Subject: Re: Who uses HDF?

From: [email-masked] ()
Date: 24 Feb 1995 14:06:10 GMT

In article <[email-masked]>, [email-masked] (Chris Dodge) writes:
|> 
|> In the netCDF FAQ there is a list of who uses netCDF, but we havn't
|> been able to find a similar list for HDF. Does one exist?
|> 
|> We are trying to make a decision as to what data format to use for
|> Ocean flow model output; current contenders are netCDF, HDF or
|> GRIB. Anyone working in this line got any thought on what would be
|> best? From our research so far, it looks like netCDF is probably the
|> best supported and most widely used format......

Chris/Arne/Heinz,

I'm sure that NCSA can give you a more current list, but here are some
of the folks who are known to use HDF:

	Spyglass, Intergraph, Research Systems, Inc (IDL), Silicon
	Graphics, Inc (Explorer), PCI.  All of these companies have
	commercial applications that use HDF.

	NASA's Jet Propulsion Laboratory, Phillips Petroleum, Massachusetts
	General Hospital.  Each of these organizations has adopted HDF
	to fulfill some or all of its internal data storage needs.

In addition, over the next several years, the biggest single user of HDF
will be the Earth Observing System.  EOS will be creating and archiving
several petabytes of remote sensing data, which will be made available
to the Earth Science community using HDF as the standard data format.
As part of this effort, NASA will be encouraging more commercial software
vendors to incorporate HDF capabilities into their data analysis and
visualization tools.

|> Also: What about performance of reading/writing speed of netCDF
|> vs. HDF.

Back when netCDF was first being investigated by the HDF team at NCSA
(I was on the team at the time), HDF was found to be significantly faster
than netCDF.  The difference was due in large part to the reliance of the
netCDF software on the XDR library, which was used to provide cross-platform
portability via IEEE standard data representations.  HDF software includes
its own custom data conversion routines, which produce the same IEEE standard
data representations, but are much faster (and are even specially optimized
on certain platforms like Cray).

Of course, this work was done several years ago.  I'm sure that netCDF has
improved in comparison to HDF since then.  I seem to recall that they have
even replaced the XDR library with their own custom code.

Hope this helps you with your decision.

			-Doug Ilg
			 Hughes STX
			 EOS Data and Information System