Thank you very much Alex.

I want to do simple calculations.

Best,

Manuel


2014-03-20 10:35 GMT-06:00 Alex Mandel <tech_dev@wildintellect.com>:

> All such tools are algorithms applied in some way via a raster
> calculator. So the question is what formula or model of Risk Assessment
> do you want to use. It can be a simple calculation based on your layers
> and your knowledge of how important they are.
>
> Or you can use many statistical formulas if you wanted. Marxan is just
> one particular method of doing such calculations. There is no 1 way to
> calculate risk. See
> http://cran.r-project.org/web/views/Environmetrics.html
>
> Once you have the statistical model you want to apply, you can use
> predict to generate values over your area based on your other layers.
>
> The question is not if R can do it, but what do you want R to do.
>
> Thanks,
> Alex
>
>
> On 03/20/2014 09:00 AM, Manuel Spínola wrote:
> > Thank you very much Mike.
> >
> > I have the rasters made with the package ratser, using the function
> > rasterize, distance and distance from points.  I know how to model when
> you
> > have presence or presence/absence data, but in this situation I don´t
> have
> > those type of data and I am looking for a way to do a risk assessment in
> R.
> >  I was reading, an apparently Environmental Risk Surface is something
> that
> > could be done with that type of information.  A software like Marxan
> seems
> > to do that type of analysis, but I don´t know the capabilities of R to do
> > such type of analysis.
> >
> > Best,
> >
> > Manuel
> >
> >
> > 2014-03-20 9:07 GMT-06:00 Michael Treglia <mtreglia@gmail.com>:
> >
> >> Manuel,
> >>
> >> Please correct me if I misunderstand, but you've got vector layers of
> >> Roads, Wetlands, and specific locations, and are need to make Raster
> layers
> >> of how far each pixel would be from these types features, and then
> combine
> >> these distance rasters through some sort of computation to map risk.
> Right?
> >>
> >> I don't think there is package that would do this all for you
> >> automatically (and there are a lot of decisions you'll probably have to
> >> make), but I think the Raster package should have all of the necessary
> >> tools - in particular the functions rasterize(), distance() , and the
> >> raster algebra functions [though to initially import shapefiles you'll
> have
> >> to use another package, maybe rGDAL]. The documentation for the Raster
> >> package is here:
> http://cran.r-project.org/web/packages/raster/index.html
> >>
> >> Post-back as you have specific questions on how to execute specific
> steps,
> >> (and look at examples for specific steps in the documentation - the
> raster
> >> package is very well documented).
> >>
> >> Cheers,
> >> Mike
> >>
> >>
> >> On Wed, Mar 19, 2014 at 9:05 PM, Manuel Spínola <mspinola10@gmail.com
> >wrote:
> >>
> >>> Thank you Mike,
> >>>
> >>> I am thinking in overlay several raster layers, mainly distance raster
> >>> (distance to roads, to specific locations, to wetlands, etc) to assess
> the
> >>> risk of a disease spread that is not yet in the country but could enter
> >>> through migratory birds.
> >>>
> >>> Best,
> >>>
> >>> Manuel
> >>>
> >>>
> >>> 2014-03-19 19:08 GMT-06:00 Michael Treglia <mtreglia@gmail.com>:
> >>>
> >>> Hi Manuel,
> >>>>
> >>>> There may be multiple types of environmental risk surfaces, based on
> >>>> different variables, and using different methods to effectively create
> >>>> indices of risk. Can you provide some more detail about what you are
> trying
> >>>> to do? If there is a paper that explains the general methodology, that
> >>>> would be helpful? If not, perhaps an explanation of the general
> workflow
> >>>> you are thinking, with the data types (raster/vector) would be
> helpful.
> >>>> Also, are there specific steps for which you need help? (e.g.,
> >>>> data-processing, multi-layer raster calculations, etc?)
> >>>>
> >>>> Cheers,
> >>>> Mike
> >>>>
> >>>>
> >>>>
> >>>> 2014-03-19 17:37 GMT-05:00 Manuel Spínola <mspinola10@gmail.com>:
> >>>>
> >>>>> Dear list members,
> >>>>>
> >>>>> Is there any way to do an Environmental Risk Surface in R?
> >>>>>
> >>>>> Best,
> >>>>>
> >>>>> Manuel
> >>>>>
> >>>>>
> >>>>> --
> >>>>> *Manuel Spínola, Ph.D.*
> >>>>>
> >>>>> Instituto Internacional en Conservación y Manejo de Vida Silvestre
> >>>>> Universidad Nacional
> >>>>> Apartado 1350-3000
> >>>>> Heredia
> >>>>> COSTA RICA
> >>>>> mspinola@una.ac.cr
> >>>>> mspinola10@gmail.com
> >>>>> Teléfono: (506) 2277-3598
> >>>>> Fax: (506) 2237-7036
> >>>>> Personal website: Lobito de río <
> >>>>> https://sites.google.com/site/lobitoderio/>
> >>>>> Institutional website: ICOMVIS <http://www.icomvis.una.ac.cr/>
> >>>>>
> >>>>>         [[alternative HTML version deleted]]
> >>>>>
> >>>>>
> >>>>> _______________________________________________
> >>>>> R-sig-Geo mailing list
> >>>>> R-sig-Geo@r-project.org
> >>>>> https://stat.ethz.ch/mailman/listinfo/r-sig-geo
>
>
>


-- 
*Manuel Spínola, Ph.D.*
Instituto Internacional en Conservación y Manejo de Vida Silvestre
Universidad Nacional
Apartado 1350-3000
Heredia
COSTA RICA
mspinola@una.ac.cr
mspinola10@gmail.com
Teléfono: (506) 2277-3598
Fax: (506) 2237-7036
Personal website: Lobito de río <https://sites.google.com/site/lobitoderio/>
Institutional website: ICOMVIS <http://www.icomvis.una.ac.cr/>

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