Am 13.04.2014 um 20:57 schrieb Roger Bivand <Roger.Bivand at nhh.no>:
On Sun, 13 Apr 2014, Stefan Jelkovich wrote:
Hi all,
I?m struggling with the creation of a SpatialPoints/SpatialPointsDataFrame object containing MultiPoints. Is this possible at all?
Why would it be possible, as each geomtry feature (point) is associated with unique observed data values? A multipoint object is of little use in point pattern analysis or geostatistics (or other areas of spatial statistics) as its support is hard to use - the single unique observed data value for each geometry would be associated with multiple points, and a set of such objects might well overlap mutually, meaning that it would be very hard to retrieve observations.
If you feel that multipoint objects have a future in spatial statistics, please contribute a suitable class container and methods for handling it.
Hope this clarifies,
Roger
# SinglePoints are that easy:
library(sp)
data(meuse)
coordinates(meuse) <- ~x+y
# MultiPolygons are that easy:
p1 <- Polygon(cbind(x=c(0, 0, 10, 10, 0), y=c(0, 10, 10, 0, 0)))
p2 <- Polygon(cbind(x=c(13, 13, 17, 17, 13), y=c(13, 17, 17, 13, 13)))
lp <- list(p1, p2)
pls <- Polygons(lp, ID="1")
mp <- SpatialPolygons(list(pls))
How can I put all the meuse data points in one MultiPoint object?
Stefan