Re: 20000712: a question

Hi Don,

Don Murray writes:
 > >From: Bill Hibbard <hibbard@xxxxxxxxxxxxxxxxx>
 > >Organization: SSEC
 > >Keywords: 200007121209.e6CC9eT00155
 > Mike/Bill -
 > >> Does anyone know if someone is working on providing DODS data
 > >> reading capability for VisAD?
 > >>
 > >
 > >We discussed this among the folks at SSEC and Unidata.  It
 > >is a question of how similar the Java APIs for DODS and netCDF
 > >are.  I think someone said the C APIs are identical, but that
 > >this is not true for their Java APIs.  At any rate, the trick
 > >would be to exploit the existing netCDF adapter for VisAD to
 > >access DODS servers.
 > >
 > >Perhaps one of the experts from Unidata can comment.
 > At first glance, one would think they could just use the DODS
 > HTTP request using netCDF format and it should seamlessly go into
 > VisAD.  However, that is not the case because the Java netCDF API
 > does not support access to a remote file using the NetcdfFile class
 > which is what the VisAD netCDF adapter (Plain) uses.

Another reason this wouldn't work on a DODS URL is because the data
returned is not in netCDF format.  (Don: what you and I looked at was
removing the DODS part of the URL and just trying to access a web
accessible netCDF file via HTTP.)  For a DODS access in VisAD to work,
there would have to be some DODS client software on the VisAD end.
Either, as I described in my earlier note, a DODS version of the Java
netCDF library or, now that I think of it, the more direct route of
making a VisAD DODS adaptor that calls the DODS Java API.

We've thought more about the first option than the second because:
option one would also be valuable outside the VisAD community; and
with option two, the use of attribute conventions would have to be
added instead of taking advantage of the netCDF conventions already
in the VisAD netCDF adaptor.

Ethan R. Davis                       Telephone: (303) 497-8155
Software Engineer                    Fax:       (303) 497-8690
UCAR Unidata Program Center          E-mail:    edavis@xxxxxxxx
P.O. Box 3000
Boulder, CO  80307-3000    

  • 2000 messages navigation, sorted by:
    1. Thread
    2. Subject
    3. Author
    4. Date
    5. ↑ Table Of Contents
  • Search the visad archives: