如何使用地ge以查找最近几何索引

Question

这是如何查找最近几何的索引。我需要在geopandas df target_df中找到geopandas df source> source_df中的每个点的最接点。我可以使用shapely进行此操作，但是当我尝试应用使用geopandas的代码时，我会得到此错误'typeerror：不可用的类型：'geodataframe'。代码如下：

import geopandas as gpd
import shapely

# Return the field COLUMN of the nearest point in TARGET_DF to each point in SOURCE_DF

def nearest(source_df, target_df, trg_column=None):

    # Merge target DF points into MultiPoint object
    
    mpts = target_df.geometry.unary_union         
    
    # Find the closest point
    
    curr_pt, near_pt = shapely.ops.nearest_points(source_df['geometry'], mpts)
    nearest = target_df['geometry'] == near_pt
    
    # Get the corresponding value from TARGET_DF
    
    value = target_df[nearest][trg_column].values[0]
    
    return value

# MAIN program

if __name__ =="__main__":
    
    # Define dataframe of target points
    
    df_targ = gpd.GeoDataFrame([['point A', shapely.geometry.Point(1,1)], 
                                ['point B', shapely.geometry.Point(2,2)],
                                ['point C', shapely.geometry.Point(3,3)],
                                ['point D' ,shapely.geometry.Point(4,4)]], 
                                 columns=['t_name', 'geometry'])
    
    # Define points to process and store in GeoPandas DF
    
    dx = 0.1
    dy = 0.1
    
    pt_list = []
    for indx, pt in enumerate(df_targ['geometry']):
        new_pt = shapely.geometry.Point(pt.x + dx, pt.y + dy)
        nname = "target_%1d" % indx 
        pt_list.append([nname, new_pt])
    
    df_sorc = gpd.GeoDataFrame(pt_list, columns=['s_name', 'geometry'])
    
    # Find nearest point using shapely
    
    mpts = df_targ.geometry.unary_union         # Merge DF points into MultiPoint object
    
    print("Using shapely:")
    for pt in df_sorc['geometry']:
        curr_pt, near_pt = shapely.ops.nearest_points(pt, mpts)
    
        near_nam = df_targ.loc[df_targ['geometry'] == near_pt, 't_name'].values[0]
        print("nearest point to (%3.1f, %3.1f) is %s" % (pt.x, pt.y, near_nam))
    
    # Find nearest point using Geopandas
    
    df_sorc['nearest_pt'] = df_sorc.apply(nearest, df_targ, trg_column='t_name')
    print(df_sorc.head())

我尝试更改Apply语句如下：

    df_sorc['nearest_pt'] = df_sorc.apply(nearest, df_targ, trg_column='t_name', axis=1)

但是现在获取此错误：typeError：apply（）获得了参数'axis''的多个值。感谢任何建议。提前致谢

Answer 1

我在这里找到答案：
set_axis（）获得了参数'axis'axis'>的多个值。问题似乎是pandas更改了版本0.21.0中的应用函数的参数顺序。我将应用语句更改为

df_sorc['nearest_pt'] = df_sorc.apply(nearest, axis=1, trg_df=df_targ, trg_col='t_name')

“应用”功能以

def nearest(source_df, trg_df=None, trg_col=None):

避免位置参数问题。这给出了预期的行为