<|file_name|>haversine.py<|end_file_name|><｜fim▁begin｜>from math import radians, cos, sin, asin, sqrt

def <|fim_middle|>(lon1, lat1, lon2, lat2):
    """
    Calculate the great circle distance between two points
    on the earth (specified in decimal degrees)
    """
    # convert decimal degrees to radians
    lon1, lat1, lon2, lat2 = map(radians, [lon1, lat1, lon2, lat2])

    # 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))

    # 6367 km is the radius of the Earth
    km = 6367 * c
    return km
<｜fim▁end｜>
haversine