netcdf-c/examples/C/simple_xy_rd.c
2010-06-03 13:23:50 +00:00

70 lines
1.9 KiB
C

/* This is part of the netCDF package.
Copyright 2006 University Corporation for Atmospheric Research/Unidata.
See COPYRIGHT file for conditions of use.
This is a simple example which reads a small dummy array, which was
written by simple_xy_wr.c. This is intended to illustrate the use
of the netCDF C API.
This program is part of the netCDF tutorial:
http://www.unidata.ucar.edu/software/netcdf/docs/netcdf-tutorial
Full documentation of the netCDF C API can be found at:
http://www.unidata.ucar.edu/software/netcdf/docs/netcdf-c
$Id: simple_xy_rd.c,v 1.9 2006/08/17 23:00:55 russ Exp $
*/
#include <stdlib.h>
#include <stdio.h>
#include <netcdf.h>
/* This is the name of the data file we will read. */
#define FILE_NAME "simple_xy.nc"
/* We are reading 2D data, a 6 x 12 grid. */
#define NX 6
#define NY 12
/* Handle errors by printing an error message and exiting with a
* non-zero status. */
#define ERRCODE 2
#define ERR(e) {printf("Error: %s\n", nc_strerror(e)); exit(ERRCODE);}
int
main()
{
/* This will be the netCDF ID for the file and data variable. */
int ncid, varid;
int data_in[NX][NY];
/* Loop indexes, and error handling. */
int x, y, retval;
/* Open the file. NC_NOWRITE tells netCDF we want read-only access
* to the file.*/
if ((retval = nc_open(FILE_NAME, NC_NOWRITE, &ncid)))
ERR(retval);
/* Get the varid of the data variable, based on its name. */
if ((retval = nc_inq_varid(ncid, "data", &varid)))
ERR(retval);
/* Read the data. */
if ((retval = nc_get_var_int(ncid, varid, &data_in[0][0])))
ERR(retval);
/* Check the data. */
for (x = 0; x < NX; x++)
for (y = 0; y < NY; y++)
if (data_in[x][y] != x * NY + y)
return ERRCODE;
/* Close the file, freeing all resources. */
if ((retval = nc_close(ncid)))
ERR(retval);
printf("*** SUCCESS reading example file %s!\n", FILE_NAME);
return 0;
}