[R-sig-Geo] grf and RasterLayer

[Robert J. Hijmans]

Alaios,

> Do you know how I can have not fixed resolution in a RasterLayer?

That is not directly possible. Perhaps you can have a set of
RasterLayers at different resolutions; and then for a given area (grid
cell at the lowest resolution) use the values of the RasterLayer that
has non-NA values; or devise some other scheme like that. Can't help
you with the geoR question.

Robert



On Mon, Aug 2, 2010 at 3:25 AM, Alaios <alaios at yahoo.com> wrote:
>  Hello.
> I am pretty new to R and to geoR as well.
>
>
>   A) I would like to implement an area of X*X  km that would be used to
> "Simulate" an
>
> area map (eg. city's area, suburban area).
>
> -X would be a parameter so I do not want it to be fixed
> -In this map I would like to place users (people), thus I do not know in advance
>
> if in one place there would be one,two, or more users..
> -I would also like to not have fixed resolution in my map and specify it as a
> parameter during run-time. In my X*X area I would like sometimes to have
> resolution of 1Km and others resolution of 10 meters. As resolution increases (1
>
> km->100m->10m) less users would be found in the same "place".
>
> Do you know how I can have not fixed resolution in a RasterLayer?
>
>
>
>   B)I also need some help regarding grf()
>
> According to the geoR short manual grf() takes the following arguments
>
>
>
>    * n number of points (spatial locations) in each simulations.
>    * grid optional. An n в 2 matrix with coordinates of the simulated data.
>    * nx optional. Number of points in the X direction.
>    * ny optional. Number of points in the Y direction.
>
> What I want to create is a matrix (at least this is a matlab in matrix) that
> contains values created from grf(). The array is of dimensions x*y so the grf()
> needs to create a x*y map.
>
> If you see the parameters again you will notice that there is a n (n number of
> points) and nx and ny also.
>
> If I put nx=400 and ny=200 (this is just an example) the grf() will return
> values for 400 cells (for some reason picks the highest values of nx and ny). If
> I try something like n=x*y I get the message that the RandomField package must
> be used. Really do you what the parameter n is about (number of points))?
>
> I would like to thank you in advance for your help
>
> Best Regards
> Alex.
>
>
>
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