python - 半正弦函数的 Python 数学库中出现错误

Question

我试图找到两个地理纬度和经度之间的距离

我用必要的公式创建了一个函数半正弦函数:

from math import radians,cos,sin,asin,sqrt
def haversine(lon1,lat1,lon2,lat2):
    #convert decimals to radians
    lon1,lat1,lon2,lat2=map(radians,[lon1,lat1,lon2,lat2])
    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

haversine(-97.481,-97.622,-74.1083,-74.106)

现在我想找到我的 df 中的点的距离，以及它们是否在泽西市经纬度 50 公里半径内:

import pandas as pd

df = pd.DataFrame({'Company':['WM','WS','WC','WW'],
                   'city':['Norman','OKC','NY','Bayonne'],
                   'latitude':[35.221,35.463,41.112,40.66],
                   'longtitude':[-97.481,-97.622,-74.1083,-74.106]})

jersey_city_lat_lon=(40.94,-74.05)
df['distance']=df.apply(haversine,args=(jersey_city_lat_lon),axis=1)
df[df['distance']<=100]

但是，当我运行上述命令时，我收到错误:

Traceback (most recent call last):

  File "<ipython-input-123-8d33df9e0fab>", line 7, in <module>
    df['distance']=df.apply(haversine,args=(jersey_city_lat_lon),axis=1)

  File "C:\Users\j\AppData\Local\Continuum\anaconda3\lib\site-packages\pandas\core\frame.py", line 6487, in apply
    return op.get_result()

  File "C:\Users\j\AppData\Local\Continuum\anaconda3\lib\site-packages\pandas\core\apply.py", line 151, in get_result
    return self.apply_standard()

  File "C:\Users\j\AppData\Local\Continuum\anaconda3\lib\site-packages\pandas\core\apply.py", line 257, in apply_standard
    self.apply_series_generator()

  File "C:\Users\j\AppData\Local\Continuum\anaconda3\lib\site-packages\pandas\core\apply.py", line 286, in apply_series_generator
    results[i] = self.f(v)

  File "C:\Users\j\AppData\Local\Continuum\anaconda3\lib\site-packages\pandas\core\apply.py", line 78, in f
    return func(x, *args, **kwds)

TypeError: ("haversine() missing 1 required positional argument: 'lat2'", 'occurred at index 0')

它应该可以工作并显示一个位置在纽约，另一个位置在巴约讷，它在我们正在寻找的半径内，因为纽约和巴约讷都位于距泽西城 50 公里的径向距离内。为什么我会收到此错误？

Answer 1

df.apply 将行对象(或 axis=0 的列)传递给目标函数。它不知道将行解压到您想要的字段中。您可以包装 hasrsign 函数以仅提取纬度和经度列

jersey_city_long_lat=(-74.05,40.94)
def row_hsign(row):
    return haversine(*jersey_city_long_lat,row['longtitude'],row['latitude'])

df['distance']=df.apply(row_hsign,axis=1)