[netcdf-java] grib2 read error

• To: netcdf-java@xxxxxxxxxxxxxxxx
• Subject: [netcdf-java] grib2 read error
• From: Sachin Kumar Bhate <skbhate@xxxxxxxxxxxxxxx>
• Date: Wed, 21 Jan 2009 23:34:54 -0500

John,

I am trying to read a section of aggregated grib2 data files.
All subsets are read fine except when start index for time range
is '0'.

I have tested this with nj2.22 as well as 4.0 (developmental version).

A sample code is shown below.

>>>> start
String uri = ww3-multi.ncml;
String var='Significant_height_of_combined_wind_waves_and_swell';

            GridDataset gid = GridDataset.open(uri);

            Range yrange = new Range(1,20,1);
            Range xrange = new Range(1,40,2);

             GeoGrid subg = Grid.subset(trange,null,yrange,xrange);

            Array d = ve.read();
            gid.close();

<<<<<< end

I get this error..

java.lang.NullPointerException

   at ucar.grib.grib2.Grib2DataSection.<init>(Grib2DataSection.java:131)
   at ucar.grib.grib2.Grib2Data.getData(Grib2Data.java:129)

   at ucar.nc2.NetcdfFile.readData(NetcdfFile.java:1368)
   at ucar.nc2.Variable._read(Variable.java:926)
   at ucar.nc2.Variable.read(Variable.java:621)
   at ucar.nc2.ncml.Aggregation$Dataset.read(Aggregation.java:1250)
   at ucar.nc2.ncml.Aggregation.read(Aggregation.java:689)
   at ucar.nc2.dataset.VariableDS._read(VariableDS.java:277)
   at ucar.nc2.Variable.read(Variable.java:646)
   at SubsetGrid.main(SubsetGrid.java:55)


For test purposes the NcML and grib files (zipped) can be accessed via

http://www.gri.msstate.edu/rsearch_data/nopp/ww3-multi.zip

thanks,

-Sachin

--
Sachin Kumar Bhate, Research Associate
MSU-High Performance Computing Collaboratory, NGI
John C. Stennis Space Center, MS 39529
http://www.northerngulfinstitute.org/