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Re: decoders] First post - GRIB2 decoders

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  • Subject: Re: decoders] First post - GRIB2 decoders
  • Date: Tue, 26 Feb 2008 15:52:31 -0700 (MST)

On Tue, 26 Feb 2008, Jelle Ferwerda wrote:


Dear Rob,
Finally.. I cracked it. I took one of the files in the indexer, and deleted all that was unneeded for my implementation.
Good job, if you want to read the data for that product you could add the code: 

            Grib2Data g2d    = new Grib2Data(raf);
            float     data[] = g2d.getData(GdsOffset, PdsOffset);

            if (data != null) {
                int row = 0;
                for (int j = 0; j < data.length; j++) {
                    //if( j % 800 == 0 ) // used to test quasi data
                    //ps.println( "row ="+ row++ );
                    ps.println("data[ " + j + " ]=" + data[j]);
                }
            }
            raf.close();


This code was extracted from Grib2GetData.java.


robb...
I realize.. It is not the cleanest code in the world, but I managed to get the gdsoffset; I am sure I can get the rest to work too. Also, I found out that IDL can be called through a java interface, so all the data processing I will just handle in a familiar environment. 

Thanks so much for your assistence!

Cheers,

Jelle.
PS: The code I use now for finding the offset (Still need to integrate & type juggle a bit) is: 


String InFile           = "C:\\java\\data\\MPE_20080222_0915_M9_00.grb";
int   ProdInt           = 0;    // Index nr of product we want

// Yes we want output to memory
Boolean ToMem          = true;
      // Create a unidata specified RandomAccesFile for reading
ucar.unidata.io.RandomAccessFile InRA = new ucar.unidata.io.RandomAccessFile(InFile, "r"); try { 
  InRA.seek(0);

  // Create an index of the file
  Grib2Input g2i = new Grib2Input(InRA);
    g2i.scan(true, false);
     ArrayList products = g2i.getProducts();
     for (int i = 0; i < products.size(); i++) {
if(i==ProdInt) // This I could clean up and just all the ProdInt in once go 
      {
      Grib2Product product = (Grib2Product) products.get(i);
      Grib2ProductDefinitionSection pds = product.getPDS();
      Grib2IdentificationSection    id  = product.getID();
           long GDSOFF = product.getGdsOffset();
      long PDSOFF = product.getPdsOffset();
      System.out.println(GDSOFF);
      System.out.println(PDSOFF);
    }
   }
} catch (NotSupportedException noSupport) {
          System.err.println("NotSupportedException : " + noSupport);
}
      System.out.println(
               "-----------------end------------------------");





-----------------------------------------------
Jelle Ferwerda
Postdoctoral Research Fellow

Animal Behavior Research Group
Department of Zoology / University of Oxford
South Parks Road / Oxford / OX13PS
United Kingdom

email:          address@hidden
Office Phone:   +44 18652 71214
WWW:            http://www.bio-vision.nl
                http://www.cookseasonal.com
-----------------------------------------------



===============================================================================
Robb Kambic                                Unidata Program Center
Software Engineer III                      Univ. Corp for Atmospheric Research
address@hidden             WWW: http://www.unidata.ucar.edu/
===============================================================================