fancy_gym/alr_envs/stochastic_search/functions/f_base.py

77 lines
2.5 KiB
Python

import numpy as np
import scipy.stats as scistats
np.seterr(divide='ignore', invalid='ignore')
class BaseObjective(object):
def __init__(self, dim, int_opt=None, val_opt=None, alpha=None, beta=None):
self.dim = dim
self.alpha = alpha
self.beta = beta
# check if optimal parameter is in interval...
if int_opt is not None:
self.x_opt = np.random.uniform(int_opt[0], int_opt[1], size=(1, dim))
# ... or based on a single value
elif val_opt is not None:
self.one_pm = np.where(np.random.rand(1, dim) > 0.5, 1, -1)
self.x_opt = val_opt * self.one_pm
else:
raise ValueError("Optimal value or interval has to be defined")
self.f_opt = np.round(np.clip(scistats.cauchy.rvs(loc=0, scale=100, size=1)[0], -1000, 1000), decimals=2)
self.i = np.arange(self.dim)
self._lambda_alpha = None
self._q = None
self._r = None
def __call__(self, x):
return self.evaluate_full(x)
def evaluate_full(self, x):
raise NotImplementedError("Subclasses should implement this!")
def gs(self):
# Gram Schmidt ortho-normalization
a = np.random.randn(self.dim, self.dim)
b, _ = np.linalg.qr(a)
return b
# TODO: property probably unnecessary
@property
def q(self):
if self._q is None:
self._q = self.gs()
return self._q
@property
def r(self):
if self._r is None:
self._r = self.gs()
return self._r
@property
def lambda_alpha(self):
if self._lambda_alpha is None:
if isinstance(self.alpha, int):
lambda_ii = np.power(self.alpha, 1 / 2 * self.i / (self.dim - 1))
self._lambda_alpha = np.diag(lambda_ii)
else:
lambda_ii = np.power(self.alpha[:, None], 1 / 2 * self.i[None, :] / (self.dim - 1))
self._lambda_alpha = np.stack([np.diag(l_ii) for l_ii in lambda_ii])
return self._lambda_alpha
@staticmethod
def f_pen(x):
return np.sum(np.maximum(0, np.abs(x) - 5), axis=1)
def t_asy_beta(self, x):
# exp = np.power(x, 1 + self.beta * self.i[:, None] / (self.input_dim - 1) * np.sqrt(x))
# return np.where(x > 0, exp, x)
return x
def t_osz(self, x):
x_hat = np.where(x != 0, np.log(np.abs(x)), 0)
c_1 = np.where(x > 0, 10, 5.5)
c_2 = np.where(x > 0, 7.9, 3.1)
return np.sign(x) * np.exp(x_hat + 0.049 * (np.sin(c_1 * x_hat) + np.sin(c_2 * x_hat)))