GeoPandas Label Polygons
Given the shape file available here: I'd like to label each polygon (county) in the map. Is this possible with GeoPandas?
import geopandas as gpd
import matplotlib.pyplot as plt
%matplotlib inline
shpfile=<Path to unzipped .shp file referenced and linked above>
c=gpd.read_file(shpfile)
c=c.loc[c['GEOID'].isin(['26161','26093','26049','26091','26075','26125','26163','26099','26115','26065'])]
c.plot()
Thanks in advance!
c['geometry']
is a series comprised of shapely.geometry.polygon.Polygon
objects. You can verify this by checking
In [23]: type(c.ix[23, 'geometry'])
Out[23]: shapely.geometry.polygon.Polygon
From the Shapely docs there is a method representative_point()
that
Returns a cheaply computed point that is guaranteed to be within the geometric object.
Sounds ideal for a situation in which you need to label the polygon objects! You can then create a new column for your geopandas
dataframe
, 'coords'
like so
c['coords'] = c['geometry'].apply(lambda x: x.representative_point().coords[:])
c['coords'] = [coords[0] for coords in c['coords']]
Now that you have a set of coordinates pertaining to each polygon object (each county), you can annotate your plot by iterating through your dataframe
c.plot()
for idx, row in c.iterrows():
plt.annotate(s=row['NAME'], xy=row['coords'],
horizontalalignment='center')
no need to loop, here is how you can annotate with apply:
ax = df.plot()
df.apply(lambda x: ax.annotate(text=x['NAME'], xy=x.geometry.centroid.coords[0], ha='center'), axis=1);