Re: Read netcdf

• To: fabrice.ayreault@xxxxxxx
• Subject: Re: Read netcdf
• From: John Caron <caron@xxxxxxxxxxxxxxxx>
• Date: Tue, 27 Sep 2005 10:52:36 -0600

You can look at the user manual at

 ftp://ftp.unidata.ucar.edu/pub/netcdf-java/v2.2/NetcdfJavaUserManual-2.2.doc

it has some examples in the appendices.

good luck!

fabrice.ayreault@xxxxxxx wrote:

Hi John ,

Thanks for your answer but I have some problems again. So if you can show me an
example to read the data I join a netcdf file I want to read. The problem is
that I want to create a plot in 3 Dimensions with these data so I have to put
them into some tabs. I would like to create a program which works for all kind
of netcdf files.


This is the program I wrote .

import java.rmi.RemoteException;
import ucar.netcdf.Attribute;
import ucar.netcdf.Netcdf;
import ucar.netcdf.NetcdfFile;
import ucar.netcdf.Variable;
import visad.VisADException;


public class Read {

    static String fileName = "c:/output.nc";

    public static void main(String[] args) throws RemoteException,
VisADException{

        if (args.length > 0)
            fileName = args[0];

        try {
            Netcdf nc = new NetcdfFile(fileName, true);
            Variable lat = nc.get("NBLATITUDES75_103");
            int nlats = lat.getLengths()[0];
            double [] lats = new double[nlats];
            int[] index = new int[1];
            for (int ilat = 0; ilat < nlats; ilat++) {
                index [0] = ilat;
                lats[ilat] = lat.getDouble(index);
            }
            String latUnits = lat.getAttribute("units").getStringValue();


            Variable lon = nc.get("NBLONGITUDES231_281");
            int nlons = lon.getLengths()[0];
            double [] lons = new double[nlons];
            int[] index1 = new int[1];
            for (int ilon = 0; ilon < nlons; ilon++) {
                index1 [0] = ilon;
                lons[ilon] = lon.getDouble(index1);
            }
            String lonUnits = lon.getAttribute("units").getStringValue();



            Variable rh = nc.get("GRID_0001");
            String rhUnits = rh.getAttribute("units").getStringValue();
            System.out.println("Units rh : " +rhUnits);
            int[] rhShape = rh.getLengths();

            double[][] rhData = new double[rhShape[0]][rhShape[1]];

            int[] ix = new int[2];
            for (int ilat = 0; ilat < rhData.length; ilat++) {
                ix[0] = ilat;
                for (int ilon = 0; ilon < rhData[0].length ; ilon++) {
                    ix[1] = ilon;
                        rhData[ilat][ilon] = rh.getInt(ix);


                }
            }


        } catch (java.io.IOException e) {
            e.printStackTrace();
        }

    }

}

Thanks and Have a nice day

• References:
  • Re: 20050926: Read netcdf files
    • From: John Caron