4 ifile5 ifile6 ifile7 ifile8 ifile9 ifile10 ofile

could be:

cdo ensmean ifile* ofile

But this will use all files starting with ifile and the order could be changed. You can check it with the UNIX command ls:

ls ifile*
ifile1  ifile10 ifile2  ifile3  ifile4  ifile5  ifile6  ifile7  ifile8  ifile9

The order of the input files doesn't matter for ensmean. But it is very important for the CDO operators copy, cat and mergetime. Therefore it is a good praxis to name/rename your files in a way that there are alphanumerically sorted.

Here is a table of the basic Pattern-Matching Characters:

?	match any single character
*	match zero or more characters, including null
[abc]	match any character or characters between the brackets
[x?/span>z]	match any character or characters in the range x to z
[a?/span>ce?/span>g]	match any character or characters in the range a to c, e to g
[!abc]	match any character or characters not between the brackets
[!x ?/span>z]	match any character or characters not in the range x to z

The answer is similar BUT it would be better if you could rename your files (may be with linux "rename") such that the file names have equal number of "digits"; ie, renname ifile1 to ifile01, and ifile9 to ifile09, then you can try: cdo -ensmean ifile[0-9][0-9] ofile

I'm working with a fairly large amount of CMIP5-format data, which uses 'r1', 'r2' ... 'r10' in the filename (and directory structure) to indicate different realizations, so I am not keen to start changing filenames. However, I think by using BASH variables I should be able to resolve my issue.

Thanks for the help!