Re: [ferret_users] Number of files

[Jaison Kurian <jaison@xxxxxxxxxxxxxxxxxx>]

Hi Faisal,
           The given details are not sufficient to suggest a better
solution to your problem. Anyway...making some wild guess gives
the following answers.

  From the error messgae it seems to be NetCDF files. If your individual 
files are for same XYZ region and differs only in "time", then you have 
two options to do calculations involving all 40 files at the same time :

  1. Using a Descriptor file  
  --------------------------
  This file ties all the specified NetCDF files into a single file along 
  time axis. It is pretty easy to create one. Details about descriptor file
  and its bounds are given in the User Manual at

        Ch10 Sec4.  CREATING A MULTI-FILE NETCDF DATA SET
        Ch4  Sec4.  FERRET PROGRAM LIMITS 
  
  This will give basic ideas and an example for the descriptor file. 
  You can also try serching in Mail Archive/FAQ for some usefull 
  informations, especially for tools to make descriptor files. Also 
  note that this is the ideal solution for files with considerable size.

  2. Merging to a single NetCDF file
  ----------------------------------
  You can open the individual datasets in Ferret and can append data to 
  a common output NetCDF file. Then you can use the new file for calcul-
  ations. This process is very easy if you have proper time axis for 
  each of the 40 NetCDF files. If it does not have one, then you have to
  define a destination time axis and you have to assign the time axis 
  to data from individual files before appending to the new file. This
  method is not appreciable if the individual/combined file size is 
  pretty large.

Try searching in the mail archives 
(http://ferret.pmel.noaa.gov/cgi-bin/marc-search.cgi) with key words like
"32 files" or "too many connects" to see previous mails discussing about
similar problem. 

  Which version of Ferret are you using ? According to the documentation
for Ferret version 6.00, the maximum number of  data sets simultaneously 
open (as seen through SHOW DATA) is 100. I haven't checked this yet. So,
you can give try by switching to new versions....

  If this mail/User Manual/Mail Archive/FAQ didn't help you to solve
your problem, write back with "ALL RELEVANT DETAILS".

Regards,

Jaison   

  

On Tue, 28 Nov 2006, S. Faisal Saeed wrote:

> Dear all,
> 
> It seems that ferret does open more than 33 files at a time. It gives 
> an error of too many connects. I want to open 40 files and do some 
> averaging, is there any simple solution ?
> 
> Regards,
> Faisal
>