# NOT RUN {
library(pgirmess)
# raster creation
library(sp)
data(meuse.grid)
coordinates(meuse.grid) = ~x+y
gridded(meuse.grid) = TRUE
# random selection of points within the raster area
mypoints<-spsample(meuse.grid,n=10,type="random") # random points are appx 10, see spsample doc
mypoints<-SpatialPointsDataFrame(coordinates(mypoints),data.frame(id=1:nrow(mypoints@coords)))
image(meuse.grid,att=3) # distance to the river
plot(mypoints,add=TRUE,pch=20,cex=0.1) # points
for (i in 1:nrow(mypoints@coords)){
polygon(polycirc(50, mypoints@coords[i,]),border="blue") # buffer 50 place
}
for (i in 1:nrow(mypoints@coords)) {
polygon(polycirc(100, mypoints@coords[i,]),border="green") # buffer 100 place
}
mybuffers<-rwhatbufNum(meuse.grid,mypoints,c(50,100),att=3) # get the values in each buffer
names(mybuffers) # two list given
mybuffers[[1]] # list of values for each point (buffer 50)
mybuffers[[1]][[1]] # list of values for the first buffer 50 (point #1)
# }
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