/** Draw graph of visiting all the zip codes in numerical order. */
g = new graphics
//g.color[0,0,0,.8]
g.stroke[0.007 deg]
p = new polyline
for [line] lines["file:fsp/neighbors/zipnov99.txt"]
   if [zipLine, lat, long] = line =~ %r/^(\d{5})\t([^\t]+)\t([^\t]+)/
   {
      [lat, long] = eval["[$lat degree, ($long) degree]"]
      if isPrime[parseInt[zipLine]]
         p.addPoint[long, -lat]
   }

g.clipRectSides[-125 deg, -50 deg, -67 deg, -24 deg]
g.add[p]
gi = g.invertGrays[]
g.invertGrays[].show[]
g.write["zipcodesInOrder.png",2048,undef]
g.write["zipcodesInOrder.html",2048,undef]   
gi.write["zipcodesInOrderInv.png",3840,2160]
gi.write["zipcodesInOrderInv.html",4096,undef]