Re: How to handle the mean of multiple files

[John Donners <donners@xxxxxxx>]

Hi,

the problem is (probably) that you can only append data to some file along
one axis, which is here the time or l axis. The solution to your problem
is to write an even easier script:

 use output.00.nc
 use output.06.nc
 use output.12.nc
 use output.18.nc
 set region/x=1:357.5/y=-90:90

 let umean=(u[d=1]+u[d=2]+u[d=3]+u[d=4])/4
 let vmean=(v[d=1]+v[d=2]+v[d=3]+v[d=4])/4
 save/file=outputmean.nc umean,vmean

Hope that helps.

With regards,

John

 On Thu, 8 Apr 2004, du hui wrote:

> Dear ferret users:
>   I have sent a email about the question to how to do the mean of the 4
> files. But I think I made a mistake.  I have re-edited my script as
> following, but it doesn't work
>
> use output.00.nc
> use output.06.nc
> use output.12.nc
> use output.18.nc
> set region/x=1:357.5/y=-90:90
>
> let umean=(u[d=1,k=1]+u[d=2,k=1]+u[d=3,k=1]+u[d=4,k=1])/4
> let vmean=(v[d=1,k=1]+v[d=2,k=1]+v[d=3,k=1]+v[d=4,k=1])/4
> repeat/l=1:731 save/file=outputmean.nc/append umean,vmean
>
> let umean=(u[d=1,k=2]+u[d=2,k=2]+u[d=3,k=2]+u[d=4,k=2])/4
> let vmean=(v[d=1,k=2]+v[d=2,k=2]+v[d=3,k=2]+v[d=4,k=2])/4
> repeat/l=1:731 save/file=outputmean.nc/append umean,vmean
>
>
> When I excuted the above script, after finishing the level 1, then the
> following messages appeared,
>
> let umean=(u[d=1,k=2]+u[d=2,k=2]+u[d=3,k=2]+u[d=4,k=2])/4
> let vmean=(v[d=1,k=2]+v[d=2,k=2]+v[d=3,k=2]+v[d=4,k=2])/4
> repeat/l=1:731 save/file=outputmean.nc/append umean,vmean
> !-> REPEAT: L=1
>  LISTing to file outputmean.nc
>  **TMAP ERR: Requested data range is outside of data set limits
>              Expected: UMEAN[K= 2 : 2 ] Found: UMEAN[K= 1 : 1 ]
> LIST/FORMAT=CDF/file=outputmean.nc/append umean,vmean
> Command file, command group, or REPEAT execution aborted
>
> What is the mistake in my script?
> Could anyone give me some hints for this problem
> Thanks a lot
>
> _________________________________________________________________
> Ãâ·ÑÏÂÔØ MSN Explorer:   http://explorer.msn.com/lccn/
>
>

------------------------------------------
John Donners
Royal Netherlands Meteorological Institute
Dept. Oceanographic Research
http://www.knmi.nl/~donners

P.O. Box 201
Wilheminalaan 10
3730 AE  De Bilt
tel. nr. : ++31 30 2206701
fax. nr. : ++31 30 2202570
-------------------------------------------------------------- 

Zie ook/see also: http://www.knmi.nl/maildisclaimer.html