title: Process multiple polygons d3
body: <p>The answer below on drawing a polygon works well for a single polygon. However, what if there are more than one polygon? Simply adding an additional polygon with points seems not to work even though using "select all" would seem to indicate that it would be OK to add a couple more polygons without much problem.. </p>
  
  <p>We have an array of polygons, each of which has an attribute Points which is an array of points.</p>
  
  <p>The first array with polygon should obviously be mapped and the point arrays of each member processed as described. But how to spedify this two-level structure with d3?</p>
  
  <p><a href="https://stackoverflow.com/questions/13204562/proper-format-for-drawing-polygon-data-in-d3">Proper format for drawing polygon data in D3</a></p>