title: Mapping my data to a Zip Code area map in R
body: <p>My data is like this:</p>
  
  <pre><code>ZIPcode Cases   longi   lati
  43613   1   -83.604452  41.704307
  44140   1   -81.92148   41.48982
  46052   1   -86.470531  40.051603
  48009   22  -83.213883  42.544619
  48017   6   -83.151815  42.535396
  48021   7   -82.946167  42.463894
  48025   19  -83.265758  42.523195
  </code></pre>
  
  <p>I want to get a map similar to this (if you can see it) in R. The outline should be zipcodes and the shading should be according to number of cases, darker as cases increase.</p>
  
  <p>I'm very new to R. Tried a lot of code I found online but can't get what I want. Any help is appreciated. Can this be done in base SAS ?
  Thank you!</p>
  
  <p><a href="https://i.stack.imgur.com/5Kp3v.png" rel="nofollow noreferrer">enter image description here</a></p>