class and methods to compute the distance between two lat/lon pairs.

src/haversine.py

@@ -0,0 +1,44 @@
+"""
+Created on May 18, 2016
+
+@author: Paul Celicourt
+@email: [email protected]
+"""
+
+import math
+
+
+class Haversine(object):
+    def __init__(self):
+        self.earth_radius = 6373  # km
+
+    def convert_degree_to_radian(self, value_in_degree):
+        value_in_radian = math.radians(value_in_degree)
+        return value_in_radian
+
+    def compute_distance_between_lat_lon_pairs(self, origin_lat_lon_pair, destination_lat_lon_pair):
+
+        origin_latitude, origin_longitude = origin_lat_lon_pair
+        destination_latitude, destination_longitude = destination_lat_lon_pair
+
+        assert (-180 <= origin_longitude <= 180)
+        assert (-180 <= destination_longitude <= 180)
+        assert (-90 <= origin_latitude <= 90)
+        assert (-90 <= destination_latitude <= 90)
+
+        origin_latitude_in_radian = math.radians(origin_latitude)
+        origin_longitude_in_radian = math.radians(origin_longitude)
+        destination_latitude_in_radian = math.radians(destination_latitude)
+        destination_longitude_in_radian = math.radians(destination_longitude)
+
+        latitude_difference_in_radian = destination_latitude_in_radian - origin_latitude_in_radian
+        longitude_difference_in_radian = destination_longitude_in_radian - origin_longitude_in_radian
+
+        haversine_of_central_angle = (math.sin(latitude_difference_in_radian/2))**2 + \
+                                     math.cos(destination_latitude_in_radian) * math.cos(origin_latitude_in_radian) * \
+                                     (math.sin(longitude_difference_in_radian/2))**2
+
+        central_angle = 2 * math.atan2(math.sqrt(haversine_of_central_angle), math.sqrt(1-haversine_of_central_angle))
+        distance_between_lat_lon_pairs = self.earth_radius * central_angle
+
+        return distance_between_lat_lon_pairs

src/testshaversine.py

@@ -0,0 +1,22 @@
+"""
+Created on May 18, 2016
+
+@author: Paul Celicourt
+@email: [email protected]
+"""
+
+import unittest
+
+from haversine import Haversine
+
+class HaversineSuperTest(unittest.TestCase):
+
+    def setUp(self):
+        self.harversine_object = Haversine()
+
+
+class HaversineTest(HaversineSuperTest):
+    def test_compute_distance_between_lat_lon_pairs(self):
+        distance = self.harversine_object.compute_distance_between_lat_lon_pairs((52.2296756,21.0122287),
+                                                                                 (52.406374,16.9251681))
+        self.assertAlmostEqual(distance, 278.545589351, 3)