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pythongoogle-mapsgoogle-maps-api-3closest

How would I find the closest place Python and the Google Maps API


I have this program in which I want it to return a few places from a list, in order of which is closest to a set point with longitude and latitude. I want it to return, for example, the five closest places that are in my list of tuples of longs and lats, in order, to the set point. I am doing this with Python.


Solution

  • Using: Haversine, you can just do:

    from math import radians, cos, sin, asin, sqrt
    
    center = (lon, lat)
    points = [(lon1, lat1), (lon2, lat2), (lon3, lat3), (lon4, lat4), (lon5, lat5))
    altogether = [list(center) + list(item) for item in points]
    
    def haversine(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)) 
        r = 6371 # Radius of earth in kilometers. Use 3956 for miles
        return c * r
    
    distances = list(map(lambda a: haversine(*a), altogether))