Re: decoders] First post - GRIB2 decoders

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/
===============================================================================