问题
I am new at spatial analysis, but I cant find this answer anywhere.
I have a list of post codes in CRS coordinates, latitude and longitude, and London's Boroughs shape file in OSN coordinates, and I would like to map them together, but this is what happens. This is the head of the postcodes
london_post_codes.head()
Out[81]:
postcode latitude longitude
0 WD6 1GS 51.658021 -0.255663
1 WD17 1LA 51.660366 -0.397525
2 WC2N 6LE 51.509413 -0.121676
3 WC2N 6NA 51.508363 -0.124454
4 WC2N 6ND 51.508216 -0.123829
while this is the shape file read in geopandas
borough = gpd.read_file('London_Borough_Excluding_MHW.shp')
borough.head()
borough.head()
NAME GSS_CODE geometry
0 Kingston upon Thames E09000021 POLYGON ((516401.6 160201.8, 516407.3 160210.5...
1 Croydon E09000008 POLYGON ((535009.2 159504.7, 535005.5 159502, ...
2 Bromley E09000006 POLYGON ((540373.6 157530.4, 540361.2 157551.9...
3 Hounslow E09000018 POLYGON ((521975.8 178100, 521967.7 178096.8, ...
4 Ealing E09000009 POLYGON ((510253.5 182881.6, 510249.9 182886, ...
we can see how the coordinates of the polygons are different from those of the postcodes. I and when I plot them together I get
fig, ax = plt.subplots()
borough.plot(ax = ax)
borough = gpd.read_file('statistical-gis-boundaries-london/ESRI/London_Borough_Excluding_MHW.shp')
london_post_codes.plot(kind='scatter',s=10, x='longitude', y='latitude',ax=ax)
Any suggestions ?
回答1:
The solution is simply to change the CRS (Coordinate Reference System). These go by codes, which are called epsg. The lat/long CRS has a code of epsg=4326. Therefore
borough = gpd.read_file('London_Borough_Excluding_MHW.shp')
borough = borough.to_crs(epsg=4326)
and then the rest.
来源：https://stackoverflow.com/questions/47203938/convert-the-coordinates-of-a-shapefile-in-geopandas