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103 lines
3.3 KiB
C
103 lines
3.3 KiB
C
/* This is part of the netCDF package.
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Copyright 2006 University Corporation for Atmospheric Research/Unidata.
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See COPYRIGHT file for conditions of use.
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This is a very simple example which writes a 2D array of
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sample data. To handle this in netCDF we create two shared
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dimensions, "x" and "y", and a netCDF variable, called "data".
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This example demonstrates the netCDF C API. This is part of the
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netCDF tutorial, which can be found at:
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http://www.unidata.ucar.edu/software/netcdf/docs/netcdf-tutorial
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Full documentation of the netCDF C API can be found at:
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http://www.unidata.ucar.edu/software/netcdf/docs/netcdf-c
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$Id: simple_xy_wr.c,v 1.12 2007/02/14 20:59:21 ed Exp $
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*/
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#include <stdlib.h>
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#include <stdio.h>
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#include <netcdf.h>
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/* This is the name of the data file we will create. */
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#define FILE_NAME "simple_xy.nc"
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/* We are writing 2D data, a 6 x 12 grid. */
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#define NDIMS 2
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#define NX 6
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#define NY 12
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/* Handle errors by printing an error message and exiting with a
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* non-zero status. */
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#define ERRCODE 2
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#define ERR(e) {printf("Error: %s\n", nc_strerror(e)); exit(ERRCODE);}
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int
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main()
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{
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/* When we create netCDF variables and dimensions, we get back an
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* ID for each one. */
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int ncid, x_dimid, y_dimid, varid;
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int dimids[NDIMS];
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/* This is the data array we will write. It will be filled with a
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* progression of numbers for this example. */
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int data_out[NX][NY];
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/* Loop indexes, and error handling. */
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int x, y, retval;
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/* Create some pretend data. If this wasn't an example program, we
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* would have some real data to write, for example, model
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* output. */
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for (x = 0; x < NX; x++)
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for (y = 0; y < NY; y++)
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data_out[x][y] = x * NY + y;
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/* Always check the return code of every netCDF function call. In
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* this example program, any retval which is not equal to NC_NOERR
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* (0) will cause the program to print an error message and exit
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* with a non-zero return code. */
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/* Create the file. The NC_CLOBBER parameter tells netCDF to
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* overwrite this file, if it already exists.*/
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if ((retval = nc_create(FILE_NAME, NC_CLOBBER, &ncid)))
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ERR(retval);
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/* Define the dimensions. NetCDF will hand back an ID for each. */
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if ((retval = nc_def_dim(ncid, "x", NX, &x_dimid)))
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ERR(retval);
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if ((retval = nc_def_dim(ncid, "y", NY, &y_dimid)))
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ERR(retval);
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/* The dimids array is used to pass the IDs of the dimensions of
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* the variable. */
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dimids[0] = x_dimid;
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dimids[1] = y_dimid;
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/* Define the variable. The type of the variable in this case is
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* NC_INT (4-byte integer). */
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if ((retval = nc_def_var(ncid, "data", NC_INT, NDIMS,
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dimids, &varid)))
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ERR(retval);
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/* End define mode. This tells netCDF we are done defining
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* metadata. */
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if ((retval = nc_enddef(ncid)))
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ERR(retval);
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/* Write the pretend data to the file. Although netCDF supports
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* reading and writing subsets of data, in this case we write all
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* the data in one operation. */
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if ((retval = nc_put_var_int(ncid, varid, &data_out[0][0])))
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ERR(retval);
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/* Close the file. This frees up any internal netCDF resources
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* associated with the file, and flushes any buffers. */
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if ((retval = nc_close(ncid)))
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ERR(retval);
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printf("*** SUCCESS writing example file simple_xy.nc!\n");
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return 0;
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}
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