From ripley at stats.ox.ac.uk  Wed Apr 27 08:41:42 2005
From: ripley at stats.ox.ac.uk (Prof Brian Ripley)
Date: Wed Apr 27 08:41:58 2005
Subject: [Rd] ncdf with opendap/dods support
In-Reply-To: <426F011F.9@noaa.gov>
References: <426F011F.9@noaa.gov>
Message-ID: <Pine.LNX.4.61.0504270735560.18495@gannet.stats>

You need to approach the package maintainers directly: they may well not 
read r-devel.  What you seem to be suggesting is an extra feature for the 
ncdf package.

Note from `B Ripley':  you need libraries for a specific compiler on 
Windows.

Professor Ripley.

On Tue, 26 Apr 2005, Russell Moffitt wrote:

> Aloha,
>
> I just made some quick hacks on the configure script with the 'ncdf' package 
> to make it link with the opendap/dods libraries (opendap.org) rather than the 
> netcdf api library.  Basically, this allows a user to interact in R with a 
> remotely served dataset as if it were a netcdf file on the local filesystem 
> (read-only).  Functionality with local files should continue to work as well. 
> This opendap feature should be greatly useful for a number of fields of 
> scientific computing, including oceanography and climate modelling, where a 
> huge number of data sets are already served via opendap around the world.
>
> In order to do this, the user must install the opendap/dods netcdf libraries 
> on the system and then run
> R CMD INSTALL --configure-args="-with-dods=$DODS_INSTALL_DIR" 
> ncdf_1.3-dods.tar.gz
> where $DODS_INSTALL_DIR is wherever the opendap lib and include directories 
> are found.
>
> My modifications are small and unelegant, but it works, providing that the 
> user can successfully install the opendap libraries.  I am neither a compile 
> guru nor do I have very much experience using and developing for R. 
> Therefore, I would like to see if anyone would be willing to help me make 
> this modification into a more official package/patch that can be shared with 
> other R users.  The biggest obstacle for me is making binaries for Windows. 
> Precompiled opendap libraries are available for windows, so this should be 
> possible.  B Ripley has compiled the 'ncdf' package for windows, and this 
> version should be exactly the same except for different external libraries.
>
> This same modification should also be possible for the RNetCDF/nvar packages 
> since they use the same support libraries.  I just happened to try it with 
> ncdf first.  Which package do more people tend to use/like for accessing 
> netcdf files?
>
> Please let me know if you can provide some assistance in making this modified 
> package as easy to install as possible on unix/linux/windows/etc...  I can 
> provide more info about the opendap library and what is required to link to 
> it if you ask.
>
> Mahalo,
> Russell
>
> P.S.  I imagine that this opendap support in R will allow us to list R on 
> opendap.org's list of client applications, giving R some more exposure.
>
> ______________________________________________
> R-devel@stat.math.ethz.ch mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel
>
>

-- 
Brian D. Ripley,                  ripley@stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595


[Rd] ncdf with opendap/dods support
Prof Brian Ripley