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2.1.4.2 simple_xy_rd.cpp
     /* This is part of the netCDF package.
        Copyright 2006 University Corporation for Atmospheric Research/Unidata.
        See COPYRIGHT file for conditions of use.
     
        This is a very simple example which reads a 2D array of
        sample data produced by simple_xy_wr.cpp.
     
        This example is part of the netCDF tutorial:
        http://www.unidata.ucar.edu/software/netcdf/docs/netcdf-tutorial
     
        Full documentation of the netCDF C++ API can be found at:
        http://www.unidata.ucar.edu/software/netcdf/docs/netcdf-cxx
     
        $Id: simple_xy_rd.cpp,v 1.13 2007/01/19 12:52:13 ed Exp $
     */
     
     #include <iostream>
     #include <netcdfcpp.h>
     
     using namespace std;
     
     // We are reading 2D data, a 6 x 12 grid.
     static const int NX = 6;
     static const int NY = 12;
     
     // Return this in event of a problem.
     static const int NC_ERR = 2;
     
     int main(void)
     {
        // This is the array we will read.
        int dataIn[NX][NY];
     
        // Open the file. The ReadOnly parameter tells netCDF we want
        // read-only access to the file.
        NcFile dataFile("simple_xy.nc", NcFile::ReadOnly);
     
        // You should always check whether a netCDF file open or creation
        // constructor succeeded.
        if (!dataFile.is_valid())
        {
           cout << "Couldn't open file!\n";
           return NC_ERR;
        }
     
        // For other method calls, the default behavior of the C++ API is
        // to exit with a message if there is an error.  If that behavior
        // is OK, there is no need to check return values in simple cases
        // like the following.
     
        // Retrieve the variable named "data"
        NcVar *data = dataFile.get_var("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 NC_ERR;
     
        // The netCDF file is automatically closed by the NcFile destructor
        cout << "*** SUCCESS reading example file simple_xy.nc!" << endl;
     
        return 0;
     }