def load_pace_vectors(dates, consistent_link_set):
# Map (begin_node,connecting_node) --> ID in the pace vector
link_id_map = defaultdict(lambda : -1) # -1 indicates an invalid ID number
for i in xrange(len(consistent_link_set)):
key = consistent_link_set[i]
link_id_map[key] = i
db_main.connect('db_functions/database.conf')
vects = []
weights = []
for date in dates:
# Initialize to zero
vect = matrix(zeros((len(consistent_link_set), 1)))
weight = matrix(zeros((len(consistent_link_set), 1)))
# Get the travel times for this datetime
curs = db_travel_times.get_travel_times_cursor(date)
# Assign travel times into the vector, if this link is in the consistant link set
for (begin_node_id, end_node_id, date_time, travel_time, num_trips) in curs:
i = link_id_map[begin_node_id, end_node_id] # i will be -1 if the link is not in the consistant link set
if(i>=0):
vect[i] = travel_time
weight[i] = num_trips
vects.append(vect)
weights.append(weight)
db_main.close()
return vects, weights
def compute_link_counts(dates):
num_obs = defaultdict(float)
num_appearances = defaultdict(float)
db_main.connect('db_functions/database.conf')
for date in dates:
curs = db_travel_times.get_travel_times_cursor(date)
for [begin_node_id, end_node_id, date_time, travel_time, num_trips] in curs:
num_obs[begin_node_id, end_node_id] += num_trips
num_appearances[begin_node_id, end_node_id] += 1
db_main.close()
return num_obs, num_appearances
