change default ndiscr; tidy docs & demo

R/gridlines.R

@@ -15,7 +15,7 @@ degreeLabelsEW = function(x) {
 }
 
 gridlines = function(x, easts = pretty(bbox(x)[1,]),
-	norths = pretty(bbox(x)[2,]), ndiscr = 20)
+	norths = pretty(bbox(x)[2,]), ndiscr = 100)
 {
 	if (missing(x)) {
 		easts = seq(-180,180,20)

demo/polar.R

@@ -3,17 +3,16 @@ library(maps)
 m = map(xlim = c(-180,180), ylim = c(-90,-70), plot = FALSE, fill = TRUE)
 IDs <- sapply(strsplit(m$names, ":"), function(x) x[1])
 library(maptools)
-LL = CRS("+init=epsg:4326")
+m <- map2SpatialPolygons(m, IDs=IDs, proj4string = CRS("+init=epsg:4326"))
+gl = gridlines(m, easts = seq(-180,180,20))
 polar = CRS("+init=epsg:3031")
-m <- map2SpatialPolygons(m, IDs=IDs, proj4string = LL)
-gl = gridlines(m, easts = seq(-180,180,20), ndiscr = 100)
 plot(spTransform(gl, polar))
 plot(spTransform(m, polar), add = TRUE, col = grey(0.8, 0.8))
 l = labels(gl, polar, side = 3)
 # pos is too simple here, use adj:
 l$pos = NULL 
 text(l, adj = c(0.5, -0.3), cex = .85)
-l = labels(gl, polar, side = 4)
-l$srt = 0 # otherwise they end up upside-down
+l = labels(gl, polar, side = 2)
+l$srt = 0 # otherwise they are upside-down
 text(l, cex = .85)
 title("grid line labels on polar projection, epsg 3031")

man/gridlines.Rd

@@ -10,7 +10,7 @@
 \description{ Create N-S and E-W grid lines over a geographic region; create and plot corresponding labels }
 \usage{
 gridlines(x, easts = pretty(bbox(x)[1,]), norths = pretty(bbox(x)[2,]),
- ndiscr = 20) 
+ ndiscr = 100) 
 gridat(x, easts = pretty(bbox(x)[1,]), norths = pretty(bbox(x)[2,]),
  offset = 0.5, side = "WS")
 \method{labels}{SpatialLines}(object, newCRS, side = 1:2, ...)