def get_difference(poly1, poly2, pixels=None):
"""attempt to get the difference poly1-poly2 as poly1^~poly2
use a pixelation to attempt to find an outside point"""
import matplotlib.pyplot as plt
from mpl_toolkits.basemap import Basemap
m = Basemap(projection='moll', lon_0=0)
if pixels is None:
pixels = get_healpix_pixelation(4)
bounding_xyz = list(poly2.points)
#contained = np.zeros(pixels.shape[0],dtype==bool)
#for itr in range(0,len(bounding_xyz)):
# ra,dec = sgv.vector_to_radec(
# contained = contained | contains_points(bounding_xyz[itr],pixels)
contained = contains_points(pixels, poly2)
poly2_complement = None
#poly2_complement = poly2.invert_polygon()
#contained_c = contains_points(pixels,poly2_complement)
#assert not np.any(contained & contained_c)
first_false = 100 + np.argmin(contained[100:])
#print("orig 1",contains_points(pixels[first_false:first_false+1],poly1),poly1.area())
#print("orig 2",contains_points(pixels[first_false:first_false+1],poly2),poly2.area())
print(poly2)
colors = ['red', 'green', 'blue']
for itr in range(0, len(bounding_xyz)):
first_false = 100 + itr + np.argmin(contained[100 + itr:])
theta_in = pixels[first_false, 0]
phi_in = pixels[first_false, 1]
inside_xyz = np.asarray(
sgv.radec_to_vector(phi_in, theta_in - np.pi / 2., degrees=False))
loc_poly = SphericalPolygon(bounding_xyz[itr].copy(),
inside_xyz.copy())
loc_poly.draw(m, color=colors[itr])
cont = contains_points(pixels[first_false:first_false + 1], loc_poly)
print("loc contains: ", cont)
if poly2_complement is None:
poly2_complement = deepcopy(loc_poly)
else:
poly2_complement = deepcopy(
poly2_complement.intersection(loc_poly))
cont_comp = contains_points(pixels[first_false:first_false + 1],
poly2_complement)
print("comp contains: ", cont_comp)
print("test: ",
np.all(contains_points(pixels[contained], poly2_complement)))
print("test: ",
np.any(contains_points(pixels[~contained], poly2_complement)))
print("insp: ", list(poly2_complement.inside))
#print("comp ",itr,contains_points(pixels[first_false:first_false+1],poly2_complement),poly2_complement.area(),poly2_complement.is_clockwise())
#print("inside c ",list(poly2_complement.inside))
#print("vert c ",list(poly2_complement.points))
#for itr2 in range(0,len(list(poly2_complement.inside))):
# print("loc cont inside c ",loc_poly.contains_point(list(poly2_complement.inside)[itr2]))
#print(poly1.area(),poly2.area(),poly2_complement.area())
plt.show()
return poly1.intersection(poly2_complement)
