Incorrect netCDF file growth

• To: netcdfgroup@xxxxxxxxxxxxxxxx
• Subject: Incorrect netCDF file growth
• From: kegp@xxxxxxxxxxxxx (k.prada)
• Date: Thu, 26 Mar 1992 08:36:45 EST

While modifying a file structure and content to add new variables I
noted file growth out of proportion to the variables added.  It
appeared that NC_LONG, NC_SHORT, and NC_BYTE types require the same
storage space. Experiments with test programs and files produced the
results listed below. The work was done on a Sun Sparc 2, OS 4.1.1,
netCDF 2.02. The test program list follows. Variable types are
changed for each run.

Comments or suggestions appreciated. 

variable 1 - NC_DOUBLE : variable 2 - NC_LONG
file size w/ 1 record = 168  - 2 records = 180 - 3 records = 192 (diff = 12)

variable 1 - NC_DOUBLE : variable 2 - NC_SHORT
file size w/ 1 record = 168  - 2 records = 180 - 3 records = 192 (diff = 12)
                                                                should be 10
variable 1 - NC_DOUBLE : variable 2 - NC_BYTE
file size w/ 1 record = 168  - 2 records = 180 - 3 records = 192 (diff = 12)
                                                                should be 9
variable 1 - NC_LONG : variable 2 - NC_LONG
file size w/ 1 record = 164  - 2 records = 172 - 3 records = 180 (diff = 8)

variable 1 - NC_LONG : variable 2 - NC_SHORT
file size w/ 1 record = 164  - 2 records = 172 - 3 records = 180 (diff = 8)
                                                                should be 6
variable 1 - NC_LONG : variable 2 - NC_BYTE
file size w/ 1 record = 164  - 2 records = 172 - 3 records = 180 (diff = 8)
                                                                should be 5

/*----------------------------------------------------------------------*/
#include <stdio.h>
#include "netcdf.h"

int cdfid;
int v1_id, v2_id;
short v1;
byte v2;

main(argc,argv)
int argc;
char **argv;
{
        int n,i,ix[1];
        
        if(argc < 2)
                n = 1;                          /* default to one record */
        else
                n = atoi(argv[1]);      /* or request number of records */

        docdf();                                /* define and create the file */
        v1 = 1;
        v2 = 2;

        for(i = 0; i < n; i++)  /* write the requested records */
        {
                ix[0] = i;

                ncvarput1(cdfid, v1_id, ix, (void *) &v1);
                ncvarput1(cdfid, v2_id, ix, (void *) &v2);
        }
        ncclose(cdfid);
}       
/*----------------------------------------------------------------------*/
docdf()
{
        int dims[3];
        int record_dim;
                
        cdfid = nccreate("test.cdf", NC_CLOBBER);

        record_dim = ncdimdef(cdfid, "record", NC_UNLIMITED);

        dims[0] = record_dim;

        v1_id = ncvardef (cdfid, "var1", NC_DOUBLE, 1, dims);
        v2_id = ncvardef (cdfid, "var2", NC_SHORT,  1, dims);

        ncattput(cdfid,NC_GLOBAL,"title",NC_CHAR,13,(void *)"CDF TEST DATA");

        ncendef (cdfid);
}
___________________________________________________________________________
            Ken Prada                 |
Applied Ocean Physics and Engineering |Organization is critical to success.
Woods Hole Oceanographic Institution  |
       (508) 457-2000 Ext 2711        |Try eating a soup sandwich.
          kegp@xxxxxxxxxxxxx          |