title: Arrange R plots in a custom layout
body: <p>I would like to combine five plots in R as the following structure:</p>
  
  <p><a href="https://i.stack.imgur.com/iFfXz.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/iFfXz.png" alt="enter image description here"></a></p>
  
  <p>I can use par(mfrow=c(2,3)),however, in that case, the bottom 2 plots (in row 2) are left aligned. How to move these in center? Or if I use layout and matrix, what should be the appropriate dimension for that? It is too mention that all the plots have same width. </p>
  
  <p>Any help is much appreciated.    </p>