Enclaves#

[3]:

%matplotlib widget
import geopandas
import pandas
import starepandas
import pystare
import shapely
import matplotlib.pyplot as plt

[4]:

level = 8

[5]:

world = geopandas.read_file(geopandas.datasets.get_path('naturalearth_lowres'))
rsa = world[world.name=='South Africa']
rsa = starepandas.STAREDataFrame(rsa, add_sids=True, level=level, add_trixels=True)

[6]:

rsa.set_geometry(rsa._trixel_column_name, inplace=False)

[6]:

	pop_est	continent	name	iso_a3	gdp_md_est	geometry	sids	trixels
25	58558270.0	Africa	South Africa	ZAF	351431	POLYGON ((16.34498 -28.57671, 16.82402 -28.082...	[2814749767106567, 2858730232217608, 286752632...	MULTIPOLYGON (((18.95439 -31.03247, 18.31675 -...

[7]:

len(rsa.sids.iloc[0])

[7]:

[9]:

# Just to verify if simplification is OK
fig, ax = plt.subplots(dpi=100, figsize=(14,9))
ax.grid(True)

rsa.plot(ax=ax, trixels=True, boundary=True, color='y', zorder=0)
rsa.plot(ax=ax, trixels=False, facecolor="none", edgecolor='blue', lw=1, zorder=1)
fig.tight_layout()

#plt.savefig('lesotho.png')

[7]:

rsa.trixels

[7]:

25    MULTIPOLYGON (((18.95439 -31.03247, 18.31675 -...
Name: trixels, dtype: geometry

Exterior#

[8]:

exterior = rsa.iloc[0].geometry.exterior
sids_ext = starepandas.sids_from_ring(exterior, level=level, force_ccw=True)
df_ext = starepandas.STAREDataFrame(sids=sids_ext, add_trixels=True)
df_ext.plot(trixels=True)

[8]:

<AxesSubplot:>

../../_images/examples_notebooks_enclaves_9_1.png

Interior CCW#

[9]:

interiors = rsa.iloc[0].geometry.interiors
sids_int = starepandas.sids_from_ring(interiors[0], level=level, force_ccw=True)
df_int = starepandas.STAREDataFrame(sids=sids_int, add_trixels=True)
df_int.plot(trixels=True)

[9]:

<AxesSubplot:>

../../_images/examples_notebooks_enclaves_11_1.png

Interior CW#

[10]:

int_inv = interiors[0]
int_inv = shapely.geometry.polygon.LinearRing(int_inv.coords[::-1])
sids_int_inv = starepandas.sids_from_ring(int_inv, level=level, force_ccw=False)
df_int = starepandas.STAREDataFrame(sids=sids_int_inv, add_trixels=True)
df_int.plot(trixels=True)

[10]:

<AxesSubplot:>

../../_images/examples_notebooks_enclaves_13_1.png

Combine#

[11]:

sids_hole = pystare.intersect(sids_int_inv, sids_ext)
df_int = starepandas.STAREDataFrame(sids=sids_hole, add_trixels=True)
df_int.plot(trixels=True)

[11]:

<AxesSubplot:>

../../_images/examples_notebooks_enclaves_15_1.png

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