Add geofencing to automation

homeassistant/util/location.py

@@ -1,8 +1,8 @@
 """Module with location helpers."""
 import collections
-from math import radians, cos, sin, asin, sqrt
 
 import requests
+from vincenty import vincenty
 
 
 LocationInfo = collections.namedtuple(
@@ -31,18 +31,6 @@ def detect_location_info():
     return LocationInfo(**data)
 
 
-# From: http://stackoverflow.com/a/4913653/646416
 def distance(lon1, lat1, lon2, lat2):
-    """
-    Calculate the great circle distance in meters between two points specified
-    in decimal degrees on the earth using the Haversine algorithm.
-    """
-    # convert decimal degrees to radians
-    lon1, lat1, lon2, lat2 = (radians(val) for val in (lon1, lat1, lon2, lat2))
-
-    dlon = lon2 - lon1
-    dlat = lat2 - lat1
-    angle = sin(dlat/2)**2 + cos(lat1) * cos(lat2) * sin(dlon/2)**2
-    # Radius of earth in meters.
-    radius = 6371000
-    return 2 * radius * asin(sqrt(angle))
+    """ Calculate the distance in meters between two points. """
+    return vincenty((lon1, lat1), (lon2, lat2)) * 1000