Re: CDL limit ?

> Organization: NCAR/CGD
> Keywords: 199411232108.AA04548 ncgen
> From: address@hidden (Charlie Zender)

Hi Charlie,

> i'm using a perl script to generate CDL files out of some pretty big ascii
> model (CCM2) output files. i then use ncgen to create a binary netcdf
> file. the ncgen command is working on "small" CDL files--- 8
> one-dimensional floats with a dimension length of under a thousand.  but
> i'm encountering mysterious syntax errors when i ncgen some larger CDL
> files.  it could be a problem with perl, but i also want to know if
> there's any default internal limit to the number of elements a field can
> have in a CDL file?

No, the limit to the number of values in a variable on a machine where
longs are at least 32 bits is 2**31-1, which is 2147483647.

There are limits on the number of dimensions, variables, and attributes that
can be defined in a netCDF file.  From netcdf.h, these are:

/*
 * These maximums are enforced by the interface, to facilitate writing
 * applications and utilities.  However, nothing is statically allocated to
 * these sizes internally.
 */
#define MAX_NC_DIMS 32           /* max dimensions per file */
#define MAX_NC_ATTRS 512         /* max global or per variable attributes */
#define MAX_NC_VARS 512          /* max variables per file */
#define MAX_NC_NAME 128          /* max length of a name */
#define MAX_VAR_DIMS MAX_NC_DIMS /* max per variable dimensions */

--
Russ Rew                                                UCAR Unidata Program
address@hidden                                          P.O. Box 3000
http://www.unidata.ucar.edu/                          Boulder, CO 80307-3000