Re: decoders] Grib File Data Extraction

I'm having problems spotting the necessary information in the indexer  
output.

I ran the indexer and got the output attached at the end.

Presumably this contains the necessary data for input to Grib1GetData,
namely the byte offset,

Grib1GetData [gribFile] [byte offset] [scale] [BMSExists]

But I can't spot the offset for the data section in the output of the  
indexer.
Where is it?


Indexer output:

index_version = 6.0
grid_edition = 1
location = data/seaTemp1
length = 390002
created = 2008-08-04T17:16:15Z
center = 58
sub_center = 0
table_version = 3
tiles = 1
thin = false
ensemble = false
--------------------------------------------------------------------
0 0 -1 80 78 1 0.0 255 0.0 2008-07-30T12:00:00Z 0 24011925 54 390002 2  
false 58 0 3
--------------------------------------------------------------------
GDSkey = 24011925
grid_type = 0
grid_name = Latitude/Longitude Grid
grid_shape_code = 0
grid_shape = spherical
grid_radius_spherical_earth = 6367.47
Nx = 720
Ny = 361
La1 = -90.0
Lo1 = 0.0
ResCompFlag = 128
Winds = Relative
La2 = 90.0
Lo2 = -0.5
Dx = 0.5
Dy = 0.5
ScanningMode = 64


I want to extract data from the data record. Presmumably the  
Grib1GetData
class does this.


On Aug 2, 2008, at 8:57 AM, Robb Kambic wrote:

> On Fri, 1 Aug 2008, Don McGregor wrote:
>
> > I'm looking for some examples of extracting data from grib files  
> > using
> > the Java decoders.
> > The Grib1Dump utility shows the output at the bottom of this message.
> > However, when I
> > load the file using the code below, I get zero records. I'm new to
> > grib files, and my understanding
> > is that there should be a record for each parameter.
>
>
> Hiya,
>
> GribDump is just to dump the headers of the Grib files, most Grib  
> data is large so we use the index approach and a utility GribGetData  
> ie
>
> Grib(1|2)Indexer to index the records in the Grib file
>
>
> # Grib(1|2)GetData to extract the data on a parameter basis.
> # Parameter and level lookup routines. See Parameters
>
> on the page:
>
> http://www.unidata.ucar.edu/software/decoders/
>
> there are Java docs that explain the routines in detail and what  
> parameters to use.
>
> Robb...
>
>
> >              ucar.unidata.io.RandomAccessFile raf = new
> > ucar.unidata.io.RandomAccessFile("data/seaTemp1","r");
> >              Grib1Input gribInput = new Grib1Input(raf);
> >              System.out.println("GRIB version is " +
> > gribInput.getEdition());
> >
> >              List records = gribInput.getRecords();
> >              System.out.println("Number of records is " +
> > records.size());
> >
> > Dump of the GRIB file:
> >
> >                        Header : GRIB1
> >                    Discipline : 0 Meteorological Products
> >                  GRIB Edition : 1
> >                   GRIB length : 390002
> >            Originating Center : 58 U.S. Navy Fleet Numerical
> > Meteorology and Oceanography Center
> >        Originating Sub-Center : 0 WMO Secretariat
> >            Product Definition : 0 Forecast/Uninitialized Analysis/
> > Image Product
> >            Parameter Category : -1 Meteorological Parameters
> >                Parameter Name : 80 var80 temperature of sea  water
> >               Parameter Units : deg_K
> >                Reference Time : 2008-07-30T12:00:00Z
> >                    Time Units : hour
> >          Time Range Indicator : product valid at RT + P1
> >                   Time 1 (P1) : 0
> >                   Time 2 (P2) : 0
> >       Generating Process Type : 78 126 wave triangular, 28 layer
> > Spectral model from Medium Range Forecast run
> >                    Level Type : 1 surface
> >                 Level Value 1 : 0.0
> >                 Level Value 2 : 0.0
> >                    GDS Exists : true
> >                    BMS Exists : false
> >         Number of data points : 259920
> >                     Grid Name : Latitude/Longitude Grid
> >                     Grid Shape: 0 spherical
> >         Spherical earth radius: 6367.47
> >                            Nx : 720
> >                            Ny : 361
> >                           La1 : -90.0
> >                           Lo1 : 0.0
> >  Resolution & Component flags : 128
> >                         Winds : Relative
> >                           La2 : 90.0
> >                           Lo2 : -0.5
> >                            Dx : 0.5
> >                            Dy : 0.5
> >                 Scanning mode : 64
> >
> >
> > _______________________________________________
> > decoders mailing list
> > address@hidden
> > For list information or to unsubscribe,  visit: 
> > http://www.unidata.ucar.edu/mailing_lists/
>
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> ======================================================================
> Robb Kambic                                Unidata Program Center
> Software Engineer III                      Univ. Corp for Atmospheric Research
> address@hidden             WWW: http://www.unidata.ucar.edu/
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> ======================================================================