import pyproj

def distance(lat1, lng1, lat2, lng2, ellps = 'WGS84'):
    g = pyproj.Geod(ellps = ellps)
    return g.inv(lng1, lat1, lng2, lat2)[2]

def distance_between(p1, p2):
    return distance(p1[0], p1[1], p2[0], p2[1])

def nearest_mile(distance_in_metres):
    return int(0.621371*distance_in_metres/1000)

def total_distance(points):
    return sum(map(distance_between, points[:-1], points[1:]))

p1 = (52.9548, -1.1581)   # Nottingham, England
p2 = (38.253284, -85.758786)   # Louisville, KY
print "Distance (to the nearest mile): " + str(nearest_mile(distance_between(p1, p2)))

data_dir_path = '/home/matthew/workspace/resources/G/Geographical Information Science/'
van_activity_csv_filename = 'van_activity.csv'
van_activity_csv_filename = 'gps-activity.csv'
van_activity_csv_path = data_dir_path + van_activity_csv_filename
labels = ['id','van_id','timestamp','latitude','longitude','type','address','speed','heading','created']

import csv

csv_file = open(van_activity_csv_path, 'rb')
van_activity_reader = csv.DictReader(csv_file, labels, delimiter=',', quotechar='\"')

van_activity_reader.next()
points = []
for van_activity in van_activity_reader:
    points.append((van_activity['latitude'], van_activity['longitude']))

len(points)

print "Distance (to the nearest mile): " + str(nearest_mile(total_distance(points)))