int TestSuite::testVar()
{
try
{
string FILE_NAME = "tst_vars.nc";
int NDIMS = 4;
int NLAT = 6;
int NLON = 12;
// Names of things.
string LAT_NAME = "latitude";
string LON_NAME = "longitude";
int MAX_ATT_LEN = 80;
// These are used to construct some example data.
float START_LAT = 25.0;
float START_LON = -125.0;
string UNITS = "units";
string DEGREES_EAST = "degrees_east";
string DEGREES_NORTH = "degrees_north";
// For the units attributes.
string LAT_UNITS = "degrees_north";
string LON_UNITS = "degrees_east";
// Return this code to the OS in case of failure.
#define NC_ERR 2
// We will write latitude and longitude fields.
float lats[NLAT],lons[NLON];
// create some pretend data. If this wasn't an example program, we
// would have some real data to write for example, model output.
for (int lat = 0; lat < NLAT; lat++)
lats[lat] = START_LAT + 5. * lat;
for (int lon = 0; lon < NLON; lon++)
lons[lon] = START_LON + 5. * lon;
// Create the file.
NcFile test(FILE_NAME, NcFile::Replace);
// Define the dimensions. NetCDF will hand back an ncDim object for
// each.
NcDim* latDim = test.addDim(LAT_NAME, NLAT);
NcDim* lonDim = test.addDim(LON_NAME, NLON);
// Define the coordinate variables.
NcVar* latVar = test.addVar(LAT_NAME, ncFloat, latDim);
NcVar* lonVar = test.addVar(LON_NAME, ncFloat, lonDim);
// Define units attributes for coordinate vars. This attaches a
// text attribute to each of the coordinate variables, containing
// the units.
latVar->addAtt(UNITS,ncString, DEGREES_NORTH);
lonVar->addAtt(UNITS,ncString, DEGREES_EAST);
// Write the coordinate variable data to the file.
latVar->put(lats, NLAT);
lonVar->put(lons, NLON);
NcValues *latVals = latVar->getValues();
cout<<"toString returns lats: "<<latVals->toString()<<endl;
cout<<"toChar returns "<<latVals->toChar(1)<<endl;
cout<<"toShort returns "<<latVals->toShort(1)<<endl;
cout<<"toInt returns "<<latVals->toInt(1)<<endl;
cout<<"toLong returns "<<latVals->toLong(1)<<endl;
latVals->print(cout);
NcValues *lonVals = lonVar->getValues();
cout<<"toString returns lats: "<<lonVals->toString()<<endl;
lonVals->print(cout);
cout<<"no segmentation fault thus far"<<endl;
//test varaibles here
}
catch(NcException e)
{
e.what();
return 1;
}
try
{
cout<<"should test adding a variable with more than 5 dimensions here"<<endl;
// test creating a variable with more than 5 dimensions
}
catch (NcException e)
{
e.what();
return 1;
}
try //write the file with float's b/c that's all NcValues can handle at the moment
{
int NX = 6;
int NY = 12;
float dataOut[NX][NY];
// Create some pretend data. If this wasn't an example program, we
// would have some real data to write, for example, model output.
for(int i = 0; i < NX; i++)
for(int j = 0; j < NY; j++)
dataOut[i][j] = i * NY + j;
// The default behavior of the C++ API is to throw an exception i
// an error occurs. A try catch block in necessary.
// Create the file. The Replace parameter tells netCDF to overwrite
// this file, if it already exists.
string filename ="simples_xy.nc";
NcFile dataFile(filename, NcFile::Replace);
// When we create netCDF dimensions, we get back a pointer to an
// NcDim for each one.
NcDim* xDim = dataFile.addDim("x", NX);
NcDim* yDim = dataFile.addDim("y", NY);
// Define the variable. The type of the variable in this case is
// ncInt (32-bit integer).
NcVar *data = dataFile.addVar("data", ncFloat, xDim, yDim);
// 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.
data->put(&dataOut[0][0], NX, NY,0,0,0);
// The file will be automatically close when the NcFile object goes
// out of scope. This frees up any internal netCDF resources
// associated with the file, and flushes any buffers.
cout << "*** SUCCESS writing example file simples_xy.nc!" << endl;
}
catch(std::exception e)
{e.what();}
try
{
int NX = 6;
int NY = 12;
// Return this in event of a problem.
// int NC_ERR = 2;
// This is the array we will read.
float dataIn[NX][NY];
// Open the file. The ReadOnly parameter tells netCDF we want
// read-only access to the file.
NcFile dataFile("simples_xy.nc", NcFile::ReadOnly);
// Retrieve the variable named "data"
NcVar *data = dataFile.getVar("data");
//call getType on data
// Read all the values from the "data" variable into memory.
data->get(&dataIn[0][0], NX, NY);
// Check the values.
for (int i = 0; i < NX; i++)
for (int j = 0; j < NY; j++)
if (dataIn[i][j] != i * NY + j)
return 1;
NcValues* dataVar= data->getValues();
cout<<dataVar->toString()<<endl;;
dataVar->print(cout);
}
catch(NcException e)
{
e.what();
return 1;
}
cout<<"***************** Testing Variables was successful *****************"<<endl;
return 0;
}
