def is_polygon_convex(polygon):
"""Determine if a polygon is convex.
Parameters
----------
polygon : sequence of sequence of floats
The XYZ coordinates of the corners of the polygon.
Notes
-----
Use this function for *spatial* polygons.
If the polygon is in a horizontal plane, use :func:`is_polygon_convex_xy` instead.
See Also
--------
is_polygon_convex_xy
"""
c = centroid_polygon(polygon)
for i in range(-1, len(polygon) - 1):
p0 = polygon[i]
p1 = polygon[i - 1]
p2 = polygon[i + 1]
v0 = subtract_vectors(c, p0)
v1 = subtract_vectors(p1, p0)
v2 = subtract_vectors(p2, p0)
a1 = angle_vectors(v1, v0)
a2 = angle_vectors(v0, v2)
if a1 + a2 > pi:
return False
return True
def center(self):
"""Point: The center (of mass) of the polygon."""
return Point(*centroid_polygon(self.points))