[R] diffusing GIS data in maps

[Felix Andrews]

Package akima allows simple 2D interpolation from points to a grid.


On 8/14/07, Lawrence D. Brenninkmeyer <ldb at outsourcethinking.com> wrote:
> Hi-
>
> I am trying to find a way to diffuse GIS data on a European map. I have a
> dataset consisting of particular locations scattered across Europe,
> along with magnitude and value information. I can plot these as discrete
> points with something like the following:
>
> "geocode" is a dataframe with four columns: LAT; LONG; MAGNITUDE;VALUE.
>
> library(maps)
> library(mapdata)
> map("worldHires", regions=c("Germany", "Belgium", "Netherlands"))
> points(geocode$LONG, geocode$LAT, cex=geocode$MAGNITUDE / 2500,
> col=rainbow(length(geocode$VALUE), start=0, end=.4)[rank(geocode$VALUE)])
>
> This gives me a map of Europe with my datapoints highlighted in two ways:
> magnitude is represented by the size of the point, and value is
> represented by the color.
>
> However, what I would really like is for there to be some sort of
> diffusion, such that instead of discrete points, the European map is
> covered in color so I can see more clearly whether there are regional
> patterns (something that will presumably look like this contour chart:
> <http://addictedtor.free.fr/graphiques/RGraphGallery.php?graph=20>  only
> on the European map).
>
> I have absolutely no idea where to start because I can't find a function
> that will allow me to diffuse the datapoints on a map.
>
> thank you for any help
> ldb
>
> ______________________________________________
> R-help at stat.math.ethz.ch 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.
>


-- 
Felix Andrews / 安福立
PhD candidate
Integrated Catchment Assessment and Management Centre
The Fenner School of Environment and Society
The Australian National University (Building 48A), ACT 0200
Beijing Bag, Locked Bag 40, Kingston ACT 2604
http://www.neurofractal.org/felix/
voice:+86_1051404394 (in China)
mobile:+86_13522529265 (in China)
mobile:+61_410400963 (in Australia)
xmpp:foolish.android at gmail.com
3358 543D AAC6 22C2 D336  80D9 360B 72DD 3E4C F5D8