Enhancement suggestion: uses of geodesic distance calculation

[guidoeco]

As an enhancement, the following patch uses the geopy library Vincenty (aliased as geopy.distance.distance) to calculate the geodesic distance between two points. The patch does introduce a dependency on the geopy library, but when tested I found it reduced the number files needed for caching and the time to run by 20-30%. (YMMV.)

@@ -28,6 +28,8 @@
import sys
import math
from loadOsm import LoadOsm
+from geopy import Point
+import geopy.distance

class Router(object):
def init(self, data):
@@ -39,10 +41,9 @@ class Router(object):
lat2 = self.data.rnodes[n2][0]
lon2 = self.data.rnodes[n2][1]
# TODO: projection issues

• dlat = lat2 - lat1
• dlon = lon2 - lon1
• dist2 = dlat * dlat + dlon * dlon
• dist = math.sqrt(dist2)
• p1 = Point(lat1, lon1)
• p2 = Point(lat2, lon2)
• dist = geopy.distance.distance(p1,p2).km
  return(dist)

def doRoute(self,start,end):