Update news and update documentation

Author: jimhester

NEWS

@@ -13,6 +13,11 @@ ggplot2 0.9.3.1.99
 * Add `"none"` to documentation of `theme()` for parameter `legend.position`.
   (@krlmlr, #829)
 
+MINOR FEATURES
+
+* Allow specifying only one of the limits in a scale and use the automatic
+  calculation of the other limit by passing NA to to the limit function (xlim
+  or ylim). (Fixes #557)  Thanks Jim Hester.
 
 ggplot2 0.9.3.1
 ----------------------------------------------------------------

R/limits.r

@@ -1,7 +1,8 @@
 #' Convenience functions to set the limits of the x and y axis.
 #'
 #' Observations not in this range will be dropped completely and
-#' not passed to any other layers.
+#' not passed to any other layers.  If a NA value is substituted for one of the
+#' limits that limit is automatically calculated.
 #'
 #' @param ... if numeric, will create a continuous scale, if factor or
 #'   character, will create a discrete scale.
@@ -16,12 +17,16 @@
 #' xlim(c(10, 20))
 #' xlim("a", "b", "c")
 #' qplot(mpg, wt, data=mtcars) + xlim(15, 20)
+#' # with automatic lower limit
+#' qplot(mpg, wt, data=mtcars) + xlim(NA, 20)
 #'
 #' # ylim
 #' ylim(15, 20)
 #' ylim(c(10, 20))
 #' ylim("a", "b", "c")
 #' qplot(mpg, wt, data=mtcars) + ylim(15, 20)
+#' # with automatic upper limit
+#' qplot(mpg, wt, data=mtcars) + ylim(15, NA)
 xlim <- function(...) {
   limits(c(...), "x")
 }

man/xylim.Rd

@@ -14,7 +14,8 @@ ylim(...)
 }
 \description{
 Observations not in this range will be dropped completely and
-not passed to any other layers.
+not passed to any other layers.  If a NA value is substituted for one of the
+limits that limit is automatically calculated.
 }
 \examples{
 # xlim
@@ -23,12 +24,16 @@ xlim(20, 15)
 xlim(c(10, 20))
 xlim("a", "b", "c")
 qplot(mpg, wt, data=mtcars) + xlim(15, 20)
+# with automatic lower limit
+qplot(mpg, wt, data=mtcars) + xlim(NA, 20)
 
 # ylim
 ylim(15, 20)
 ylim(c(10, 20))
 ylim("a", "b", "c")
 qplot(mpg, wt, data=mtcars) + ylim(15, 20)
+# with automatic upper limit
+qplot(mpg, wt, data=mtcars) + ylim(15, NA)
 }
 \seealso{
 For changing x or y axis limits \strong{without} dropping data