def edit_mask(self):
if not self.geom:
return
bbox = Polygon([[-180, 90], [180, 90], [180, -90], [-180, -90],
[-180, 90]])
mask = bbox.difference(self.geom)
return json.loads(mask.geojson)
def compute_chicago_marine_section():
mpoly = compute_chicago_region()
xmin, ymin, xmax, ymax = mpoly.extent
a = [(x, y) for (x, y) in mpoly.coords[0] if x == xmax]
b = [(x, y) for (x, y) in mpoly.coords[0] if y == ymax]
new_poly = Polygon([
(b[0][0], ymax),
(xmax, ymax),
(xmax, a[0][1]),
(b[0][0], a[0][1]),
(b[0][0], ymax),
])
return new_poly.difference(mpoly)
def compute_chicago_land_buffer():
mpoly = compute_chicago_region()
xmin, ymin, xmax, ymax = mpoly.extent
a = [(x, y) for (x, y) in mpoly.coords[0] if x == xmax]
b = [(x, y) for (x, y) in mpoly.coords[0] if y == ymax]
new_poly = Polygon([
(b[0][0], ymax),
(xmin, ymax),
(xmin, ymin),
(xmax, ymin),
mpoly.centroid.coords,
(b[0][0], ymax),
])
return new_poly.difference(mpoly)
