Function distance

tools/python/openlr/quality.py:14–29

Implements https://en.wikipedia.org/wiki/Haversine_formula. >>> int(distance(LatLon(55.747043, 37.655554), LatLon(55.754892, 37.657013))) 875 >>> int(distance(LatLon(60.013918, 29.718361), LatLon(59.951572, 30.205536))) 27910

(x, y)

LatLon = namedtuple('LatLon', 'lat, lon')

def distance(x, y):
    """Implements https://en.wikipedia.org/wiki/Haversine_formula.

    >>> int(distance(LatLon(55.747043, 37.655554), LatLon(55.754892, 37.657013)))
    875
    >>> int(distance(LatLon(60.013918, 29.718361), LatLon(59.951572, 30.205536)))
    27910
    """

    φ1, φ2 = map(radians, [x.lat, y.lat])
    λ1, λ2 = map(radians, [x.lon, y.lon])
    Δφ = φ2 - φ1
    Δλ = λ2 - λ1
    a = sin(Δφ/2)**2 + cos(φ1) * cos(φ2) * sin(Δλ/2)**2
    R = 6356863  # Earth radius in meters.
    return 2 * R * atan2(sqrt(a), sqrt(1 - a))

def lcs(l1, l2, eq=operator.eq):
    """Finds the longest common subsequence of l1 and l2.