title: How to rotate the axis labels in ggplot2?
body: <p>I have the following graph that I generated using ggplot2 <img src="https://i.stack.imgur.com/Wcu61.jpg" alt="enter image description here"></p>
  
  <p>I had <code>finalPlot</code> as the ggplot object. To add labels I used </p>
  
  <pre><code>finalPlot + stat_bin() + scale_x_continuous('Solution Cost') + scale_y_continuous('Number of Solutions')`
  </code></pre>
  
  <p>How can I change the orientation of the y axis label to make it appear horizontal and if possible span it across two lines like</p>
  
  <pre><code>Number of
  Solutions
  </code></pre>