Creation of large netCDF datasets using ncgen and CDL files

• To: netcdfgroup@xxxxxxxxxxxxxxxx
• Subject: Creation of large netCDF datasets using ncgen and CDL files
• From: Frederic J Chagnon <frederic@xxxxxxx>
• Date: Mon, 16 Oct 2000 13:53:56 -0400

Hi-

I am attempting to create a netCDf file to store some model output, and am 
using a method that has worked for the past year. But now, the file I am 
creating is very large (3 Gb), and there seems to be a problem.

Here's my method:
I have a CDL file in which I define the extents of the domain and all the 
variables. I use the ncgen -o command to create a netCDF file based on the CDL 
file. To test the "goodness" of the file created, I use the ncdump -c command.

This method works well for me if I am creating datasets that are smaller than 
1.5 GB. However, I have just added more time step definitions to my CDL file, 
and while it creates the netCDF file seemlessly, the ncdump -c command returns 
an error.

I have even downloaded the latest version of the netCDf libraries 
(netcdf-3.5-beta) in hope that it would solve the problem, but I have had no 
luck.

I am puzzled, because if I modify the CDL file and decrease either the number 
of variables, or the size of the domain, the resulting netCDF file "works".

Below is the error message from the ncdump -c command. If you could enlighten 
me in any way on the matter, I would be most grateful. i would be glad to 
supply my CDL file (but didn't want to bother you with an attachement unless 
needed.) Thanks.

> ncdump -c OSU_YEAR_2D.nc
netcdf OSU_YEAR_2D {
dimensions:
        londot = 75 ;
        latdot = 50 ;
        loncrs = 75 ;
        latcrs = 50 ;
        levela = 23 ;
        levelb = 24 ;
        levelc = 1 ;
        time = 8760 ;
variables:
        float GROUNDT(time, levelc, latcrs, loncrs) ;
                GROUNDT:long_name = "GROUND TEMPERATURE" ;
(...)

        double time(time) ;
                time:time_origin = "01-JAN-1998:00:00:00" ;
                time:units = "seconds" ;
                time:point_spacing = "even" ;

// global attributes:
                :title = "OSU_YEAR SIMULATION OUTPUT" ;
data:

 londot = ncdump: Invalid argument
>


Frederic Chagnon        (617)253-5483
Ralph M. Parsons Laboratory    48-212
Massachusetts Institute of Technology
Cambridge         MA            02139