source: framspy/evolalg/statistics/halloffame_custom.py @ 1113

Last change on this file since 1113 was 1113, checked in by Maciej Komosinski, 19 months ago

Added a framework for evolutionary algorithms cooperating with FramsticksLib?.py

File size: 2.7 KB
Line 
1from deap.tools import HallOfFame
2import operator
3from copy import deepcopy
4from bisect import bisect_right
5
6class HallOfFameCustom(HallOfFame):
7    def __init__(self,  maxsize, similar=operator.eq, fitness_field="fitness"):
8        super(HallOfFameCustom, self).__init__(maxsize, similar)
9        print("HOF_size =",self.maxsize)
10        self._fitness_field = fitness_field
11
12    def extract_fitness(self, ind):
13        return getattr(ind, self._fitness_field)
14
15    def update(self, population):
16        """Update the hall of fame with the *population* by replacing the
17        worst individuals in it by the best individuals present in
18        *population* (if they are better). The size of the hall of fame is
19        kept constant.
20       
21        :param population: A list of individual with a fitness attribute to
22                           update the hall of fame with.
23        """ 
24        for ind in population:
25            if len(self) == 0 and self.maxsize != 0:
26                # Working on an empty hall of fame is problematic for the
27                # "for else"
28                for hofer in self:
29                    if self.similar(ind, hofer):
30                        break
31                else:
32                    self.insert(population[0])
33               
34                continue
35            if self.extract_fitness(ind) >= self.extract_fitness(self[-1]) or len(self) < self.maxsize:
36                for hofer in self:
37                    # Loop through the hall of fame to check for any
38                    # similar individual
39                    if self.similar(ind, hofer):
40                        break
41                else:
42                    # The individual is unique and strictly better than
43                    # the worst
44                    if len(self) >= self.maxsize:
45                        self.remove(-1)
46                    self.insert(ind)
47
48    def insert(self, item):
49        """Insert a new individual in the hall of fame using the
50        :func:`~bisect.bisect_right` function. The inserted individual is
51        inserted on the right side of an equal individual. Inserting a new
52        individual in the hall of fame also preserve the hall of fame's order.
53        This method **does not** check for the size of the hall of fame, in a
54        way that inserting a new individual in a full hall of fame will not
55        remove the worst individual to maintain a constant size.
56
57        :param item: The individual with a fitness attribute to insert in the
58                     hall of fame.
59        """
60        item = deepcopy(item)
61        i = bisect_right(self.keys, self.extract_fitness(item))
62        self.items.insert(len(self) - i, item)
63        self.keys.insert(i, self.extract_fitness(item))
64
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