title: How to re-project a map such as "wrld_simpl"?
body: <p>To plot the global map, I simply use:</p>
  
  <pre><code>library(maptools)
  data(wrld_simpl)
  plot(wrld_simpl)
  </code></pre>
  
  <p>It seems that the projection of the plotted map is <code>WGS84</code>. How can I change the projection to another projection.</p>
  
  <p>Thanks for any hint</p>