OK so I have a spatial polygons data frame, and I have a point of interest. I want to add a row to the SPDF that contains the distance from the centroid of each polygon to this given point. How do I do this ?
Here is a toy dataset:
library(sp) library(spdep) library(rgeos) # Create toy SPDF fn <- system.file("etc/shapes/eire.shp", package = "spdep") prj <- CRS("+proj=utm +zone=30 +units=km") eire <- readShapeSpatial(fn, ID = "names", proj4string = prj) # Create a point of interest pt.coords <-readWKT("POINT(260 5900)") eire.proj<-CRS(proj4string(eire)) proj4string(pt.coords) <- eire.proj # check point is on the map plot(eire) plot(pt.coords, col="Red", add=TRUE)
Ok so the SPDF data has following columns:
> names(eire)  "A" "towns" "pale" "size" "ROADACC" "OWNCONS" "POPCHG" "RETSALE" "INCOME" "names"
I want to add a extra column showing the distance from each polygon centroid to the point we defined. How do I do this ?