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# Author: Simon Blanke |
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# Email: [email protected] |
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# License: MIT License |
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import numpy as np |
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from ..base_optimizer import BaseOptimizer |
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from numpy.random import normal, laplace, logistic, gumbel |
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dist_dict = { |
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"normal": normal, |
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"laplace": laplace, |
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"logistic": logistic, |
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"gumbel": gumbel, |
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} |
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def max_list_idx(list_): |
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max_item = max(list_) |
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max_item_idx = [i for i, j in enumerate(list_) if j == max_item] |
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return max_item_idx[-1:][0] |
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class HillClimbingOptimizer(BaseOptimizer): |
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name = "Hill Climbing" |
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_name_ = "hill_climbing" |
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__name__ = "HillClimbingOptimizer" |
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optimizer_type = "local" |
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computationally_expensive = False |
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def __init__( |
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self, *args, epsilon=0.03, distribution="normal", n_neighbours=3, **kwargs |
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): |
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super().__init__(*args, **kwargs) |
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self.epsilon = epsilon |
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self.distribution = distribution |
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self.n_neighbours = n_neighbours |
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def move_climb(self, pos, epsilon_mod=1): |
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while True: |
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sigma = self.conv.max_positions * self.epsilon * epsilon_mod |
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pos_normal = dist_dict[self.distribution](pos, sigma, pos.shape) |
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pos = self.conv2pos(pos_normal) |
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if self.conv.not_in_constraint(pos): |
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return pos |
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epsilon_mod *= 1.01 |
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@BaseOptimizer.track_new_pos |
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@BaseOptimizer.random_iteration |
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def iterate(self): |
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return self.move_climb(self.pos_current) |
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@BaseOptimizer.track_new_score |
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def evaluate(self, score_new): |
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BaseOptimizer.evaluate(self, score_new) |
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if len(self.scores_valid) == 0: |
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return |
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modZero = self.nth_trial % self.n_neighbours == 0 |
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if modZero: |
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score_new_list_temp = self.scores_valid[-self.n_neighbours :] |
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pos_new_list_temp = self.positions_valid[-self.n_neighbours :] |
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idx = max_list_idx(score_new_list_temp) |
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score = score_new_list_temp[idx] |
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pos = pos_new_list_temp[idx] |
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self._eval2current(pos, score) |
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self._eval2best(pos, score) |
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