title: Pretty Axis with Min and Max labels
body: <p>I want to draw a simple bar plot like so:</p>
  
  <pre><code>test &lt;- data.frame(y=c(1,3,53,10,30,35,50), x=c(1:7))
  barplot(test$y, names.arg=test$x)
  </code></pre>
  
  <p><img src="https://i.stack.imgur.com/xzhOu.png" alt="resulting graph"></p>
  
  <p>My issue is that the y axis does not extend far enough if the maximum value is some "unpretty" number. What would be better is if the axis extended passed the maximum value and finished on some "pretty" value greater than the maximum. </p>
  
  <p>Given a random dataset (i.e. this is going in a function), is there a simple way of doing this?</p>