Question

Using ggplot, is it possible to get “R-style” x/y axes that don’t meet at the origin and that instead consist of two disconnected ranges, as in the following example?

The reason here is mainly to get ggplot plots to look consistent next to pure-R ones.

Answer 1

Try this,

library(ggplot2)

d <- data.frame(x=1:10, y=rnorm(10))

base_breaks_x <- function(x){
  b <- pretty(x)
  d <- data.frame(y=-Inf, yend=-Inf, x=min(b), xend=max(b))
  list(geom_segment(data=d, aes(x=x, y=y, xend=xend, yend=yend), inherit.aes=FALSE),
       scale_x_continuous(breaks=b))
}
base_breaks_y <- function(x){
  b <- pretty(x)
  d <- data.frame(x=-Inf, xend=-Inf, y=min(b), yend=max(b))
  list(geom_segment(data=d, aes(x=x, y=y, xend=xend, yend=yend), inherit.aes=FALSE),
       scale_y_continuous(breaks=b))
}

ggplot(d, aes(x,y)) +
  geom_point() +
  theme_bw() +
  theme(panel.border = element_blank(),
       panel.grid.major = element_blank(),
       panel.grid.minor = element_blank()) +
  base_breaks_x(d$x) +
  base_breaks_y(d$y)

Edit: a related issue has since been discussed in the ggtheme package, and potentially provides a cleaner solution (no need to provide the data explicitly to the breaks function).