Hi Meg, > I've installed netcdf-4.1.1 on an older virtual machine and have tested it > against various netcdf4 files. In my testing, it does not give an explicit > error, but it does not generate any useful NcML. In later versions, the > explicit error message was added. It seems to me that you will not be able > to generate NcML with the C libraries/executable. Ward is right that "ncdump -x" from version 4.1.1 doesn't work for any netCDF-4 files that use features of the enhanced data model, such as unsigned types, groups, strings, or user-defined types. However, it does provide what looks like useful NcML output for netCDF-4 classic model files, which use the netCDF-4/HDF5 format but only features from the classic netCDF-3 data model. The netCDF-4.3.2 version of ncdump likewise works to provide NcML output for netCDF-4 classic model files when the "-x" option is used. You can check whether a file is netCDF-4 format or netCDF-4 classic model format using "ncdump -k" on the file. Ward is also right that netCDF-Java provides a Java ncdump that works to provide NcML output even for netCDF-4 files that use the netCDF-4 enhanced data model, which the C version of the utility can't yet handle. --Russ > I've done a bit of digging, and it appears that you might be able to use the > netcdf-java library to generate NcML for netcdf4 files, however. Most of the > netcdf-java developers are out of the office for the upcoming Christmas > holiday, but I've done some testing by hand and it appears to work on my test > files. > > After downloading the 'netcdfAll-4.5.jar' file from > http://www.unidata.ucar.edu/downloads/netcdf/index.jsp, I followed the > instructions found at > http://www.unidata.ucar.edu/software/thredds/current/netcdf-java/reference/manPages.html#ncdump, > e.g. > > $ java -Xmx1g -classpath netcdfAll-4.5.jar ucar.nc2.NCdump > $HOME/Desktop/ncfiles/netcdf4_test.nc -ncml > > Perhaps this solution would work for you? I wish I could say with more > confidence that netcdf4 support was implemented completely, but it should be > fairly easy to test. > > I hope this helps, > > -Ward > > > > Hello, > > > > We've encountered a strange situation where someone with ncdump version > > 4.1.1 is able to run ncdump with the -x flag on netCDF4s, whereas those of > > us with later versions (4.3.2) cannot. My understanding was the NCML > > extraction feature had never been implemented for netCDF4, but apparently > > this is incorrect. Can you let me know what the status is? If possible, > > we'd like to run ncdump -x on netCDF4s. > > > > Thanks, > > > > Meg Tilton > > > > -- > > Margaret Tilton > > Cooperative Institute for Research in Environmental Sciences (CIRES) at > > University of Colorado at Boulder and > > NOAA National Geophysical Data Center, Solar and Terrestrial Physics > > Division > > 325 Broadway, E/GC2 > > Boulder, Colorado 80305 > > 303-497-6223 > > > > Russ Rew UCAR Unidata Program address@hidden http://www.unidata.ucar.edu Ticket Details =================== Ticket ID: NRE-269426 Department: Support netCDF Priority: Normal Status: Closed
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