title: Pacific-centric Robinson projection with ggplot in R
body: <p>I'm trying to create a pacific-centric Robinson projection in R with ggplot... </p>
  
  <p>converting a shapefile to a Robinson CRS using <code>spTransform</code> and setting longitude to 150 degrees doesn't work, and <code>fortify</code> errors out. </p>
  
  <p>like this:</p>
  
  <pre><code>world_robin &lt;- spTransform(world2, CRS("+proj=robin +lon_0=150 +x_0=0 +y_0=0 +ellps=WGS84 +datum=WGS84 +units=m +no_defs"))
  plot(world_robin, col = "khaki", bg = "azure2")
  </code></pre>
  
  <p>And there doesn't appear to be a way to do it later in the process when setting a projection for ggmap: 
  ie, </p>
  
  <pre><code>coord_map("mollweide", orientation=c(90, 0, 150)) 
  </code></pre>
  
  <p>this appears to be the best, but it's not quite there. </p>