[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

opendap indices subscript

This archive contains answers to questions sent to Unidata support through mid-2025. Note that the archive is no longer being updated. We provide the archive for reference; many of the answers presented here remain technically correct, even if somewhat outdated. For the most up-to-date information on the use of NSF Unidata software and data services, please consult the Software Documentation first.

  • Subject: opendap indices subscript
  • Date: Tue, 03 Apr 2007 12:04:31 +0200
Hi all,
I have a problem when I use the java netcdf API (in version 2.2.18 or 2.2.19) for saving OPeNDAP request results as NetCDF files. 

One example of OPeNDAP URL I use is :
http://www.ifremer.fr/thredds3/dodsC/CORIOLIS-GLOBAL-RTOA/sea_water_temperature/aggregated_time_serie?temperature[0:1][1:2][13:23][13:33] 

I first tried  with these lines of code :

    try {
          NetcdfDatasetCache.disable();
ncfile = (NetcdfFile)NetcdfDataset.acquireDataset(filename, null); 
          FileWriter.writeToFile(ncfile,
                  "/tmp/test.nc",
                  false,
                  0);                    } catch (IOException ioe) {
            System.out.println("trying to open " +  ioe.getMessage());
                  }
...
But the API is trying to download the full dataset by sending to the server a request like : http://www.ifremer.fr/thredds3/dodsC/CORIOLIS-GLOBAL-RTOA/sea_water_temperature/aggregated_time_serie?temperature
Of course the server cannot answer such a request because the volume for the dataset is about 20 Gb...
In order to avoid this, I've created an object in order to set to 'false' the 'preload' static attribute of the 'DODSNetcdfFile' object. 

Now the API sends requests like :
http://www.ifremer.fr/thredds3/dodsC/CORIOLIS-GLOBAL-RTOA/sea_water_temperature/aggregated_time_serie?latitude[0:1:10] 
or
http://www.ifremer.fr/thredds3/dodsC/CORIOLIS-GLOBAL-RTOA/sea_water_temperature/aggregated_time_serie?temperature[0:1:1][0:1:1][0:1:10][0:1:20]
...
(as many as required variables)
It is quite right but the offsets of my array subscript disappear and become '0' for every request and every variable.
It seems that the problem happens in the 'readArrays' method of the 'DODSNetcdfFile' object.
Does anyone already face this problem ? Is this a bug or a mis-use of the API ? 

Thanks in advance for any piece of advice you could give me.

Thomas




===============================================================================
To unsubscribe netcdf-java, visit:
http://www.unidata.ucar.edu/mailing-list-delete-form.html
===============================================================================