title: How to lower main title in gridExtra's grid.arrange?
body: <p>I created a diagram using gridExtra's grid.arrange and tried to add a Main title for the entire plot before saving it to a .png file.</p>
  
  <p>Using the <code>main="TITLE"</code> argument works but it is flushed with the top border, regardless of the height I set the diagram.</p>
  
  <p><strong>My question: how do I set it such that the main title is not flushed with the top border?</strong> One way would be to add an overall margin to the entire diagram, but again, I could not figure out how.</p>
  
  <p>As an example, I modified SandyMuspratt and Baptiste's code from <a href="https://stackoverflow.com/questions/10708315/grid-arrange-to-place-table-and-graph-on-one-image">grid arrange to place table and graph on one image</a>:</p>
  
  <pre><code>library(ggplot2)
  library(gridExtra)
  
  x = read.table(text = "
                 1/1/2010 10
                 1/2/2010 20
                 1/3/2010 15
                 1/4/2010 56
                 1/5/2010 46
                 1/6/2010 15
                 1/8/2010 15
                 1/9/2010 15
                 1/10/2010 20
                 1/11/2010 15
                 1/12/2010 15
                 1/13/2010 40
                 1/14/2010 15
                 1/15/2010 15
                 1/16/2010 70", sep = "", header = FALSE)
  
  p1&lt;-ggplot(x, aes(V2, V1)) + geom_point()
  p2&lt;-tableGrob(x)
  
  png( filename = "TEST.png", width = 1700, height = 900, units = "px")
  grid.arrange(p2, p1, main=textGrob("Total Data and Image", gp=gpar(cex=3)), 
               ncol = 2,widths=unit.c(grobWidth(p2), unit(1,"npc") - grobWidth(p2)))
  dev.off()
  </code></pre>
  
  <p>The PNG output to show title flushed with border:
  <img src="https://i.stack.imgur.com/lunhW.png" alt="PNG Output"></p>
  
  <p>I suspect the solution could be rather simple but I can't seem to find a solution online. I have read ?grid.arrange, <a href="https://stackoverflow.com/questions/11774703/adding-text-to-a-grid-table-plot">Adding text to a grid.table plot</a> and other posts, but none mentioned this.</p>
  
  <p>Any help would be appreciated and thanks in advance!</p>