1DF2SpatialPointsDataFrame <- structure(function#change data.frame to SpatialPointsDataFrame
2### This function modifies an object of class data.frame to one of class SpatialPointsDataFrame
3(  x, ##<< data frame to be converted
4   coords = c("x", "y"),##<< which columns are coordinates
5   crs = sp::CRS("+init=epsg:28992") ##<< projection scheme
6){
7  #require(sp)
8  sp::coordinates(x) <- ~x+y #c("x", "y")
9  sp::proj4string(x) <- crs;
10  return(x)
11###  the new object of class SpatialPointsDataFrame
12} , ex = function(){
13  if (requireNamespace("sp", quietly = TRUE)) {
14    data("meuse", package = "sp", envir = environment())
15    meuseSP = DF2SpatialPointsDataFrame(meuse)
16
17    sp::plot(meuseSP, asp = 1, cex = 4 * meuse$zinc/max(meuse$zinc),
18         pch = 1, col = as.numeric(meuse$ffreq)+1 )
19    data("meuse.riv", package = "sp", envir = environment())
20    lines(meuse.riv)
21  } else {
22    print("package sp must be installed for this example")
23  }
24
25
26})
27