[R] using grib files in R

[Roger Bivand]

In addition to Paul's advice, you may find it useful to know that *.grb files
may be read by GDAL drivers in the rgdal package, so that for
http://gribs.ocens.net/NorthEurope.wind.grb.bz2, after downloading and
uncompressing, GDALinfo("NorthEurope.wind.grb") shows the 122 bands in the
file, and readGDAL() will read them into an sp object. Other software may be
needed to access metadata. You will probably also need to set the missing
values to NA manually - in this example file it was necessary to say:

grib <- readGDAL("NorthEurope.wind.grb")
is.na(grib$band1) <- grib$band1 > 100
image(grib, attr=1)

Hope this helps,

Roger


Paul Hiemstra wrote:
> 
> Hi Janet,
> 
> This question would probably be more suited for the r-sig-geo mailing 
> list. In my view, the best option is to use a tool like wgrib to dump 
> the layer you want from the grib file to text and then read it into R 
> using e.g. read.table. See also the spatial data classes provided to R 
> through the sp-package. A good book on spatial data in R is the book by 
> Bivand et al [1]. The spatial task view is another good source of 
> information [2].
> 
> regards,
> Paul
> 
> [1] 
> http://www.springer.com/public+health/epidemiology/book/978-0-387-78170-9
> [2] http://cran.r-project.org/web/views/Spatial.html
> 
> On 08/05/2010 06:37 PM, Janet Nye wrote:
>> I am not new to R, but I am new to .grib files.  I am downloading some
>> climate data and I would like to analyze it in R.  R has a nice netcdf
>> package, but I don’t see any package available to deal specifically
>> with grib files.  I see a few posts from other people using grib files
>> in R.  However, I was unclear if they used grib files in a different
>> software program and then imported the data somehow into R.  Is it
>> possible to use read grib files in R and then use the data?  If so,
>> could someone point me to a book/website that might help me learn how
>> to do this?  Any advice would be helpful…I am beginning to think I
>> should use a different software program, but I’d like to use R!
>>
>> Thanks,
>> Janet
>>
>> ______________________________________________
>> R-help at r-project.org 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.
>>    
> 
> 
> -- 
> Drs. Paul Hiemstra
> Department of Physical Geography
> Faculty of Geosciences
> University of Utrecht
> Heidelberglaan 2
> P.O. Box 80.115
> 3508 TC Utrecht
> Phone:  +3130 253 5773
> http://intamap.geo.uu.nl/~paul
> http://nl.linkedin.com/pub/paul-hiemstra/20/30b/770
> 
> ______________________________________________
> R-help at r-project.org 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.
> 
> 


-----
Roger Bivand
Economic Geography Section
Department of Economics
Norwegian School of Economics and Business Administration
Helleveien 30
N-5045 Bergen, Norway

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