RE: [ferret_users] saving from a descriptor file

[Jaclyn Brown <jaclyn.brown@xxxxxxxx>]

Thanks Jaison,
I have to save the data one time step at a time because it is so large. So
doing save/file=u_1949.nc/append uvel won't work.
Also the L='L' returned an error.

I tried defining the time axis again (define axis/t=..), and assigning it to
the variable (u=uvel[gt=taxis@asn]) even though this seems to be redundant.
Nevertheless it did the trick. No idea why. I think there must be some
problem with my descriptor file that I can't see. 

I made the descriptor with make_des.pl one_file.nc>collated_files.des and
then added the extra files by typing in extra stepfile_records. I did this
because the descriptor file wouldn't join the files together automatically.
I guess this is where some error has been introduced.

Cheers,
Jaci 

-----Original Message-----
From: Jaison Kurian [mailto:jaison@caos.iisc.ernet.in] 
Sent: Monday, November 06, 2006 1:22 PM
To: Jaclyn Brown
Cc: ferret_users@noaa.gov
Subject: Re: [ferret_users] saving from a descriptor file

Hi Jaclyn,
           If you want to write the data for l=1:122, there is
no need to open the output file with /LLIMITS qualifier. Just
go like this :

  use "/kuroshio/jb842/POP/ful.....
  set reg/l=1:122
  save/fie=u_1949.nc uvel

That is all ! 

In your method, The following line is fine

   save/file=u_1949.nc/clobber/llimits=1:122/l=1 uvel

I think the next line should be

   repeat/l=2:122 (save/file=u_1949.nc/L=`L`/append uvel)

Because, each time you have to specify the L index or indices
that you are appending to the file opened with /LLIMITS. This
method is used only if there is a basic difference between the 
time axis of source data and that of the final output one or 
say you want to do some processing only for a give period. In
normal case "set reg" or specifying region as 
"save/L=1:122/file=somefile.nc/append uvel" will work just fine.

Hope this helps,

Jaison 

On Mon, 6 Nov 2006, Jaclyn Brown wrote:

> 
> Hi,
> I am trying to save a subset of a descriptor file I created. When I open
the
> descriptor file in ferret the time axis is as it should be. When I save
some
> of it (see below) the new file does not have the correct time axis. Every
> point has the same time 2-Jan-1949, which is the first time step. 
> Any ideas where I am going wrong?
> Cheers,
> Jaci
> 
> 
> use "/kuroshio/jb842/POP/full_output_July2006/Pacific1949.des" !reads in
> datafiles
> 
> save/file=u_1949.nc/clobber/llimits=1:122/l=1 uvel
> repeat/l=2:122 (save/file=u_1949.nc/append uvel)
> 
> 
>