Q: R ggplot2 - Different precision on seperate tick marks
<p>I have been working on creating a histogram of some data I that I have recent generated and in a effort to make the data more readable would like to include the confidence intervals, including having the intervals numerically marked on the tick line. </p>

<p>This has created a small problem with the readability. Using the code below you can see that having mean as a float value will cause all of the tick marks to have the same precision as the mean value leading to a large number of trailing 0's, in this case there are 7 but if you manully set the mean value to something like 3.5 all will have 1 trailing 0.</p>

<p>I was wondering if anyone knows how to set the percision of each mark manually. Ideally I would like to have the marks at 0,1,2,..,10 to be integer while the mean value would have 2 digits of precision shown since I will have a more accurate number listed. </p>

<pre><code>require(ggplot2)
set.seed(1235)

df &lt;- data.frame(x=rexp(1000))

mean = mean(df$x)

ggplot(df, aes(x=x)) + 
  geom_histogram(binwidth = .05, position="dodge", color="black", fill="transparent") + 
  geom_vline(data=df, aes(xintercept=mean), linetype="dashed", color="red") +
  theme_bw() +
  scale_x_continuous(name="Values", expand = c(0, 0), breaks = sort(c(seq(0,10,1), mean)))
</code></pre>

<p><img src="https://i.stack.imgur.com/1wvfz.png" alt="Image of the resultant graph from the code above."> </p>