Any limit to the number of files opened ?

[Davide Sotil Bertanzetti]

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'
>*
>*
>
>