title: Adjust margins of grob object in r
body: <p>I made a grob object using the <code>cowplot</code> package. I'm adding <code>grid.lines()</code> and <code>grid.text()</code> objects to finished grob but as it comes out of cowplot it fills the whole page. How can I adjust the margins of the grob object to add some white space around the edges? Example code below. </p>
  
  <pre><code>library(ggplot2)
  library(cowplot)
  
  p1 &lt;- ggplot(mtcars, aes(disp, mpg)) + 
    geom_point()
  p2 &lt;- ggplot(mtcars, aes(qsec, mpg)) +
    geom_point()
  p3 &lt;- ggplot(mtcars, aes(disp, mpg)) + 
    geom_point()
  p4 &lt;- ggplot(mtcars, aes(qsec, mpg)) +
    geom_point()
  plot_grid(p1, p2, p3, p4, ncol = 2 ,nrow = 2,align="hv")
  </code></pre>