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Ed,Is a zero-length attribute in netCDF the same as a scalar, or is it more like an empty array? I can't imagine a use for the latter, but if it's needed it's needed.
Mike At 12:45 PM 11/10/2003, Ed Hartnett wrote:
Howdy all! The topic of the day is the perhaps mythical zero length attribute. Why would one want a zero length attribute? I will leave that question for the philosophers among us. Does anyone really use zero-length attributes in the netcdf universe? Probably there is someone out there who does, since there are a large number of users out there. Meanwhile, netcdf supports a zero length attribute, but HDF5, apparently, does not. When I try to create one I get:HDF5-DIAG: Error detected in HDF5 library version: 1.6.1 thread 0. Back trace follows. #000: H5S.c line 1708 in H5Screate_simple(): zero sized dimension for non-unlimited dimensionmajor(01): Function arguments minor(05): Bad value Woops! So that doesn't work. My reading of the manual on H5Acreate informs me that: Currently only simple dataspaces are allowed for attribute dataspaces. So I can't use an extensible attribute. What do you think, Quincey, is there a way to have a zero length attribute in HDF5? Thanks! Ed
-- Mike Folk, Scientific Data Tech (HDF) http://hdf.ncsa.uiuc.edu NCSA/U of Illinois at Urbana-Champaign 217-244-0647 voice605 E. Springfield Ave., Champaign IL 61820 217-244-1987 fax