CKB style with ggplot

+ ckb_style() does three things to a ggplot2 plot:

1. applies a CKB theme (i.e. change the overall appearance)
2. extends the plotting area and manually adds axis lines (so that you can have a custom sized gap between the plotting area and the axes)
3. applies a fixed aspect ratio

Examples with a scatter plot

Make a scatter plot with ggplot.

plot <- ggplot(data = mpg, aes(x = displ, y = hwy)) + geom_point(size = 1)
plot

Use + ckb_style() to apply a CKB theme, add separated axis lines and fix the aspect ratio.

plot + ckb_style()

Or apply just a CKB theme and use axis lines.

plot + theme_ckb() + theme(axis.line = element_line())

Axis limits

Set axis limits.

plot + ckb_style(xlims = c(0, 8), ylims = c(10, 50))

If you do not want a gap between the axes, set gap = c(0, 0).

plot + ckb_style(xlims = c(0, 8), ylims = c(10, 50), gap = c(0, 0))

Aspect ratio and panel sizes

Change the aspect ratio of the plot.

plot + ckb_style(xlims = c(0, 8),
                 ylims = c(10, 50),
                 ratio = 0.3)

Set the width of the plot (width controls the length of the x axis).

plot + ckb_style(xlims = c(0, 8),
                 ylims = c(10, 50),
                 ratio = 1.5,
                 width = unit(4, "cm"))

Modifying the appearance of the plot

The colour arguments of theme_ckb() and ckb_style() can be used to change the colour of the non-data components of the plot.

plot + ckb_style(xlims = c(0, 8),
                 ylims = c(10, 50),
                 colour = "darkred")

The plot.margin arguments of theme_ckb() and ckb_style() can be used to adjust the margin around the plot.

plot + ckb_style(xlims = c(0, 8),
                 ylims = c(10, 50),
                 plot.margin = margin(2, 2, 2, 2, unit = "cm"))

If you wish to override some aspect of the theme applied by ckb_style() or theme_ckb(), then this can be done by adding a theme after + ckb_style(),

plot + ckb_style(xlims = c(0, 8),
                 ylims = c(10, 50)) +
  theme(axis.title = element_text(colour = "red", face = "plain"))

Warning about axis limits

If any data points you are plotting fall outside the axes, then they will still be drawn and may show up in places such as the axes, the legend, the plot title, or the plot margins. There is also no warning if data points fall outside the whole plot area.

So it is best to check that your xlim and ylim values are suitable for your data before using the function.

# The xlim and ylim ranges are too narrow
plot + ckb_style(xlims = c(0, 4), ylims = c(20, 50))

Bar chart example

ggplot(mpg, aes(class)) + 
  geom_bar() +
  ckb_style(xlims = c(0.5, 7.5),
            ylims = c(0, 70),
            gap = c(0.025, 0.005),
            ratio = 0.5) +
  theme(axis.ticks.x = element_blank())