[netcdf-java] problem accessing CMIP3 via opendap

• To: "netcdf-java@xxxxxxxxxxxxxxxx" <netcdf-java@xxxxxxxxxxxxxxxx>
• Subject: [netcdf-java] problem accessing CMIP3 via opendap
• From: David Rayner <david.rayner@xxxxxxxxx>
• Date: Tue, 9 Aug 2011 12:05:10 +0000

Hi Netcdf-Java Folks,

I have a problem accessing the CMIP3 database at 
esg.llnl.gov<http://esg.llnl.gov> with netcdf-java. eg:

(from within matlab)
url = 
'http://esg.llnl.gov/cgi-bin/dap-cgi.py/ipcc4/20c3m/cccma_cgcm3_1/pcmdi.ipcc4.cccma_cgcm3_1.20c3m.run1.atm.da.xml';
obj =  ucar.nc2.dataset.NetcdfDataset.openDataset(url);

??? Java exception occurred:
java.io.IOException: Error on line 1 of document
http://esg.llnl.gov/cgi-bin/dap-cgi.py/ipcc4/20c3m/cccma_cgcm3_1/pcmdi.ipcc4.cccma_cgcm3_1.20c3m.run1.atm.da.xml:
 XML
document structures must start and end within the same entity.
at ucar.nc2.ncml.NcMLReader.readNcML(NcMLReader.java:233)
at ucar.nc2.ncml.NcMLReader.readNcML(NcMLReader.java:202)
at ucar.nc2.dataset.NetcdfDataset.acquireNcml(NetcdfDataset.java:819)
at ucar.nc2.dataset.NetcdfDataset.openOrAcquireFile(NetcdfDataset.java:677)
at ucar.nc2.dataset.NetcdfDataset.openDataset(NetcdfDataset.java:424)
at ucar.nc2.dataset.NetcdfDataset.openDataset(NetcdfDataset.java:407)
at ucar.nc2.dataset.NetcdfDataset.openDataset(NetcdfDataset.java:392)
at ucar.nc2.dataset.NetcdfDataset.openDataset(NetcdfDataset.java:379)

The same error occurs with ToolsUI launched with WebStart, so I think it is a 
problem with netcdf-java, not matlab. I am using netcdf-4.2.26.jar and friends.

I can access the server using python/cdms2:

>> import cdms2 as cdms
>> url = 
>> 'http://esg.llnl.gov/cgi-bin/dap-cgi.py/ipcc4/20c3m/cccma_cgcm3_1/pcmdi.ipcc4.cccma_cgcm3_1.20c3m.run1.atm.da.xml'
>> f = cdms.open(url)
>> v = f.getVariables()
>> v
[<Variable: va, file: pcmdi.ipcc4.cccma_cgcm3_1.20c3m.run1.atm.da, shape: 
(14600, 9, 48, 96)>,
 <Variable: tas, file: pcmdi.ipcc4.cccma_cgcm3_1.20c3m.run1.atm.da, shape: 
(14600, 48, 96)>,
 <Variable: uas, file: pcmdi.ipcc4.cccma_cgcm3_1.20c3m.run1.atm.da, shape: 
(14600, 48, 96)>,
 <Variable: hfss, file: pcmdi.ipcc4.cccma_cgcm3_1.20c3m.run1.atm.da, shape: 
(14600, 48, 96)>,
 <Variable: lon_bnds, file: pcmdi.ipcc4.cccma_cgcm3_1.20c3m.run1.atm.da, shape: 
(96, 2)>,
...

Similarly, I can access other opendap servers (eg. 
http://ensemblesrt3.dmi.dk/cgi-bin/nph-dods/data/) using netcdf-java (via 
matlab or ToolsUI).

So it appears to me to be some problem specific to the combination 
netcdf-java/esg.llnl.gov.

Any suggestions? Any help appreciated.

dave r.

--
 David Rayner
 Department of Earth Sciences
 University of Gothenburg
 Office +46 (0)31 786 4849
 Mobile +46 (0)738 542 404
 david.rayner@xxxxxxxxx<mailto:david.rayner@xxxxxxxxx>

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