Dear all, I am trying to project my LongLat-maps to a plane. The ultimate purpose is to do a search of points in vicinity of other points using overlay-commands (sp) with radius in km.
I am applying spTransform (package rgdal) and it gives my some curious results. An example. Let's take a point lying somewhere in Germany, zone=32U x <- 8.968735 y <- 49.454735 After conversion I sould get something like Easting: 426858 (km) Northing: 5427937 (km) sp1 <- SpatialPoints(matrix(c(x,y), ncol=2), proj4string = CRS("+proj=longlat +datum=WGS84")) sp1Transformed <- spTransform(sp1, CRS("+proj=merc +zone=32u +datum=WGS84")) coordinates(sp1Transformed) coords.x1 coords.x2 [1,] 998395.0133 6319888.068 The result is an obvious nonsense. Well, after some deliberation I swapped the original coordinate columns: x <- 49.454735 y <- 8.968735 sp2 <- SpatialPoints(matrix(c(x,y), ncol=2), proj4string = CRS("+proj=longlat +datum=WGS84")) sp2Transformed <- spTransform(sp2, CRS("+proj=merc +zone=32u +datum=WGS84")) coordinates(sp2Transformed) coords.x1 coords.x2 [1,] 5505275.918 995840.692 Now the northing (which comes first after swapping) looks better, at least it falls within Germany, which is however not to say about the easting. Apparently I am missing an important point by the transformation. Any help will be greatly appreciated! Regards Alex ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.