title: changing multiple line title in multiplot ggplot2 using grid.arrange
body: <p>I have followed the advice on the discussion </p>
  
  <p><a href="https://stackoverflow.com/questions/14726078/changing-title-in-multiplot-ggplot2-using-grid-arrange">changing title in multiplot ggplot2 using grid.arrange</a></p>
  
  <p>but my 2-line title doesn't change the font size.</p>
  
  <p>1- should I state main in grid.arrange or do I use grid.arrange without main and then, add the following script</p>
  
  <pre><code>main=textGrob(paste("titleLine1", "titleLine2", sep = "\n"),gp=gpar(fontsize=20))
  </code></pre>
  
  <p>Thanks</p>
  
  <p>Carol</p>