+
+ # fuck knows
+ def lon_potlatch(baselong,masterscale)
+ (self.lon-baselong)*masterscale+350
+ end
+
+ def lat_potlatch(basey,masterscale)
+ -(lat2y(self.lat)-basey)*masterscale+250
+ end
+
+ private
+
+ def lat2y(a)
+ 180/Math::PI * Math.log(Math.tan(Math::PI/4+a*(Math::PI/180)/2))
+ end
+