title: Mapping the world on ggplot2
body: <p>I've been trying to plot a map of the world on ggplot2. I followed the threads of emails: <a href="https://stackoverflow.com/questions/9558040/ggplot-map-with-l">ggplot map with l</a> but I do run into the same error message and I don't understand the author comments on how to fix it. </p>
  
  <pre><code>library(rgdal)
  library(ggplot2)
  library(maptools)
  library(sp)
  gpclibPermit()
  
  world.map &lt;- readOGR(dsn="data", layer="TM_WORLD_BORDERS_SIMPL-0.3")
  world.ggmap &lt;- fortify(world.map, region = "NAME")
  
  &gt; world.ggmap &lt;- fortify(world.map, region = "NAME")
  Error in nchar(ID) : invalid multibyte string 1
  </code></pre>