Fix position_dodge example. Fixes tidyverse#755

Author: wch

R/position-dodge.r

@@ -11,8 +11,9 @@
 #' # see ?geom_boxplot and ?geom_bar for more examples
 #' 
 #' # Dodging things with different widths is tricky
-#' df <- data.frame(x=c("a","a","b","b"), y=1:4)
-#' (p <- qplot(x, y, data=df, position="dodge", geom="bar", stat="identity"))
+#' df <- data.frame(x=c("a","a","b","b"), y=1:4, g = rep(1:2, 2))
+#' (p <- qplot(x, y, data=df, group=g, position="dodge", geom="bar",
+#'   stat="identity"))
 #' 
 #' p + geom_linerange(aes(ymin = y-1, ymax = y+1), position="dodge")
 #' # You need to explicitly specify the width for dodging

man/position_dodge.Rd

@@ -22,8 +22,9 @@ ggplot(diamonds, aes(x=price, fill=cut)) + geom_bar(position="dodge")
 # see ?geom_boxplot and ?geom_bar for more examples
 
 # Dodging things with different widths is tricky
-df <- data.frame(x=c("a","a","b","b"), y=1:4)
-(p <- qplot(x, y, data=df, position="dodge", geom="bar", stat="identity"))
+df <- data.frame(x=c("a","a","b","b"), y=1:4, g = rep(1:2, 2))
+(p <- qplot(x, y, data=df, group=g, position="dodge", geom="bar",
+  stat="identity"))
 
 p + geom_linerange(aes(ymin = y-1, ymax = y+1), position="dodge")
 # You need to explicitly specify the width for dodging

man/qplot.Rd

@@ -30,7 +30,7 @@
 
   \item{geom}{character vector specifying geom to use.
   Defaults to "point" if x and y are specified, and
-  "histogram" is on x is specified.}
+  "histogram" if only x is specified.}
 
   \item{stat}{character vector specifying statistics to
   use}