def get_circumscribed_ellipsoid(self):
"""
Return a circumscribed ellipsoid of the cylinder.
"""
semiaxes = np.array(3 * [np.sqrt(2.0) * self.radius], dtype=np.float64)
semiaxes[2] *= self.length_to_width
mtx = np.diag(1.0 / (semiaxes**2))
return mtx
def __contains__(self, point):
"""
Point x in cylinder.
"""
x = point - self.centre
aux = np.dot(self.rot_mtx, x)
r = np.sqrt(aux[0]**2 + aux[1]**2)
val = (np.abs(aux[2]) <= self.height) & (r <= self.radius)
return val
def get_origin_bounding_box(self):
"""
Get the ellipsoid's axes-aligned bounding box as if centered at the
origin.
Return:
bbox : 3 x 2 array
The bounding box.
"""
aux = np.sqrt(np.diag(inv(self.mtx)))[:, np.newaxis]
return np.c_[-aux, aux]
def get_origin_bounding_box(self):
"""
Get the ellipsoid's axes-aligned bounding box as if centered at the
origin.
Return:
bbox : 3 x 2 array
The bounding box.
"""
aux = np.sqrt(np.diag(inv(self.mtx)))[:,np.newaxis]
return np.c_[-aux, aux]
def contains(self, points):
"""
Point x in cylinder. Works for array of points.
Parameters
----------
points : (n_point, 3) array
The points to be tested for inclusion.
"""
points = np.array(points, ndmin=2, dtype=np.float64)
x = points.T - self.centre[:,np.newaxis]
aux = np.dot(self.rot_mtx, x)
r = np.sqrt(aux[0,:]**2 + aux[1,:]**2)
mask = (np.abs(aux[2,:]) <= (0.5 * self.height)) & (r <= self.radius)
return mask
def get_radius(self):
r = np.sqrt((0.5 * self.height)**2 + self.radius**2)
return r