How do I add a custom `labels` for just one tick?

Question

I'm making a chart where the X axis will have '%'.

ggplot(
  data = cars,
  aes(
    x = speed,
    y = dist
  )
) + 
  geom_point() +
  scale_x_continuous(
    labels = function(x) paste0(x,'%'),
  )

This produces a chart.

I only want either the first tick or last tick on the X axis to have the '%'. How do I do this?

If you make this a [reproducible question](https://stackoverflow.com/questions/5963269/how-to-make-a-great-r-reproducible-example), including a representative sample of the data, someone can most likely help out — camille, Sep 17 '18 at 15:26

score 3 · Accepted Answer · answered Sep 17 '18 at 15:49

3

Just change your function to

labels = function(x) c(paste0(x[1] * 100, '%'), x[-1])

(note you may have to adjust your breaks and/or limits because in the updated example you posted, the first element of x is not plotted, so in that case you would need to do c(paste0(x[1:2] * 100, '%'), x[-(1:2)]))

answered Sep 17 '18 at 15:49

konvas

14,126
2
40
46

Thanks. This changes only the first tick. That's great. How would I write this code so that only the final tick label is formatted? `function(x) c( x[1], paste0(x[-1]*100, '%') )` removes the '%' from the first tick, but none of the others. – Username Sep 17 '18 at 16:22
For an answer to my question, see Sri Lakshimi's answer. – Username Sep 17 '18 at 19:27

score 1 · Answer 2 · answered Sep 17 '18 at 17:51

1

Format the function in labels to get '%' for the first tick label only

labels = function(x) c(paste0(x[1],'%'),x[-(1)]

To get '%' for last tick label only

labels = function(x) c(x[1:length(x)-1] , paste0(rev(x)[1],'%'))

answered Sep 17 '18 at 17:51

Sri Lakshmi

11
1

How do I add a custom `labels` for just one tick?

2 Answers2