Better default values for position nudge.

Fixes #1428

Author: hadley

NEWS.md

@@ -1,5 +1,8 @@
 # ggplot2 2.0.0.9000
 
+* `position = "nudge"` now works (although it doesn't do anything useful)
+  (#1428).
+
 * You can once again set legend key and height width to unit arithmetic
   objects (like `2 * unit(1, "cm")`) (#1437).
 

R/position-nudge.R

@@ -31,8 +31,8 @@ position_nudge <- function(x = 0, y = 0) {
 #' @usage NULL
 #' @export
 PositionNudge <- ggproto("PositionNudge", Position,
-  x = NULL,
-  y = NULL,
+  x = 0,
+  y = 0,
 
   required_aes = c("x", "y"),