Unit test for the mapzen isolines

server/lib/python/cartodb_services/test/test_mapzenisolines.py

@@ -0,0 +1,76 @@
+import unittest
+from cartodb_services.mapzen import MapzenIsolines
+from math import radians, cos, sin, asin, sqrt
+
+"""
+This file is basically a sanity test on the algorithm.
+
+
+It uses a mocked client, which returns the cost based on a very simple model:
+just proportional to the distance from origin to the target point.
+"""
+
+class MatrixClientMock():
+
+    def __init__(self, speed):
+        """
+        Sets up the mock with a speed in km/h
+        """
+        self._speed = speed
+
+    def one_to_many(self, locations, costing):
+        origin = locations[0]
+        distances = [self._distance(origin, l) for l in locations]
+        response = {
+            'one_to_many': [
+                [
+                    {
+                        'distance': distances[i] * self._speed,
+                        'time': distances[i] / self._speed * 3600,
+                        'to_index': i,
+                        'from_index': 0
+                    }
+                    for i in xrange(0, len(distances))
+                ]
+            ],
+            'units': 'km',
+            'locations': [
+                locations
+            ]
+        }
+        return response
+
+    def _distance(self, a, b):
+        """
+        Calculate the great circle distance between two points
+        on the earth (specified in decimal degrees)
+        http://stackoverflow.com/questions/4913349/haversine-formula-in-python-bearing-and-distance-between-two-gps-points
+
+        Returns:
+            distance in meters
+        """
+
+        # convert decimal degrees to radians
+        lon1, lat1, lon2, lat2 = map(radians, [a['lon'], a['lat'], b['lon'], b['lat']])
+
+        # haversine formula
+        dlon = lon2 - lon1
+        dlat = lat2 - lat1
+        a = sin(dlat/2)**2 + cos(lat1) * cos(lat2) * sin(dlon/2)**2
+        c = 2 * asin(sqrt(a))
+        r = 6371 # Radius of earth in kilometers. Use 3956 for miles
+        return c * r
+
+
+class MapzenIsolinesTestCase(unittest.TestCase):
+
+    def setUp(self):
+        speed = 6 # in km/h
+        matrix_client = MatrixClientMock(speed)
+        self.mapzen_isolines = MapzenIsolines(matrix_client)
+
+    def test_calculate_isochrone(self):
+        origin = {"lat":40.744014,"lon":-73.990508}
+        transport_mode = 'walk'
+        isorange = 10 * 60 # 10 minutes
+        solution = self.mapzen_isolines.calculate_isochrone(origin, transport_mode, isorange)