big difference between ncdf and RNetCDF ?

[jannis-2]

Dear package authors, dear r-help list,


are there any big differences between the ncdf and the RNetCDF package,
especially with regards to the support of different netcdf versions,
future maintenacne or speed? I have looked at both packages and their
capabilities seem to be quiet identical (with regards to their
functions). I ask because I will give some advice on ncdf and R to a
group of people highlighting some of the (possible) differences.


Thanks a lot
Jannis

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[David W. Pierce]

As far as I know, RNetCDF does not support version 4 format netcdf files,
while ncdf4 (which is the current version and should be used in preference
to ncdf) does.

They also differ philosophically. RNetCDF is closer to being a
straightforward implementation of the C language interface to the netcdf
library in R. Ncdf4 is closer to being an interface that maps a netcdf file
conveniently into an R style of programming. Which one is preferable
depends on your programming background and what you are more familiar and
comfortable with.

I have not timed RNetCDF. The newest versions of ncdf4 are pretty close to
straight C speed (although the older versions are slower -- I've been
working on improving the efficiency recently).

I use ncdf4 pretty much every day, which means that I keep it up to date
with regards to new versions of the netcdf library. However, it is worth
pointing out that either RNetCDF or ncdf4 depends on having the underlying
netcdf library available on the platform you are using. On some platforms
-- notably windows 64 -- that can be problematic.

Regards,

--Dave



On Tue, Sep 17, 2013 at 9:09 AM, Jannis <[hidden email]> wrote:

> Dear package authors, dear r-help list,
>
>
> are there any big differences between the ncdf and the RNetCDF package,
> especially with regards to the support of different netcdf versions, future
> maintenacne or speed? I have looked at both packages and their capabilities
> seem to be quiet identical (with regards to their functions). I ask because
> I will give some advice on ncdf and R to a group of people highlighting
> some of the (possible) differences.
>
>
> Thanks a lot
> Jannis
>

--
David W. Pierce
Division of Climate, Atmospheric Science, and Physical Oceanography
Scripps Institution of Oceanography, La Jolla, California, USA
[phone] (voice)  /  [phone] (fax)    [hidden email]

        [[alternative HTML version deleted]]

______________________________________________
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.

[pavel.michna]

Dear Dave

Thanks a lot for your reply and pointing out the important differences between ncdf4 and RNetCDF!

Exactly as you write, RNetCDF is currently limited to the version 3 data model. There are still plans to implement the new data model, however we will need to make some restrictions on data types which cannot be represented directly in R (such as n-bit data types). Any comments and ideas on this topic would be appreciated.

Current plans for RNetCDF will be more background work and debugging of small bugs before we will start with the version 4 data model.

Regards,
Pavel

------------------------------------------------------------
Dr. Pavel Michna
Climatology Research Group
Institute of Geography
University of Bern
Hallerstrasse 12
CH-3012 Bern/Switzerland

E-Mail: [hidden email]<mailto:[hidden email]>
------------------------------------------------------------

Am 17.09.2013 um 18:32 schrieb David W. Pierce <[hidden email]<mailto:[hidden email]>>:

As far as I know, RNetCDF does not support version 4 format netcdf files, while ncdf4 (which is the current version and should be used in preference to ncdf) does.

They also differ philosophically. RNetCDF is closer to being a straightforward implementation of the C language interface to the netcdf library in R. Ncdf4 is closer to being an interface that maps a netcdf file conveniently into an R style of programming. Which one is preferable depends on your programming background and what you are more familiar and comfortable with.

I have not timed RNetCDF. The newest versions of ncdf4 are pretty close to straight C speed (although the older versions are slower -- I've been working on improving the efficiency recently).

I use ncdf4 pretty much every day, which means that I keep it up to date with regards to new versions of the netcdf library. However, it is worth pointing out that either RNetCDF or ncdf4 depends on having the underlying netcdf library available on the platform you are using. On some platforms -- notably windows 64 -- that can be problematic.

Regards,

--Dave



On Tue, Sep 17, 2013 at 9:09 AM, Jannis <[hidden email]<mailto:[hidden email]>> wrote:
Dear package authors, dear r-help list,


are there any big differences between the ncdf and the RNetCDF package, especially with regards to the support of different netcdf versions, future maintenacne or speed? I have looked at both packages and their capabilities seem to be quiet identical (with regards to their functions). I ask because I will give some advice on ncdf and R to a group of people highlighting some of the (possible) differences.


Thanks a lot
Jannis



--
David W. Pierce
Division of Climate, Atmospheric Science, and Physical Oceanography
Scripps Institution of Oceanography, La Jolla, California, USA
[phone] (voice)  /  [phone] (fax)    [hidden email]<mailto:[hidden email]>


        [[alternative HTML version deleted]]

______________________________________________
[hidden email] mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.