title: Are there easy way to set limit of vertical or horizontal line in ggplot?
body: <p>I want to plot part of <code>geom_vline</code> or <code>geom_hline</code>,codes as follows:</p>
  
  <pre><code>df &lt;- data.frame(x=1:10,y=1:10)
  plt &lt;- ggplot(data=df)+
    geom_point(aes(x=x,y=y))+
    geom_vline(aes(xintercept=x[2]))+
    geom_hline(aes(yintercept=y[2]))
  </code></pre>
  
  <p>I expect to display the left and lower part line as the cross point. 
  but there is no argument such as <code>xlim</code> or <code>ylim</code> in  <code>geom_vline</code> </p>
  
  <p><a href="https://i.stack.imgur.com/YhZMK.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/YhZMK.png" alt="enter image description here"></a></p>