NetCDF 4.9.3
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simple_xy_nc4_wr.c
Go to the documentation of this file.
1/* Copyright 2019 University Corporation for Atmospheric
2 Research/Unidata. See COPYRIGHT file for conditions of use. */
21#include <stdlib.h>
22#include <stdio.h>
23#include <netcdf.h>
24
25/* This is the name of the data file we will create. */
26#define FILE_NAME "simple_xy_nc4.nc"
27
28/* We are writing 2D data, a 6 x 12 grid. */
29#define NDIMS 2
30#define NX 6
31#define NY 12
32
33/* Handle errors by printing an error message and exiting with a
34 * non-zero status. */
35#define ERRCODE 2
36#define ERR(e) {printf("Error: %s\n", nc_strerror(e)); exit(ERRCODE);}
37
38int
39main()
40{
41 int ncid, x_dimid, y_dimid, varid;
42 int dimids[NDIMS];
43 size_t chunks[NDIMS];
44 int shuffle, deflate, deflate_level;
45 int data_out[NX][NY];
46 int x, y, retval;
47
48 /* Set chunking, shuffle, and deflate. */
49 shuffle = NC_SHUFFLE;
50 deflate = 1;
51 deflate_level = 1;
52
53 /* Create some pretend data. If this wasn't an example program, we
54 * would have some real data to write, for example, model output. */
55 for (x = 0; x < NX; x++)
56 for (y = 0; y < NY; y++)
57 data_out[x][y] = x * NY + y;
58
59 /* Create the file. The NC_NETCDF4 parameter tells netCDF to create
60 * a file in netCDF-4/HDF5 standard. */
61 if ((retval = nc_create(FILE_NAME, NC_NETCDF4, &ncid)))
62 ERR(retval);
63
64 /* Define the dimensions. */
65 if ((retval = nc_def_dim(ncid, "x", NX, &x_dimid)))
66 ERR(retval);
67 if ((retval = nc_def_dim(ncid, "y", NY, &y_dimid)))
68 ERR(retval);
69
70 /* Set up variable data. */
71 dimids[0] = x_dimid;
72 dimids[1] = y_dimid;
73 chunks[0] = NX/4;
74 chunks[1] = NY/4;
75
76 /* Define the variable. */
77 if ((retval = nc_def_var(ncid, "data", NC_INT, NDIMS,
78 dimids, &varid)))
79 ERR(retval);
80 if ((retval = nc_def_var_chunking(ncid, varid, 0, &chunks[0])))
81 ERR(retval);
82 if ((retval = nc_def_var_deflate(ncid, varid, shuffle, deflate,
83 deflate_level)))
84 ERR(retval);
85
86 /* No need to explicitly end define mode for netCDF-4 files. Write
87 * the pretend data to the file. */
88 if ((retval = nc_put_var_int(ncid, varid, &data_out[0][0])))
89 ERR(retval);
90
91 /* Close the file. */
92 if ((retval = nc_close(ncid)))
93 ERR(retval);
94
95 printf("*** SUCCESS writing example file simple_xy_nc4.nc!\n");
96 return 0;
97}
EXTERNL int nc_close(int ncid)
Close an open netCDF dataset.
Definition dfile.c:1300
EXTERNL int nc_create(const char *path, int cmode, int *ncidp)
Create a new netCDF file.
Definition dfile.c:398
EXTERNL int nc_def_dim(int ncid, const char *name, size_t len, int *idp)
Define a new dimension.
Definition ddim.c:121
EXTERNL int nc_def_var_deflate(int ncid, int varid, int shuffle, int deflate, int deflate_level)
Set the zlib compression and shuffle settings for a variable in an netCDF/HDF5 file.
Definition dvar.c:461
EXTERNL int nc_def_var(int ncid, const char *name, nc_type xtype, int ndims, const int *dimidsp, int *varidp)
Define a new variable.
Definition dvar.c:214
EXTERNL int nc_def_var_chunking(int ncid, int varid, int storage, const size_t *chunksizesp)
Define storage and, if chunked storage is used, chunking parameters for a variable.
Definition dvar.c:729
Main header file for the C API.
#define NC_NETCDF4
Use netCDF-4/HDF5 format.
Definition netcdf.h:162
#define NC_INT
signed 4 byte integer
Definition netcdf.h:38
#define NC_SHUFFLE
Control the HDF5 shuffle filter.
Definition netcdf.h:336