How to remove space between axis & area-plot in ggplot2?

Question

I have the following dataframe:

uniq <- structure(list(year = c(1986L, 1987L, 1991L, 1992L, 1993L, 1994L, 1995L, 1996L, 1997L, 1998L, 1999L, 2000L, 2001L,         


        

Answer 1

As of ggplot2 version 3, there is an expand_scale() function that you can pass to the expand= argument that lets you specify different expand values for each side of the scale.

As of ggplot2 version 3.3.0, expand_scale() has been deprecated in favor of expansion which otherwise functions identically.

It also lets you choose whether you want to the expansion to be an absolute size (use the add= parameter) or a percentage of the size of the plot (use the mult= parameter):

ggplot(data = uniq) + 
  geom_area(aes(x = year, y = uniq.p, fill = uniq.loc), stat = "identity", position = "stack") +
  scale_x_continuous(limits = c(1986,2014), expand = c(0, 0)) +
  scale_y_continuous(limits = c(0,101), expand = expansion(mult = c(0, .1))) +
  theme_bw()

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Since this is my top-voted answer, I thought I'd expand this to better illustrate the difference between add= and mult=. Both options expand the plot area a specific amount outside the data. Using add, expands the area by a absolute amount (in the units used for that axis) while mult expands the area by a specified proportion of the total size of that axis.

In the below example, I expand the bottom using add=10, which extends the plot area by 10 units down to -10. I exapand the top using mult=.15 which extends to top of the plot area by 15% of the total size of the data on the y-axis. Since the data goes from 0-100, that is 0.15 * 100 = 15 units – so it extends up to 115.

ggplot(data = uniq) + 
    geom_area(aes(x = year, y = uniq.p, fill = uniq.loc),
              stat = "identity", position = "stack") +
    scale_x_continuous(limits = c(1986,2014), expand = c(0, 0)) +
    scale_y_continuous(limits = c(0,101),
                       breaks = seq(-10, 115, by=15),
                       expand = expansion(mult = c(0, .15),
                                          add = c(10, 0))) +
    theme_bw()