use speed of agent to filter age of db records

README.md

@@ -43,4 +43,9 @@ server, using the following commands:
 	* Running on http://127.0.0.1:5000/ (Press CTRL+C to quit)
 
 
+## Instance at LANCIS
+
+We're hosting an instance of this server at
+
+http://flock.apps.lancis.ecologia.unam.mx/
 

model.py

@@ -9,8 +9,6 @@ from LatLon23 import LatLon, Latitude, Longitude
 from geopy import distance
 
 
-# TODO: instead of centroid use speed and bearing of flockers to create a vector, point rider towards it
-# use time elapsed since last update, speed vector and current point to compute future location
 class Flock:
     """
     Flock object is created from a list of agents
@@ -92,17 +90,28 @@ class Bike(Document):
         return (self.destination[1],
                 self.destination[0])
 
-    def find_flock(self, point_altruism=0.1, dest_altruism=0.2):
+    def find_flock(self,
+                   point_altruism=0.1,
+                   dest_altruism=0.2,
+                   min_age=None):
         """
+        min_age of agents in database, in seconds
         :return: list of Bike objects
         """
 
+        if min_age is None:
+            min_step = 100   # update at least every 100 meters
+            if self.speed > 0:
+                min_age = min_step / self.speed
+            else:
+                min_age = 60
+        
         trip_len = distance.geodesic(self.get_point(), self.get_dest()).meters
 
         local_radius = trip_len * point_altruism
         destination_radius = trip_len * dest_altruism
 
-        # these are bikes around me
+        # these are bikes recently known to be around me
         local = [bike for bike in
                  self.db.bike.find(
                      {'point': {
@@ -112,7 +121,7 @@ class Bike(Document):
                                  'coordinates': self.point},
                              '$maxDistance': local_radius}},
                       'last_update': {
-                          '$gte': datetime.datetime.now() - datetime.timedelta(minutes=15)},  # TODO: adjust this
+                          '$gte': datetime.datetime.now() - datetime.timedelta(seconds=min_age)},
                       '_id': {'$ne': bson.objectid.ObjectId(self.id)}})]
 
         local_ids = set([bike['_id'] for bike in local])
@@ -124,7 +133,10 @@ class Bike(Document):
                           {'$near':
                             {'$geometry': {'type': 'Point',
                                            'coordinates': self.destination},
-                         '$maxDistance': destination_radius}}})]
+                             '$maxDistance': destination_radius}},
+                       'last_update': {
+                           '$gte': datetime.datetime.now() - datetime.timedelta(seconds=min_age)}
+                      })]
         remote_ids = set([bike['_id'] for bike in remote])
 
         # intersect them!

server.py

@@ -37,6 +37,10 @@ def update(bike_id):
     speed = float(request.args.get('speed', None))
     bearing = float(request.args.get('bearing', None))
 
+    local_altruism = float(request.args.get('local_altruism', 0.1))
+    dest_altruism = float(request.args.get('dest_altruism', 0.2))
+
+    
     bike.update(lat, lon, speed, bearing)
 
     return jsonify(