title: Modifying ggpairs plot to look like plotmatrix in ggplot2
body: <pre><code>require(GGally)
  data(iris)
  
  ggpairs(dd2, columns = 1:4,
          upper = list(continuous = "points"),
          lower = list(continuous = "cor",params = c(corSize = 10)), 
          diag = list(continuous = "bar"),
          axisLabels = 'show')
  </code></pre>
  
  <p><img src="https://i.stack.imgur.com/H3pHJ.png" alt="enter image description here"></p>
  
  <p>Is there a way to (1) make the background of the panels white i.e. similar to theme_bw() in ggplot2 and remove the grid lines ; (2) can I move the labels (i.e. mpg, cyl etc) to the top and right hand side of the figure, similar to how plotmatrix from ggplot2 looks like; (3) can I remove the Corr in the lower panels and only have the number shown. </p>
  
  <p>I have found a few posts on here that do some of these but they all refer to changing the source?</p>