title: How to display the "Inf" label completly using ggplot2？
body: <p>When I plot a line with infinity value using ggplot2 package, the label of it can not be display completely, even though I use a big "nudge_y" argument. A manual text can get the result, but it is not my answer.
  How to display it completely?</p>
  
  <pre><code>x=seq(1,3,1)
  y=c(1/3,Inf,3/3)
  dt=data.frame(x=x,y=y,z=round(y,2))
  ggplot(dt)+geom_line(aes(x=x,y=y))+
       geom_text(aes(x=x,y=y,label=z))
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/kEs3d.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/kEs3d.png" alt="img"></a></p>