Erase points

Removes points intersecting a polygon feature class

erase.point(y, x, inside = TRUE)

Arguments

y	A SpatialPoints or SpatialPointsDataFrame
x	A SpatialPolygons or SpatialPolygonsDataFrame
inside	(TRUE/FALSE) Remove points inside polygon, else outside polygon

Value

A SpatialPoints or SpatialPointsDataFrame

Note

Used to erase points that intersect polygon(s). If inside=FALSE then the function results in an intersection operation where points that intersect the polygon are retained. This function effectively duplicates the ESRI ArcGIS Erase Point tool.

Author

Jeffrey S. Evans <jeffrey_evans<at>tnc.org>

Examples

library(sp)
library(raster)
library(rgeos)
  data(meuse)
  coordinates(meuse) = ~x+y

# Create systematic sample and polygons
s <- spsample(x=as(extent(meuse), "SpatialPolygons"), n=1000,
              type="regular")
b <- rgeos::gBuffer(s[sample(1:length(s),5),],
                    byid = FALSE, width = 300)

# Erase points based on polygons
s.erase <- erase.point(s, b)
 
 opar <- par(no.readonly=TRUE)
 par(mfrow=c(2,2))
   plot(s, pch=20, main="original data")
   plot(b, main="erased data")
     points(s.erase, pch=20)
   plot(b, main="erased data using inside=FALSE")
     points(erase.point(s, b, inside=FALSE), pch=20)
 par(opar)