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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 = 64I 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 usingthe 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 ieGrib(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/= = = = = = = = = ======================================================================Robb Kambic Unidata Program Center Software Engineer III Univ. Corp for Atmospheric Research address@hidden WWW: http://www.unidata.ucar.edu/= = = = = = = = = ======================================================================