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

Re: NetCDF 4.0 alpha

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 Note that the archive is no longer being updated. We provide the archive for reference; many of the answers presented here remain technically correct, even if somewhat outdated.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: Re: NetCDF 4.0 alpha
  • Date: Fri, 05 Nov 2004 10:22:00 -0700
Hi Dave,

I'm not sure whether Ed answered your question yet, so here's my
answers ...

> I was looking for the alpha version of NetCDF 4.0 that you described
> in your talk at the HDF conference, but the only thing I found in
> the download section has a December 2003 date. I assume there is (or
> will be soon) something newer.  Is it available yet, and if so where
> can I find it?

An alpha release dated November 3, 2004 is now available from the
downloads link:

  http://gforge.unidata.ucar.edu/project/showfiles.php?group_id=7

> Also I have a question (apologies if I just wasn't paying attention)
> that I didn't hear answered in your talk. It seems as if in HDF
> terms NetCDF 4.0 is a specification particular layout of an HDF
> file, rather like HDF-EOS. My question is what happens if you use
> the NetCDF 4.0 interface to read a generic HDF 5.0 file or an
> HDF-EOS 5.0 file. Would it make sense of these files? Does it only
> understand Vgroups and SDS's? Or would it recognize image data and
> Vdata as well?  (Sorry if this is incorrect terminology for HDF 5.0
> -- I'm really only familiar with HDF 4.0 as of now).

You can't read a generic HDF 5.0 file or an HDF-EOS 5.0 file through
the netCDF-4 interface.  It's been designed from the beginning to only
read datasets that were written through the netCDF-4, netCDF-3, or
netCDF-2 interfaces.  HDF5 is used as a storage layer to provide
enhancements to netCDF, such as large files, parallel I/O,
structures, and additional data types, but netCDF-4 is designed to
remain a relatively simple interface, which it would never remain if
it had to deal with the full generality and complexity of HDF5 files.

--Russ