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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_population_optimizer import BasePopulationOptimizer |
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from ...search import Search |
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from ._particle import Particle |
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class ParticleSwarmOptimizer(BasePopulationOptimizer, Search): |
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def __init__( |
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self, |
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search_space, |
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inertia=0.5, |
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cognitive_weight=0.5, |
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social_weight=0.5, |
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temp_weight=0.2, |
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rand_rest_p=0.03, |
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): |
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super().__init__(search_space) |
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self.inertia = inertia |
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self.cognitive_weight = cognitive_weight |
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self.social_weight = social_weight |
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self.temp_weight = temp_weight |
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self.rand_rest_p = rand_rest_p |
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self.particles = self.optimizers |
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def _sort_best(self): |
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scores_list = [] |
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for _p_ in self.particles: |
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scores_list.append(_p_.score_current) |
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scores_np = np.array(scores_list) |
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idx_sorted_ind = list(scores_np.argsort()[::-1]) |
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self.p_sorted = [self.particles[i] for i in idx_sorted_ind] |
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def init_pos(self, pos): |
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particle = Particle( |
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self.search_space, |
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inertia=self.inertia, |
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cognitive_weight=self.cognitive_weight, |
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social_weight=self.social_weight, |
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temp_weight=self.temp_weight, |
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rand_rest_p=self.rand_rest_p, |
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) |
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self.particles.append(particle) |
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particle.init_pos(pos) |
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self.p_current = particle |
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self.p_current.velo = np.zeros(len(self.max_positions)) |
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def iterate(self): |
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n_iter = self._iterations(self.particles) |
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self.p_current = self.particles[n_iter % len(self.particles)] |
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self._sort_best() |
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self.p_current.global_pos_best = self.p_sorted[0].pos_best |
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pos = self.p_current.iterate() |
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return pos |
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def evaluate(self, score_new): |
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self.p_current.evaluate(score_new) |
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