NetCDF  4.8.1
simple_xy_rd.c
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1 /* Copyright 2019 University Corporation for Atmospheric
2  Research/Unidata. See COPYRIGHT file for conditions of use. */
16 #include <stdlib.h>
17 #include <stdio.h>
18 #include <netcdf.h>
19 
20 /* This is the name of the data file we will read. */
21 #define FILE_NAME "simple_xy.nc"
22 
23 /* We are reading 2D data, a 6 x 12 grid. */
24 #define NX 6
25 #define NY 12
26 
27 /* Handle errors by printing an error message and exiting with a
28  * non-zero status. */
29 #define ERRCODE 2
30 #define ERR(e) {printf("Error: %s\n", nc_strerror(e)); exit(ERRCODE);}
31 
32 int
33 main()
34 {
35  /* This will be the netCDF ID for the file and data variable. */
36  int ncid, varid;
37 
38  int data_in[NX][NY];
39 
40  /* Loop indexes, and error handling. */
41  int x, y, retval;
42 
43  /* Open the file. NC_NOWRITE tells netCDF we want read-only access
44  * to the file.*/
45  if ((retval = nc_open(FILE_NAME, NC_NOWRITE, &ncid)))
46  ERR(retval);
47 
48  /* Get the varid of the data variable, based on its name. */
49  if ((retval = nc_inq_varid(ncid, "data", &varid)))
50  ERR(retval);
51 
52  /* Read the data. */
53  if ((retval = nc_get_var_int(ncid, varid, &data_in[0][0])))
54  ERR(retval);
55 
56  /* Check the data. */
57  for (x = 0; x < NX; x++)
58  for (y = 0; y < NY; y++)
59  if (data_in[x][y] != x * NY + y)
60  return ERRCODE;
61 
62  /* Close the file, freeing all resources. */
63  if ((retval = nc_close(ncid)))
64  ERR(retval);
65 
66  printf("*** SUCCESS reading example file %s!\n", FILE_NAME);
67  return 0;
68 }
NC_NOWRITE
#define NC_NOWRITE
Set read-only access for nc_open().
Definition: netcdf.h:125
nc_get_var_int
int nc_get_var_int(int ncid, int varid, int *ip)
Definition: dvarget.c:1063
nc_close
EXTERNL int nc_close(int ncid)
Definition: dfile.c:1291
netcdf.h
nc_inq_varid
EXTERNL int nc_inq_varid(int ncid, const char *name, int *varidp)
Definition: dvarinq.c:60
nc_open
EXTERNL int nc_open(const char *path, int mode, int *ncidp)
Open an existing netCDF file.
Definition: dfile.c:655