test script for determining neighbor cell ids to send to pokemon go api for location requests

neighbor_test.py

import sys
import math
from s2sphere import CellId, LatLng, LatLngRect, Cell

def getNeighbors():
  origin = CellId.from_lat_lng(LatLng.from_degrees(FLOAT_LAT, FLOAT_LONG)).parent(15)
 
  walk = [origin.id()]
  
  #get the 8 neighboring cells
  path = [90,180,270,270,0,0,90,90]

  origin_lat = FLOAT_LAT
  origin_lng = FLOAT_LONG
  
  R = 6379.1 #earth
  for direction in path:
    bearing = math.radians(direction)
    #choose a distance based on direction to get us into the adjoining cell
    if direction in [0, 180]:
      distance = 0.305 #approx distance in km from centroid of cell to next NS cell centroid
    elif direction in [90,270]:
      distance = 0.213 #approx distance in km from centroid of cell to next EW cell centroid

    lat1 = math.radians(origin_lat)
    lng1 = math.radians(origin_lng)

    lat2 = math.asin( math.sin(lat1)*math.cos(distance/R) +
      math.cos(lat1)*math.sin(distance/R)*math.cos(bearing))
    lng2 = lng1 + math.atan2(math.sin(bearing)*math.sin(distance/R)*math.cos(lat1),
      math.cos(distance/R)-math.sin(lat1)*math.sin(lat2))
    
    lat2 = math.degrees(lat2)
    lng2 = math.degrees(lng2)
 
    new_cell = CellId.from_lat_lng(LatLng.from_degrees(lat2, lng2)).parent(15)
    walk.append(new_cell.id())

    origin_lat = lat2
    origin_lng = lng2
  
  #be sure that whatever walk length is here that you set the length of f2 in the request to be the same
  return walk


if __name__ == '__main__':
   FLOAT_LAT, FLOAT_LONG = map(float, sys.argv[1:])
   print "id,latitude,longitude"
   count = 0
   for c in getNeighbors():
     cell = CellId(c)
     cell_ll = cell.to_lat_lng()
     lat = math.degrees(cell_ll.lat().radians)
     lng = math.degrees(cell_ll.lng().radians)
     
     print ','.join(map(str, [count, lat, lng]))
  
     count += 1