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/*! \file
An example program demonstrating a simple 2D write.
*/
#include <stdlib.h>
#include <stdio.h>
#include <netcdf.h>
/* This is the name of the data file we will create. */
#define FILE_NAME "simple_xy.nc"
/* We are writing 2D data, a 6 x 12 grid. */
#define NDIMS 2
#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()
{
/* When we create netCDF variables and dimensions, we get back an
* ID for each one. */
int ncid, x_dimid, y_dimid, varid;
int dimids[NDIMS];
/* This is the data array we will write. It will be filled with a
* progression of numbers for this example. */
int data_out[NX][NY];
/* Loop indexes, and error handling. */
int x, y, retval;
/* Create some pretend data. If this wasn't an example program, we
* would have some real data to write, for example, model
* output. */
for (x = 0; x < NX; x++)
for (y = 0; y < NY; y++)
data_out[x][y] = x * NY + y;
/* Always check the return code of every netCDF function call. In
* this example program, any retval which is not equal to NC_NOERR
* (0) will cause the program to print an error message and exit
* with a non-zero return code. */
/* Create the file. The NC_CLOBBER parameter tells netCDF to
* overwrite this file, if it already exists.*/
if ((retval = nc_create(FILE_NAME, NC_CLOBBER, &ncid)))
ERR(retval);
/* Define the dimensions. NetCDF will hand back an ID for each. */
if ((retval = nc_def_dim(ncid, "x", NX, &x_dimid)))
ERR(retval);
if ((retval = nc_def_dim(ncid, "y", NY, &y_dimid)))
ERR(retval);
/* The dimids array is used to pass the IDs of the dimensions of
* the variable. */
dimids[0] = x_dimid;
dimids[1] = y_dimid;
/* Define the variable. The type of the variable in this case is
* NC_INT (4-byte integer). */
if ((retval = nc_def_var(ncid, "data", NC_INT, NDIMS,
dimids, &varid)))
ERR(retval);
/* End define mode. This tells netCDF we are done defining
* metadata. */
if ((retval = nc_enddef(ncid)))
ERR(retval);
/* Write the pretend data to the file. Although netCDF supports
* reading and writing subsets of data, in this case we write all
* the data in one operation. */
if ((retval = nc_put_var_int(ncid, varid, &data_out[0][0])))
ERR(retval);
/* Close the file. This frees up any internal netCDF resources
* associated with the file, and flushes any buffers. */
if ((retval = nc_close(ncid)))
ERR(retval);
printf("*** SUCCESS writing example file simple_xy.nc!\n");
return 0;
}
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