title: R heatmap with circles
body: <p>I would like to generate, in R, a heatmap visualization of a matrix using circles, in order to have both the color and diameter of the circles be informative. Something looking like this:
  <a href="https://i.stack.imgur.com/z5XoP.png" rel="noreferrer"><img src="https://i.stack.imgur.com/z5XoP.png" alt="example R heatmap with circles" /></a></p>
  <p>This sort of plotting is called &quot;bubblegum plot&quot; in certain computational biology labs, but I could not find an R function/package to do it.</p>
  <p>Any ideas? Thanks!</p>