title: Plot a geographical map with symbols according to frequencies
body: <p>I would like to plot a geographical map with n numbers of squares according to the frequency of a disease within a county. Like this one here:
  <img src="https://i.stack.imgur.com/fcdu5.jpg" alt="enter image description here"></p>
  
  <p>But I couldn't figure out how to do this with R or qGIS.
  Thanks for y'all help.</p>