Hi all I have this polygon and these lines:
library(sp); library(rgeos) # polygon coords <- matrix(c(-1.798123, -1.793072, -1.805767, -1.804129, -1.798123, 55.68066, 55.67369, 55.67508, 55.68139, 55.68066), ncol=2) myPolygon <- Polygons(list(Polygon(coords)), "myPolygon") myPolygon <- SpatialPolygons(list(myPolygon)) proj4string(myPolygon) <- CRS("+proj=longlat +datum=WGS84 +ellps=WGS84 +towgs84=0,0,0") plot(myPolygon) # lines line1 <- matrix(c(-1.79880, -1.79517, 55.67737, 55.67920), ncol=2) line2 <- matrix(c(-1.80231, -1.80679, 55.67764, 55.68004), ncol=2) line1L <- Line(line1) line2L <- Line(line2) my.lines <- Lines(list(line1L, line2L), ID="my.lines") myLines <- SpatialLines(list(my.lines)) proj4string(myLines) <- CRS("+proj=longlat +datum=WGS84 +ellps=WGS84 +towgs84=0,0,0") plot(myLines, add=T) I expected that the code below would remove parts of myPolygon that contain myLines: d <- gDifference(myPolygon, myLines) plot(d) However myPolygon seems unaffected. Why are the parts of myPolygon that contain myLines not being removed? Thanks Ross [[alternative HTML version deleted]] _______________________________________________ R-sig-Geo mailing list R-sig-Geo@r-project.org https://stat.ethz.ch/mailman/listinfo/r-sig-geo