def create_oracle(mpc, set_vrep, abs_frac, abs_err, rel_err):
"""
Creates the optimization problem oracle.
Parameters
----------
mpc : MPC
The control law to be used.
set_vrep : np.array
Vertex representation of the set to be partitioned (every row is a
vertex).
abs_frac : float, optional
Fraction (0,1) away from the origin of the full size of the invariant
set where to compute the absolute error.
abs_err : float, optional
Absolute error value. If provided, takes precedence over abs_frac.
rel_err : float
Relative error value.
Returns
-------
oracle : Oracle
Optimization problem oracle.
"""
if abs_err is None:
oracle = Oracle(mpc, eps_a=1., eps_r=1.)
abs_err = np.max([
oracle.P_theta(theta=vx)[2]
for vx in [abs_frac * vx for vx in set_vrep]
])
oracle = Oracle(mpc, eps_a=abs_err, eps_r=rel_err)
return oracle
