Shell Programming and Scripting

Hi all, I am trying to make a for loop invoking files with different extensions (*.ugrd and *.vgrd) and I cant just make it work. Cant figure out how to load the files so as to use them in subsequent commands like the ones in this pseudo code. the files are arranged such that in one date for instance, it has both a .ugrd and .vgrd, that is, 19990101.ugrd; 19990101.vgrd; 19990102.ugrd; 19990102.vgrd and so on

Code:

for i in *.ugrd
    do take the sqrt of the 19990101.ugrd  > $i.txt
for j in *.vgrd
    do take the sqrt of the 19990101.vgrd > $j.txt
         take the sum of the $i.txt $j.txt > $j.xyz
      done
done

taking the sum part doesn't call the right pair of the file.
any help would be greatly appreciated. many thanks.

What does the content of .ugrd and .vgrd files look like?

.ugrd and .vgrd are one column files of values. thanks,.

Code:

19990101.ugrd
23.523
1.2450
1.5210
1.9073

Ok, so what needs to happen with the content of ugrd and vgrd ?

First , I want to take the sqrt of the contents of each file for both .ugrd and .vgrd and then take the sum of the pair of corresponding files. Thanks.

Hi ida1215,

I see 4 lines per file. What do you mean with "take the sqrt of the contents of each file" and what do you mean with "take the sum of the pair of corresponding files" ?

We cannot do this:

Code:

√"19990101.ugrd"

and we cannot do this:

Code:

19990101.ugrd + 19990101.vgrd

Hi, am sorry for explaining poorly. I think my problem is on the calling of files to perform the calculations. like for instance, I would tell the loop that it will load the specific files for time-step 1 and so on. something like:

Code:

for files in u.grd and v.grd
    do 19990101u.grd + 19990101v.grd =19990101.grd
       19990102u.grd + 19990101v.grd =19990102.grd
       19990103u.grd + 19990103v.grd =19990103.grd
       and so on ...
done

How do I load these 2 file types in a loop so that I can use them both for the calculation. Thanks much.