def station_split(osmdb, gtfsdb, split_threshold = 50, range = 0.005): # meters (max distance to link node), degrees (intersection box size)
split_idx = 1000000000 # base node/edge number. above usual OSM ids, but still leaves half of 32bit int range.
n_stops = gtfsdb.count_stops()
n_edges = osmdb.count_edges()
#edge_index = Rtree(osmdb_filename+'-edges')
edge_index = Rtree()
def index_subedge(rid, pair, edge_id) :
((s_lon, s_lat), (e_lon, e_lat)) = pair
box = (min(s_lon, e_lon), min(s_lat, e_lat), max(s_lon, e_lon), max(s_lat, e_lat))
# Need our own index number to remove edges as we go along.
# This index could ideally be generated automatically, with collision detection.
edge_index.add( rid, box, obj = (edge_id, pair) )
new_nodes = {} # for keeping track of where new nodes are added
print 'indexing OSM sub-way sub-edges into rtree'
progress = 0
for edge_id, way_id, from_nd, to_nd, dist, coords, tags in osmdb.edges() :
new_nodes [edge_id] = [] # an empty placeholder list to be filled in when new nodes are created along this edge
for subedge_number, pair in enumerate(cons(coords)) :
# make id the subedge number along the parent edge
index_subedge(subedge_number, pair, edge_id) # take first element because db response is a tuple
if progress % 1000 == 0 :
sys.stdout.write('\rEdge %d/%d' % (progress, n_edges))
sys.stdout.flush()
progress += 1
print
def nearest_point_on_subedge((subedge_rid, (edge_id, pair), subedge_bbox), stop_lat, stop_lon) :
# print "finding nearest point on edge %s (rtree id %d)" % (edge_id, edge_rid)
((s_lon, s_lat), (e_lon, e_lat)) = pair
# print (s_lat, s_lon, e_lat, e_lon, stop_lat, stop_lon)
stop = lg.GPoint(stop_lon, stop_lat)
ls = lg.LineString([(s_lon, s_lat), (e_lon, e_lat)], geographic=True)
dist = ls.distance_pt(stop)
pt = ls.closest_pt(stop)
loc = ls.locate_point(pt)
return subedge_rid, edge_id, pair, subedge_bbox, dist, pt, loc
# New nodes have been created as necessary. Delete old edges and add new ones between the new nodes.
print 'Removing old edges and adding new ones...'
progress=0
for edge_id, node_list in new_nodes.items() :
progress += 1
if progress % 100 == 0 :
sys.stdout.write('\rEdge %d/%d' % (progress, n_edges))
sys.stdout.flush()
if len(node_list) == 0 : continue
# get information about the edge to be replaced
edge_id, way_id, from_nd, to_nd, edge_length, coords, tags = osmdb.edge(edge_id)
# find distance and length for each sub-edge
subedges = []
c_dist = 0
for (lon1, lat1), (lon2, lat2) in cons(coords) :
dist = geoid_dist(lat1, lon1, lat2, lon2)
subedges.append((c_dist, dist))
c_dist += dist
print '\nedge: ', edge_id
print 'subedges: ', subedges
print 'new node list: ', node_list
# sort new nodes by subedge index and location within subedge
node_list.sort( key = lambda x: float(x[1]) + x[2] )
c = osmdb.cursor()
last_node_id = from_nd
dist = 0
subedge_idx = 0
while len(node_list) > 0 :
node_id, node_subedge, node_loc = node_list.pop(0) # take from beginning not end of list - otherwise sort is reversed.