def in_polygon(xpts, ypts, x_poly, y_poly, lib='mpl'):
"""
Find points inside an arbitraty polygon.
Given coordinates of 2D space (`xpts`, `ypts`), returns a
boolean array of the same size as `xpts` and `ypts` where
True values indicate coordinates inside the polygon
defined by (`x_poly`, `y_poly`). Setting the `lib` parameter
chooses to use tools from matplotlib.path or shapely.
Parameters
----------
xpts, ypts : array_like
Input coordinates.
x_poly, y_poly: array_like
Polygon coordinates.
lib : str
Library to use ('mpl' or 'shp')
Returns
-------
boolean array
True for points inside polygon.
"""
if lib == 'shp':
# Polygon border
poly = Polygon([(xp, yp) for (xp, yp) in zip(x_poly, y_poly)])
# Bool vector
boolean = [
poly.contains(Point(x_pt, y_pt))
for (x_pt, y_pt) in zip(xpts, ypts)
]
else:
# Set up input
pts = np.array([xpts, ypts]).T
poly = mpltPath.Path([[xp, yp] for (xp, yp) in zip(x_poly, y_poly)])
# Bool vector
boolean = poly.contains_points(pts)
return boolean
#open zip code file
pin_idx = {}
r = shp.Reader(plz)
print('Assigning coordinates to pin codes...')
for n,s in tqdm(enumerate(r.shapeRecords())):
pin = r.record(n)['plz']
poly = Polygon(s.shape.points)
x_i,y_i,x_j,y_j = poly.bounds
start = np.logical_and(np.greater_equal(points[:,0],x_i),np.less_equal(points[:,1], y_j))
end = np.logical_and(np.less_equal(points[:,0],x_j),np.greater_equal(points[:,1], y_i))
bidx = np.logical_and(start,end)
poly = Path(s.shape.points)
idx = poly.contains_points(points[bidx])
if pin in pin_idx.keys():
pin_idx[pin] += [*list(index[bidx][idx])]
else:
pin_idx[pin] = list(index[bidx][idx])
r.close()
#save state
w = shp.Writer('plz_nodes')
w.fields = [('plz','N',8,0)]
for pin,idx in pin_idx.items():
for i in idx:
w.point(*points[i])
