I'm currently transferring from ESRI to open source GIS by recreating basic ArcGIS tasks in Python, mainly using Geopandas since I have some experience with Pandas.
Now I'm trying to intersect a Building_Footprint shapefile with a one-mile buffer of a point.
The input data:
Building footprint:
Center point around which the buffer is made:
center=pd.DataFrame({ 'Lat':[40.603155], 'Lon':[-75.478003]})
center_g = [Point(xy) for xy in zip(center.Lon, center.Lat)]
cg = gpd.GeoDataFrame(center, geometry=center_g)
cg.crs = {'init' :'epsg:4326'}
cg = cg.to_crs(bldg.crs)
And then I made a one-mile buffer around the center:
cg.buffer(5280) #The map unit is ft hence the number 5280
Now this is where I'm stuck. I'm trying to intersect the buffer with the bldg GeoDataFrame. So I tried this:
bldg1 = bldg.unary_union
to convert bldg to a single feature so it may be faster. But it takes forever since there are more than 160K records in bldg.
I've spend quite a lot of time on this task while it could be easily done in ArcGIS. I'm wondering what's the best way to go at it.
cg.buffer(5280)step, the result will be a single object hence a shapely object. Can I still use it as input forgeopandas.overlay? I feel like there is much restriction on single shapely objects. Thanks again. – Bowen Liu Apr 24 '19 at 18:58gpd.GeoDataFrame(crs=bldg.crs? I'm having trouble with my projection system as well. If you care to take a look: https://gis.stackexchange.com/questions/320757/coordinate-system-shows-up-incorrect-after-converting-a-shapely-object-to-a-shap – Bowen Liu Apr 24 '19 at 19:16to_crsis actually projected coordinate system. I guess it's the actual geospatial system. How to specify a projected coordinate system then? Getting stuck in coordinate system is my worst trouble, I shall just use WGS84 for both files. But then how shall I specify buffer radius? Degree is a headache compare to usual length unit. Thanks. – Bowen Liu Apr 24 '19 at 19:24