[Biomod-commits] Environmental and biotic data at different locations

[Wilfried Thuiller]

There are several packages for loading NetCDF data into R and work with them. Have a look at the raster package if it cannot load NetCDF directly. If it does, the extract function would be perfect


Le 8 déc. 2010 à 15:06, Charles Novaes de Santana a écrit :

> Dear Wilfried,
> 
> Thank you very much for your answer.
> 
> Our environmental data is in NCDF format, that we have downloaded
> here: http://www.esrl.noaa.gov/psd/data/gridded/data.UDel_AirT_Precip.html
> 
> Our biotic data is in ASCII format, but we can try to convert them to
> some raster format.
> 
> Thank you again, best regards!
> 
> Charles
> 
> On Wed, Dec 8, 2010 at 7:12 AM, Wilfried Thuiller
> <wilfried.thuiller at ujf-grenoble.fr> wrote:
>> Dear Charles,
>> Do not too much the interpolations techniques. In which format are your
>> data? Are they originally ArcGIS raster or grid data?
>> If yes, better practice to use the raster package with the extract
>> function.
>> Else, I guess your approach is probably the best one.
>> Best
>> Wilfried
>> 
>> Le 7 déc. 2010 à 21:22, Charles Novaes de Santana a écrit :
>> 
>> Dear all,
>> 
>> First of all, I would like to say "Congratulations" to all the
>> developers of BIOMOD. It is a GREAT tool and I can not imagine the
>> hard work you need to mantain it working so nice! Thank your for
>> everything!
>> 
>> I am just starting to use Biomod, and I have a question that maybe is
>> a tipical "newbie" question :)
>> 
>> My biotic data (presence of species) are not at the same grid that my
>> environmental data (temperature and precipitation). And my
>> environmental data are at a regular grid while my biotic data are at
>> points irregularly spaced.
>> 
>> I think the best thing to do in this case is to make an interpolation
>> of my environmental data to find the values of temperature and
>> precipitation at the same grid points of my biotic data. To do it, I
>> am using the function "interp" from the package "akima". Am I correct?
>> Is ther another option?
>> 
>> Here, just an example similar of my case: environmental data at a
>> regular gridpoint. Biotic data at points irregularly spaced.
>> 
>> environmental$lat <- c(2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5,
>> 7.0, 7.5, 8.0)
>> environmental$lon <- c(-38.5, -38.0, -37.5, -37.0, -36.5, -36.0,
>> -35.5, -35.0, -34.5, -34.0,-33.5, -33.0, -32.5, -32.0, -31.5, -31.0)
>> biotic$lat <- c(4.222, 4.250, 4.34, 4.7, 4.71, 4.77, 4.811, 4.99)
>> biotic$lon<- c(-35.1, -34.8, -34.7, -34.4, -34.38, -34.21, -33.23, -32.77)
>> 
>> biotic$temp <- interp (environmental$lon, environmental$lat,
>> environmental$temp, biotic$lon, biotic$lat)
>> 
>> Thank you in advance for any help!
>> 
>> best regards,
>> 
>> Charles
>> 
>> --
>> Um axé! :)
>> 
>> --
>> Charles Novaes de Santana
>> PhD student - Global Change
>> Laboratorio Internacional de Cambio Global
>> Department of Global Change Research
>> Instituto Mediterráneo de Estudios Avanzados(CSIC/UIB)
>> Calle Miquel Marques 21, 07006
>> Esporles - Islas Baleares - España
>> _______________________________________________
>> Biomod-commits mailing list
>> Biomod-commits at lists.r-forge.r-project.org
>> https://lists.r-forge.r-project.org/cgi-bin/mailman/listinfo/biomod-commits
>> 
>> --------------------------
>> Dr. Wilfried Thuiller
>> Laboratoire d'Ecologie Alpine, UMR CNRS 5553
>> Université Joseph Fourier
>> BP53, 38041 Grenoble cedex 9, France
>> tel: +33 (0)4 76 51 44 97
>> fax: +33 (0)4 76 51 42 79
>> Email: wilfried.thuiller at ujf-grenoble.fr
>> Home page: http://www.will.chez-alice.fr
>> Website: http://www-leca.ujf-grenoble.fr/equipes/tde.htm
>> 
>> FP6 European MACIS project: http://www.macis-project.net
>> FP6 European EcoChange project: http://www.ecochange-project.eu
>> 
>> 
>> 
>> 
>> 
> 
> 
> 
> -- 
> Um axé! :)
> 
> --
> Charles Novaes de Santana
> PhD student - Global Change
> Laboratorio Internacional de Cambio Global
> Department of Global Change Research
> Instituto Mediterráneo de Estudios Avanzados(CSIC/UIB)
> Calle Miquel Marques 21, 07006
> Esporles - Islas Baleares - España
> _______________________________________________
> Biomod-commits mailing list
> Biomod-commits at lists.r-forge.r-project.org
> https://lists.r-forge.r-project.org/cgi-bin/mailman/listinfo/biomod-commits

--------------------------
Dr. Wilfried Thuiller
Laboratoire d'Ecologie Alpine, UMR CNRS 5553
Université Joseph Fourier
BP53, 38041 Grenoble cedex 9, France
tel: +33 (0)4 76 51 44 97
fax: +33 (0)4 76 51 42 79

Email: wilfried.thuiller at ujf-grenoble.fr
Home page: http://www.will.chez-alice.fr
Website: http://www-leca.ujf-grenoble.fr/equipes/tde.htm

FP6 European MACIS project: http://www.macis-project.net
FP6 European EcoChange project: http://www.ecochange-project.eu





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