add id code to nested grid.

Example for 200m

R/nest.grid.R

@@ -12,18 +12,17 @@
 #' @export
 #'
 #' @examples See nest.grid.lux.R
-nest.grid<-function(ingrid,res=250){
+nest.grid<-function(ingrid,res=250,idcol=1){
 
   #get the 5 coords pairs for each input grid cell
   dfcoords<-data.frame(sf::st_coordinates(ingrid))
-  #derive base resolution from difference in Y between first and 2nd pair
-  # of first square:
-  input_r<-abs(dfcoords[1,2]-dfcoords[2,2])
+  #derive base resolution from Y difference of first square:
+  input_r<-sf::st_bbox(ingrid[1,])$ymax-sf::st_bbox(ingrid[1,])$ymin
   if ((input_r %% res) >0){stop("Remainder of dividing input resolution by target resolution not null")}
   # split input into list so child output cell will know parent output cell
   splitted<-split(dfcoords,dfcoords$L2) #dfcoords$L2 identifies polygons
   #reuse input cells names with IN first to avoid numbers to start names and indicate it is input name
-  names(splitted)<-paste0("IN",ingrid$CELLCODE)
+  names(splitted)<-paste0("IN",sf::st_drop_geometry(ingrid)[,idcol])
 
   #sq.polyg function gives the 5 coordinates pairs of the new (smaller) square polygons
   #given the requested resolution r and list of base polygons origin x and origin y

lunested200withCODE.R

@@ -0,0 +1,10 @@
+#lunested200withCODE.R
+
+lukm<-readRDS("data/lukm3035.RDS")
+nested200<-nest.grid(lukm,res=200) ###about 20min
+
+nested200coords<-data.frame(sf::st_coordinates(nested200))
+origincoords200<-nested200coords[match(unique(nested200coords[,"L2"]),nested200coords[,"L2"]),c(1,2)]
+nested200$CELLCODE200m<-paste0("200mE",origincoords200[,1]/100,"N",origincoords200[,2]/100)
+
+sf::st_write(nested200,"data/lunested200.gpkg",delete_dsn=TRUE) #export gpkg