Any limit to the number of files opened ?

[See Hai Ooi]

Dear Davide Sotil Bertanzetti,

     Thank you.

     As you are aware, 2004, for example, is a leap
year but 2001 is not.  If I need to open files from
year 2001(1460 time-steps) to 2004(1464 time-steps),
the few pertinent lines of the modified single data
descriptor file have to be written as

     DSET uwnd.%y4.nc
     OPTIONS template
     TDEF 5844 linear 00z1jan2001 6hr

     In other words, I need to know the number of leap
years within the required period, say, from 1986 to
2005 in order to have the right TDEF.  Also, I need to
have another single data descriptor file for
v-component wind.  Can I avoid doing all these by just
using the script that I had written in order to attain
my objective ?  If yes, how should I overcome the
error encountered ?  Hope to hear from you soon.

     Best regards.

OOI See-hai




--- Davide Sotil Bertanzetti <davide at CEAM.ES> wrote:

> Hello Ooi See Hai. I don't know if there is a limit
> on the total number of
> opened files, maybe yes, but I think there is an
> alternative way to do what
> you are purposing:
>
> You can use a single data descriptor file to
> aggregate multiple data files
> and handle them as if they were one individual file.
> You can find the
> proceadure in the GRADS User's Guide->Anlaysis
> Topics->Using Templates to
> Aggregate Data Files.
>
> Davide Sotil Bertanzetti
>
>
> On Tue, 12 Sep 2006 09:14:16 +0100, See Hai Ooi
> <axl419 at YAHOO.COM> wrote:
>
> >Dear all,
> >
> >     My intention is to open a total of 40 files
> >consisting of u- and v- component winds at 850 hPa
> >level from 1986 to 2005 in order to obtain 20-year
> >climatological pentad mean wind as shown in my
> script
> >attached.  However, on reaching file number 33, the
> >following error messages appeared :-
> >
> >   add_connect: too many connects, cannot add
> another
> >   g:\cdc\uvw\uwnd.2002.nc does not exist or is not
> a
> >netCDF file.
> >   Couldn't ingest SDF metadata
> >   .
> >   .
> >   .
> >   SET DFILE error: file 33 not open
> >   Data Request Error: File number out of range
> >       Variable = uwnd.33
> >   .
> >   .
> >   .
> >  For your information, I use window version of
> GrADS
> >V1.8SL9.  I have no problem in obtaining 10-year
> data
> >(1996-2005).
> >
> >   Can someone show me how to overcome the error ?
> >
> >   Thank you.
> >
> >Sincerely,
> >
> >Ooi See Hai
> >
> >Send instant messages to your online friends
> http://uk.messenger.yahoo.com
> >* To obtain climatological pentad mean 850 hPa
> winds
> >* by Ooi See Hai on 12 September 2006
> >*
> > 'reinit'
> >*
> >  'set gxout fwrite'
> >  'set fwrite c:\onset\data\o_pentad.dat'
> >*
> >*
> >    'sdfopen g:\cdc\uvw\uwnd.1986.nc'
> >    'sdfopen g:\cdc\uvw\vwnd.1986.nc'
> >*
> >* Note: Initialization can only be done after
> opening files
> >*
> >   i=1
> >   while (i <= 73)
> >     'up'i'=0'
> >     'vp'i'=0'
> >     i=i+1
> >   endwhile
> >*
> >   ny=1986
> >   m=1
> >*
> >   while (m <= 40)
> >*
> >    'set lev 850'
> >*
> >    i=1
> >    ti=1
> >    tf=17
> >*
> >* The extra day in leap year is not taken into
> account
> >*
> >    while (i <= 73)
> >*
> >      'up'i'=up'i'+ave(uwnd.'m',t='ti',t='tf',4)'
> >      'vp'i'=vp'i'+ave(vwnd.'m+1',t='ti',t='tf',4)'
> >      i=i+1
> >      ti=ti+20
> >      tf=tf+20
> >    endwhile
> >*
> >*
> >    ny=ny+1
> >    m=m+2
> >*
> >    if (m <= 40)
> >     'sdfopen g:\cdc\uvw\uwnd.'ny'.nc'
> >     'sdfopen g:\cdc\uvw\vwnd.'ny'.nc'
> >     'set dfile 'm
> >    endif
> >*
> >   endwhile
> >*
> >   i=1
> >   while (i <= 73)
> >     'set t 'i
> >     'upm'i'=up'i'/'m-2
> >     'vpm'i'=vp'i'/'m-2
> >     'd ave(upm'i',lon=97,lon=108)'
> >     'd ave(vpm'i',lon=97,lon=108)'
> >     i=i+1
> >   endwhile
> >*
> >  'disable fwrite'
> >*
> >*
> >
> >
>


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