PDL : heuristic functions implementation and test

app/travel_resolver/libs/pathfinder/heuristic.py

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+import math
+
+def euclidean_distance(lat1 : float, lon1 : float, lat2 : float, lon2 : float):
+    """
+    Calculate the Euclidean distance between two points given by their latitudes and longitudes.
+    The coordinates are in degrees.
+    Args:
+            lat1 (float): Latitude of the first point.
+            lon1 (float): Longitude of the first point.
+            lat2 (float): Latitude of the second point.
+            lon2 (float): Longitude of the first point.
+
+        Returns:
+            (float): The Euclidean distance (radians) between the two points.
+    """
+    # Conversion des degrés en radians
+    lat1, lon1 = math.radians(lat1), math.radians(lon1)
+    lat2, lon2 = math.radians(lat2), math.radians(lon2)
+    
+    # Différence des coordonnées
+    delta_lat = lat2 - lat1
+    delta_lon = lon2 - lon1
+    
+    # Distance euclidienne (approximation plane)
+    distance = math.sqrt(delta_lat**2 + delta_lon**2)
+    
+    return distance
+
+def haversine_distance(lat1 : float, lon1 : float, lat2 : float, lon2 : float):
+    """
+    Calculates the distance as the crow flies between two points on the Earth
+    (coordinates specified in degrees) using the Haversine formula.
+    Args:
+            lat1 (float): Latitude of the first point.
+            lon1 (float): Longitude of the first point.
+            lat2 (float): Latitude of the second point.
+            lon2 (float): Longitude of the first point.
+
+        Returns:
+            (float): The distance as the crow flies (kilometers) between the two points.
+    """
+    # Rayon de la Terre en kilomètres
+    R = 6371.0
+    
+    # Conversion des degrés en radians
+    lat1, lon1 = math.radians(lat1), math.radians(lon1)
+    lat2, lon2 = math.radians(lat2), math.radians(lon2)
+    
+    # Différences des coordonnées
+    delta_lat = lat2 - lat1
+    delta_lon = lon2 - lon1
+    
+    # Formule de haversine
+    a = math.sin(delta_lat / 2)**2 + math.cos(lat1) * math.cos(lat2) * math.sin(delta_lon / 2)**2
+    c = 2 * math.atan2(math.sqrt(a), math.sqrt(1 - a))
+    
+    # Distance à vol d'oiseau
+    distance = R * c
+    
+    return distance

app/travel_resolver/tests/heuristic_test.py

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+import unittest
+from travel_resolver.libs.pathfinder.heuristic import euclidean_distance,haversine_distance
+
+class TestHeuristic(unittest.TestCase):
+
+    def setUp(self):
+        self.latParis, self.lonParis = 48.8566, 2.3522
+        self.latLyon, self.lonLyon = 45.7640, 4.8357
+
+    def test_euclidian_distance(self):
+        expected_distance = 0.06922589910147367
+        distance = euclidean_distance(self.latParis, self.lonParis, self.latLyon, self.lonLyon)
+        self.assertEqual(distance, expected_distance)
+
+    def test_haversin_distance(self):
+        expected_distance = 391.4989316742569
+        distance = haversine_distance(self.latParis, self.lonParis, self.latLyon, self.lonLyon)
+        self.assertEqual(distance, expected_distance)
+
+if __name__ == '__main__':
+    unittest.main()