snapshot...

modules/util/util.py

@@ -135,14 +135,14 @@ def add_time_range_to_filename(pathname, tstart, tend=None):
     return path
 
 
-def haversine_np(lon1, lat1, lon2, lat2):
+def haversine_np(lon1, lat1, lon2, lat2, earth_radius=6367.0):
     """
     Calculate the great circle distance between two points
     on the earth (specified in decimal degrees)
 
     (lon1, lat1) must be broadcastable with (lon2, lat2).
-
     """
+
     lon1, lat1, lon2, lat2 = map(np.radians, [lon1, lat1, lon2, lat2])
 
     dlon = lon2 - lon1
@@ -150,8 +150,8 @@ def haversine_np(lon1, lat1, lon2, lat2):
 
     a = np.sin(dlat/2.0)**2 + np.cos(lat1) * np.cos(lat2) * np.sin(dlon/2.0)**2
 
-    c = 2 * np.arcsin(np.sqrt(a))
-    km = 6367 * c
+    c = 2.0 * np.arcsin(np.sqrt(a))
+    km = earth_radius * c
     return km