/* This is part of the netCDF package.
   Copyright 2006 University Corporation for Atmospheric Research/Unidata.
   See COPYRIGHT file for conditions of use.

   This example writes some surface pressure and temperatures. It is
   intended to illustrate the use of the netCDF Java API. The companion
   program sfc_pres_temp_rd.java shows how to read the netCDF data file
   created by this program.

   This example demonstrates the netCDF Java API.

   Full documentation of the netCDF Java API can be found at:
   http://www.unidata.ucar.edu/software/netcdf-java/
*/

import ucar.nc2.NetcdfFileWriteable;
import ucar.nc2.Dimension;
import ucar.ma2.DataType;
import ucar.ma2.ArrayFloat;
import ucar.ma2.InvalidRangeException;

import java.util.ArrayList;
import java.io.IOException;

public class Sfc_pres_temp_wr {


    public static void main(String args[]) throws Exception
    {
        final int NLAT = 6;
        final int NLON = 12;
        final float SAMPLE_PRESSURE = 900.0f;
        final float SAMPLE_TEMP = 9.0f;
        final float START_LAT = 25.0f;
        final float START_LON = -125.0f;


        // Create the file.
        String filename = "sfc_pres_temp.nc";
        NetcdfFileWriteable dataFile = null;

        try {
            //Create new netcdf-3 file with the given filename
            dataFile = NetcdfFileWriteable.createNew(filename, false);

            // In addition to the latitude and longitude dimensions, we will
            // also create latitude and longitude netCDF variables which will
            // hold the actual latitudes and longitudes. Since they hold data
            // about the coordinate system, the netCDF term for these is:
            // "coordinate variables."
            Dimension latDim = dataFile.addDimension("latitude", NLAT );
            Dimension lonDim = dataFile.addDimension("longitude", NLON );
            ArrayList dims =  null;


            dataFile.addVariable("latitude", DataType.FLOAT, new Dimension[] {latDim});
            dataFile.addVariable("longitude", DataType.FLOAT, new Dimension[] {lonDim});

            // Define units attributes for coordinate vars. This attaches a
            // text attribute to each of the coordinate variables, containing
            // the units.

            dataFile.addVariableAttribute("longitude", "units", "degrees_east");
            dataFile.addVariableAttribute("latitude", "units", "degrees_north");

            // Define the netCDF data variables.
            dims =  new ArrayList();
            dims.add(latDim);
            dims.add(lonDim);
            dataFile.addVariable("pressure", DataType.FLOAT, dims);
            dataFile.addVariable("temperature", DataType.FLOAT, dims);

            // Define units attributes for variables.
            dataFile.addVariableAttribute("pressure", "units", "hPa");
            dataFile.addVariableAttribute("temperature", "units", "celsius");

            // Write the coordinate variable data. This will put the latitudes
            // and longitudes of our data grid into the netCDF file.
            dataFile.create();


            ArrayFloat.D1 dataLat = new ArrayFloat.D1(latDim.getLength());
            ArrayFloat.D1 dataLon = new ArrayFloat.D1(lonDim.getLength());

            // Create some pretend data. If this wasn't an example program, we
            // would have some real data to write, for example, model
            // output.
            int i,j;


            for (i=0; i<latDim.getLength(); i++) {
                dataLat.set(i,  START_LAT + 5.f * i );
            }

            for (j=0; j<lonDim.getLength(); j++) {
               dataLon.set(j,  START_LON + 5.f * j );
            }


            dataFile.write("latitude", dataLat);
            dataFile.write("longitude", dataLon);

            // Create the pretend data. This will write our surface pressure and
            // surface temperature data.

            ArrayFloat.D2 dataTemp = new ArrayFloat.D2(latDim.getLength(), lonDim.getLength());
            ArrayFloat.D2 dataPres = new ArrayFloat.D2(latDim.getLength(), lonDim.getLength());

            for (i=0; i<latDim.getLength(); i++) {
                for (j=0; j<lonDim.getLength(); j++) {
                   dataTemp.set(i,j,  SAMPLE_TEMP + .25f * (j * NLAT + i));
                   dataPres.set(i,j,  SAMPLE_PRESSURE + (j * NLAT + i));
                }
            }

            int[] origin = new int[2];

            dataFile.write("pressure", origin, dataPres);
            dataFile.write("temperature", origin, dataTemp);


        } catch (IOException e) {
              e.printStackTrace();
        } catch (InvalidRangeException e) {
              e.printStackTrace();
        } finally {
            if (null != dataFile)
            try {
                dataFile.close();
            } catch (IOException ioe) {
                ioe.printStackTrace();
            }
       }
       System.out.println( "*** SUCCESS writing example file sfc_pres_temp.nc!" );
    }
}