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#include <stdio.h>
#include "cdi.h"
#define nlon 12 // Number of longitudes
#define nlat 6 // Number of latitudes
#define nlev 5 // Number of levels
#define nts 3 // Number of time steps
int
main(void)
{
int gridID, zaxisID1, zaxisID2, taxisID;
int vlistID, varID1, varID2, streamID;
SizeType numMissVals = 0;
double lons[nlon] = { 0, 30, 60, 90, 120, 150, 180, 210, 240, 270, 300, 330 };
double lats[nlat] = { -75, -45, -15, 15, 45, 75 };
double levs[nlev] = { 101300, 92500, 85000, 50000, 20000 };
double var1[nlon * nlat];
double var2[nlon * nlat * nlev];
// Create a regular lon/lat grid
gridID = gridCreate(GRID_LONLAT, nlon * nlat);
gridDefXsize(gridID, nlon);
gridDefYsize(gridID, nlat);
gridDefXvals(gridID, lons);
gridDefYvals(gridID, lats);
// Create a surface level Z-axis
zaxisID1 = zaxisCreate(ZAXIS_SURFACE, 1);
// Create a pressure level Z-axis
zaxisID2 = zaxisCreate(ZAXIS_PRESSURE, nlev);
zaxisDefLevels(zaxisID2, levs);
// Create a variable list
vlistID = vlistCreate();
// Define the variables
varID1 = vlistDefVar(vlistID, gridID, zaxisID1, TIME_VARYING);
varID2 = vlistDefVar(vlistID, gridID, zaxisID2, TIME_VARYING);
// Define the variable names
vlistDefVarName(vlistID, varID1, "T");
vlistDefVarName(vlistID, varID2, "P");
cdiDefKeyInt(vlistID, CDI_GLOBAL, CDI_KEY_CENTRE, 252);
cdiDefKeyInt(vlistID, CDI_GLOBAL, CDI_KEY_SUBCENTRE, 0);
cdiDefKeyInt(vlistID, CDI_GLOBAL, CDI_KEY_MPIMTYPE, 1);
cdiDefKeyInt(vlistID, CDI_GLOBAL, CDI_KEY_MPIMCLASS, 2);
cdiDefKeyInt(vlistID, CDI_GLOBAL, CDI_KEY_MPIMUSER, 1403);
cdiDefKeyInt(vlistID, CDI_GLOBAL, CDI_KEY_REVSTATUS, 0);
unsigned char revNumber[] = { 187, 128, 50, 251, 161, 44, 146, 63, 154, 149, 83, 90, 81, 103, 109, 138, 157, 216, 208, 64 };
cdiDefKeyBytes(vlistID, CDI_GLOBAL, CDI_KEY_REVNUMBER, revNumber, 20);
// Create a Time axis
taxisID = taxisCreate(TAXIS_ABSOLUTE);
// Assign the Time axis to the variable list
vlistDefTaxis(vlistID, taxisID);
// Create a dataset in netCDF format
streamID = streamOpenWrite("example_loc.grb", CDI_FILETYPE_GRB2);
if (streamID < 0)
{
fprintf(stderr, "%s\n", cdiStringError(streamID));
return (1);
}
// Assign the variable list to the dataset
streamDefVlist(streamID, vlistID);
// Loop over the number of time steps
for (int tsID = 0; tsID < nts; tsID++)
{
// Set the verification date to 1985-01-01 + tsID
taxisDefVdate(taxisID, 19850101 + tsID);
// Set the verification time to 12:00:00
taxisDefVtime(taxisID, 120000);
// Define the time step
streamDefTimestep(streamID, tsID);
// Init var1 and var2
for (size_t i = 0; i < nlon * nlat; i++) var1[i] = 1.1;
for (size_t i = 0; i < nlon * nlat * nlev; i++) var2[i] = 2.2;
// Write var1 and var2
streamWriteVar(streamID, varID1, var1, numMissVals);
streamWriteVar(streamID, varID2, var2, numMissVals);
}
// Close the output stream
streamClose(streamID);
// Destroy the objects
vlistDestroy(vlistID);
taxisDestroy(taxisID);
zaxisDestroy(zaxisID1);
zaxisDestroy(zaxisID2);
gridDestroy(gridID);
return 0;
}
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