Skip to contents

Make any ggplot like a CKB plot

Source: vignettes/plot_like_ckb.Rmd
plot_like_ckb.Rmd

plot_like_ckb() 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

Simple 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

Apply just a CKB theme and use axis lines.

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

Or apply the plot_like_ckb function to add separated axis lines and fix the aspect ratio.

plot_like_ckb(plot = plot)

Axis limits

Set axis limits.

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

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

plot_like_ckb(plot = plot, 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_like_ckb(plot = plot, 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_like_ckb(plot = plot, 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 plot_like_ckb() can be used to change the colour of the non-data components of the plot.

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

If you wish to override some aspect of the theme applied by plot_like_ckb, then this can be done by adding a theme after the function.

plot_like_ckb(plot = plot, 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_like_ckb(plot = plot, xlims = c(0, 4), ylims = c(20, 50))

Bar chart example 

barplot <- ggplot(mpg, aes(class)) + geom_bar()
plot_like_ckb(barplot, 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())