return centroid of offset locations where rides _will be_

model.py

@@ -3,6 +3,7 @@ Object-Document Map for bike model
 """
 from mongoengine import Document, DateTimeField, GeoPointField, \
     FloatField, connection
+import bson
 import datetime
 from LatLon23 import LatLon, Latitude, Longitude
 from geopy import distance
@@ -22,21 +23,30 @@ class Flock:
         bearings = list()
         n = 0
         for b in bikes:
+
+            dt = datetime.datetime.now() - b['last_update']
+            progress = (b['speed'] * dt.seconds) / 1000  # in km
+            point = LatLon(b['point'][1], b['point'][0])
+            next_point = point.offset(b['bearing'], progress)
+            
             speeds.append(b['speed'])
             bearings.append(b.get('bearing', 0))
-            lats.append(float(b['point'][1]))
-            lons.append(float(b['point'][0]))
+            lats.append(float(next_point.lat))
+            lons.append(float(next_point.lon))
             n += 1
 
+
+        self.mean_speed = 0
+        self.size = 0
+        self.centroid = None
+            
         if n > 0:
             self.size = n
             self.mean_speed = sum(speeds) / float(len(speeds))
+
+            
             self.centroid = LatLon(Latitude(sum(lats) / len(lats)),
                                    Longitude(sum(lons) / len(lons)))
-        else:
-            self.mean_speed = 0
-            self.size = 0
-            self.centroid = None
 
 
 class Bike(Document):
@@ -54,6 +64,7 @@ class Bike(Document):
         self.point = (lon, lat)
         self.speed = speed
         self.bearing = bearing
+        self.last_update = datetime.datetime.now()
         self.save()
         
     def heading_to(self, target):
@@ -95,11 +106,16 @@ class Bike(Document):
         # these are bikes around me
         local = [bike for bike in
                  self.db.bike.find(
-                     {'point':
-                      {'$near':
-                       {'$geometry': {'type': 'Point',
+                     {'point': {
+                         '$near': {
+                             '$geometry': {
+                                 'type': 'Point',
                                  'coordinates': self.point},
-                        '$maxDistance': local_radius}}})]
+                             '$maxDistance': local_radius}},
+                      'last_update': {
+                          '$gte': datetime.datetime.now() - datetime.timedelta(minutes=15)},
+                      '_id': {'$ne': bson.objectid.ObjectId(self.id)}})]
+
         local_ids = set([bike['_id'] for bike in local])
 
         # these are going near my destination
@@ -122,7 +138,7 @@ class Bike(Document):
         :return: heading from point to flock centroid, in degrees
         """
         flock = Flock(self.find_flock())
-        if flock.size > 1:  # no flocking with self!
+        if flock.size > 0:  
             flock_heading = self.heading_to(flock.centroid)
             flock_distance = distance.geodesic((self.point[1],
                                                 self.point[0]), (self.destination[1],

server.py

@@ -40,8 +40,4 @@ def update(bike_id):
     bike.update(lat, lon, speed, bearing)
 
     return jsonify(
-        dest_heading=bike.heading_to([bike.destination[1],
-                                      bike.destination[0]]),
-        dest_distance=bike.distance_to(bike.destination),
-        speed=bike.speed,
         **bike.flock_data())