Python で緯度と経度の座標間の距離をすばやく計算するにはどうすればよいですか?

<code class="python">import numpy as np

def haversine_np(lon1, lat1, lon2, lat2):
    """
    Calculate the great circle distance between two points
    on the earth (specified in decimal degrees)

    All args must be of equal length.    

    """
    lon1, lat1, lon2, lat2 = map(np.radians, [lon1, lat1, lon2, lat2])

    dlon = lon2 - lon1
    dlat = lat2 - lat1

    a = np.sin(dlat/2.0)**2 + np.cos(lat1) * np.cos(lat2) * np.sin(dlon/2.0)**2

    c = 2 * np.arcsin(np.sqrt(a))
    km = 6378.137 * c
    return km</code>

<code class="python">df = pd.DataFrame(...your_dataframe...)
lon1, lat1, lon2, lat2 = df['lon1'], df['lat1'], df['lon2'], df['lat2']
df['distance'] = haversine_np(lon1, lat1, lon2, lat2)</code>