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Author SHA1 Message Date
c6118e2d86 Add summary 2021-06-22 15:16:46 +02:00
03afe1a00f Execute each algorithm once 2021-06-22 01:47:11 +02:00
1aafc9bdda Fix element modification in dataframe list 2021-06-22 01:10:05 +02:00
fb5e9dc703 Remove redundant code 2021-06-22 00:21:14 +02:00
112f40d00f Replace the population after the local search 2021-06-21 21:41:00 +02:00
32eac42e7b Take into account local search iterations 2021-06-21 19:51:42 +02:00
f61cb7002e Implement memetic algorithm 2021-06-21 18:22:38 +02:00
9aeff47bb1 Fix parameters typos 2021-06-21 17:57:48 +02:00
764d235b4d Rename populate dataframes to populate dataframe 2021-06-21 17:56:52 +02:00
7cbb25c546 Add local search module 2021-06-21 17:54:37 +02:00
20aa6b2d1e Refactor execution script 2021-06-21 17:54:26 +02:00
4e640ffc2d Add memetic algorithm prototype 2021-06-21 07:39:51 +02:00
ab4748d28e Change fitness evaluation 2021-06-21 07:39:39 +02:00
c2cc3c716d Limit number of iterations to 100 2021-06-21 03:50:14 +02:00
e20e16d476 Clean up genetic algorithm 2021-06-21 03:48:50 +02:00
924e4c9638 Change CLI using argparse 2021-06-21 03:46:35 +02:00
f4dd4700c7 Add crossover probability 2021-06-21 02:25:54 +02:00
35ca73ba74 Refactor parent grouping making it more resilient 2021-06-21 02:08:27 +02:00
48737fd6f0 Refactor best point selection 2021-06-21 00:47:48 +02:00
efd511e070 Fix populate offspring 2021-06-20 19:48:04 +02:00
5f89731f77 Fix uniform crossover function 2021-06-20 18:04:23 +02:00
046b1a043a Implement uniform generational genetic algorithm 2021-06-20 05:24:56 +02:00
8 changed files with 425 additions and 199 deletions

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#+TITLE: Práctica 2
#+SUBTITLE: Metaheurísticas
#+AUTHOR: Amin Kasrou Aouam
#+DATE: 2021-06-22
#+PANDOC_OPTIONS: template:~/.pandoc/templates/eisvogel.latex
#+PANDOC_OPTIONS: listings:t
#+PANDOC_OPTIONS: toc:t
#+PANDOC_METADATA: lang=es
#+PANDOC_METADATA: titlepage:t
#+PANDOC_METADATA: listings-no-page-break:t
#+PANDOC_METADATA: toc-own-page:t
#+PANDOC_METADATA: table-use-row-colors:t
#+PANDOC_METADATA: colorlinks:t
#+PANDOC_METADATA: logo:/home/coolneng/Photos/Logos/UGR.png
#+LaTeX_HEADER: \usepackage[ruled, lined, linesnumbered, commentsnumbered, longend]{algorithm2e}
* Práctica 2
** Introducción
En esta práctica, usaremos distintos algoritmos de búsqueda, basados en poblaciones, para resolver el problema de la máxima diversidad (MDP). Implementaremos:
- Algoritmo genético
- Algoritmo memético
** Algoritmos
*** Genético
Los algoritmos genéticos se inspiran en la evolución natural y la genética. Generan un conjunto de soluciones inicial (i.e. población), seleccionan un subconjunto de individuos sobre los cuales se opera, hacen operaciones de recombinación y mutación, y finalmente reemplazan la población anterior por una nueva.
El procedimiento general del algoritmo queda ilustrado a continuación:
\begin{algorithm}
\KwIn{A list $[a_i]$, $i=1, 2, \cdots, n$, that contains the population of individuals}
\KwOut{Processed list}
$P(t) \leftarrow initializePopulation()$
$P(t) \leftarrow evaluatePopulation()$
\While{$\neg stop condition $}{
$t = t + 1$
$parents \leftarrow selectParents(P(t-1))$
$offspring \leftarrow recombine(parents)$
$offspring \leftarrow mutate(offspring)$
$P(t) \leftarrow replacePopulation(P(t-1), offspring)$
$P(t) \leftarrow evaluatePopulation()$
}
\KwRet{$P(t)$}
\end{algorithm}
Procedemos a la implementación de 4 variantes distintas, según 2 criterios:
**** Criterio de reemplazamiento
- *Generacional*: la nueva población reemplaza totalmente a la población anterior
- *Estacionario*: los dos mejores hijos reemplazan los dos peores individuos en la población anterior
**** Operador de cruce
- *Uniforme*: mantiene las posiciones comunes de ambos padres, las demás se eligen de forma aleatoria de cada padre (requiere reparador)
- *Posición*: mantiene las posiciones comunes de ambos padres, elige el resto de elementos de cada padre y los baraja. Genera 2 hijos.
*** Memético
Los algoritmos meméticos surgen de la hibridación de un algoritmo genético, con un algoritmo de búsqueda local. El resultado es un algoritmo que posee un buen equilibrio entre exploración y explotación.
El procedimiento general del algoritmo queda ilustrado a continuación:
\begin{algorithm}
\KwIn{A list $[a_i]$, $i=1, 2, \cdots, n$, that contains the population of individuals}
\KwOut{Processed list}
$P(t) \leftarrow initializePopulation()$
$P(t) \leftarrow evaluatePopulation()$
\While{$\neg stop condition $}{
\If{$certain iteration$}{
$P(t) <- localSearch(P(t-1))$
}
$t = t + 1$
$parents \leftarrow selectParents(P(t-1))$
$offspring \leftarrow recombine(parents)$
$offspring \leftarrow mutate(offspring)$
$P(t) \leftarrow replacePopulation(P(t-1), offspring)$
$P(t) \leftarrow evaluatePopulation()$
}
\KwRet{$P(t)$}
\end{algorithm}
Procedemos a la implementación de 3 variantes distintas:
- Búsqueda local sobre todos los cromosomas
- Búsqueda local sobre un subconjunto aleatorio de cromosomas
- Búsqueda local sobre un el subconjunto de los mejores cromosomas
** Implementación
La práctica ha sido implementada en /Python/, usando las siguientes bibliotecas:
- NumPy
- Pandas
*** Instalación
Para ejecutar el programa es preciso instalar Python, junto con las bibliotecas *Pandas* y *NumPy*.
Se proporciona el archivo shell.nix para facilitar la instalación de las dependencias, con el gestor de paquetes [[https://nixos.org/][Nix]]. Tras instalar la herramienta Nix, únicamente habría que ejecutar el siguiente comando en la raíz del proyecto:
#+begin_src shell
nix-shell
#+end_src
** Ejecución
La ejecución del programa se realiza mediante el siguiente comando:
#+begin_src shell
python src/main.py <dataset> <algoritmo> <parámetros>
#+end_src
Los parámetros posibles son:
| dataset | algoritmo | parámetros |
| Cualquier archivo de la carpeta data | genetic | uniform/position generation/stationary |
| | memetic | all/random/best |
También se proporciona un script que ejecuta 1 iteración de cada algoritmo, sobre cada uno de los /datasets/, y guarda los resultados en una hoja de cálculo. Se puede ejecutar mediante el siguiente comando:
#+begin_src shell
python src/execution.py
#+end_src
*Nota*: se precisa instalar la biblioteca [[https://xlsxwriter.readthedocs.io/][XlsxWriter]] para la exportación de los resultados a un archivo Excel.
* Análisis de los resultados
Desafortunadamente, debido a un tiempo de ejecución excesivamente alto (incluso tras ajustar los metaparámetros) no podemos proporcionar resultados de la ejecución de los algoritmos.

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@@ -14,70 +14,67 @@ def file_list(path):
def create_dataframes(): def create_dataframes():
greedy = DataFrame() return [DataFrame() for _ in range(7)]
local = DataFrame()
return greedy, local
def process_output(results): def process_output(results):
distances = [] distances = []
time = [] time = []
for element in results: for line in results:
for line in element: if line.startswith(bytes("Total distance:", encoding="utf-8")):
if line.startswith(bytes("Total distance:", encoding="utf-8")): line_elements = line.split(sep=bytes(":", encoding="utf-8"))
line_elements = line.split(sep=bytes(":", encoding="utf-8")) distances.append(float(line_elements[1]))
distances.append(float(line_elements[1])) if line.startswith(bytes("Execution time:", encoding="utf-8")):
if line.startswith(bytes("Execution time:", encoding="utf-8")): line_elements = line.split(sep=bytes(":", encoding="utf-8"))
line_elements = line.split(sep=bytes(":", encoding="utf-8")) time.append(float(line_elements[1]))
time.append(float(line_elements[1]))
return distances, time return distances, time
def populate_dataframes(greedy, local, greedy_list, local_list, dataset): def populate_dataframe(df, output_cmd, dataset):
greedy_distances, greedy_time = process_output(greedy_list) distances, time = process_output(output_cmd)
local_distances, local_time = process_output(local_list) data_dict = {
greedy_dict = {
"dataset": dataset.removeprefix("data/"), "dataset": dataset.removeprefix("data/"),
"media distancia": mean(greedy_distances), "media distancia": mean(distances),
"desviacion distancia": std(greedy_distances), "desviacion distancia": std(distances),
"media tiempo": mean(greedy_time), "media tiempo": mean(time),
"desviacion tiempo": std(greedy_time), "desviacion tiempo": std(time),
} }
local_dict = { df = df.append(data_dict, ignore_index=True)
"dataset": dataset.removeprefix("data/"), return df
"media distancia": mean(local_distances),
"desviacion distancia": std(local_distances),
"media tiempo": mean(local_time),
"desviacion tiempo": std(local_time),
}
greedy = greedy.append(greedy_dict, ignore_index=True)
local = local.append(local_dict, ignore_index=True)
return greedy, local
def script_execution(filenames, greedy, local, iterations=3): def script_execution(filenames, df_list):
script = "src/main.py" script = "src/main.py"
parameters = [
["genetic", "uniform", "generational"],
["genetic", "position", "generational"],
["genetic", "uniform", "stationary"],
["genetic", "position", "stationary"],
["memetic", "all"],
["memetic", "random"],
["memetic", "best"],
]
for dataset in filenames: for dataset in filenames:
print(f"Running on dataset {dataset}") print(f"Running on dataset {dataset}")
greedy_list = [] for index, params in zip(range(4), parameters):
local_list = [] print(f"Running {params} algorithm")
for _ in range(iterations): output_cmd = run(
greedy_cmd = run( [executable, script, dataset, *params], capture_output=True
[executable, script, dataset, "greedy"], capture_output=True
).stdout.splitlines() ).stdout.splitlines()
local_cmd = run( df_list[index] = populate_dataframe(df_list[index], output_cmd, dataset)
[executable, script, dataset, "local"], capture_output=True return df_list
).stdout.splitlines()
greedy_list.append(greedy_cmd)
local_list.append(local_cmd)
greedy, local = populate_dataframes(
greedy, local, greedy_list, local_list, dataset
)
return greedy, local
def export_results(greedy, local): def export_results(df_list):
dataframes = {"Greedy": greedy, "Local search": local} dataframes = {
"Generational uniform genetic": df_list[0],
"Generational position genetic": df_list[1],
"Stationary uniform genetic": df_list[2],
"Stationary position genetic": df_list[3],
"All genes memetic": df_list[4],
"Random genes memetic": df_list[5],
"Best genes memetic": df_list[6],
}
writer = ExcelWriter(path="docs/algorithm-results.xlsx", engine="xlsxwriter") writer = ExcelWriter(path="docs/algorithm-results.xlsx", engine="xlsxwriter")
for name, df in dataframes.items(): for name, df in dataframes.items():
df.to_excel(writer, sheet_name=name, index=False) df.to_excel(writer, sheet_name=name, index=False)
@@ -91,9 +88,9 @@ def export_results(greedy, local):
def main(): def main():
datasets = file_list(path="data/*.txt") datasets = file_list(path="data/*.txt")
greedy, local = create_dataframes() df_list = create_dataframes()
populated_greedy, populated_local = script_execution(datasets, greedy, local) populated_df_list = script_execution(datasets, df_list)
export_results(populated_greedy, populated_local) export_results(populated_df_list)
if __name__ == "__main__": if __name__ == "__main__":

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@@ -1,12 +1,11 @@
from numpy import sum, append, arange, delete, intersect1d from numpy import intersect1d, array_equal
from numpy.random import randint, choice, shuffle from numpy.random import randint, choice, shuffle
from pandas import DataFrame from pandas import DataFrame
from math import ceil from math import ceil
from functools import partial from functools import partial
from multiprocessing import Pool from multiprocessing import Pool
from copy import deepcopy from copy import deepcopy
from itertools import combinations
from preprocessing import parse_file
def get_row_distance(source, destination, data): def get_row_distance(source, destination, data):
@@ -37,33 +36,36 @@ def generate_individual(n, m, data):
def evaluate_individual(individual, data): def evaluate_individual(individual, data):
fitness = [] fitness = 0
genotype = individual.point.values comb = combinations(individual.index, r=2)
distances = data.query(f"source in @genotype and destination in @genotype") for index in list(comb):
for item in genotype[:-1]: elements = individual.loc[index, :]
element_df = distances.query(f"source == {item} or destination == {item}") fitness += get_row_distance(
max_distance = element_df["distance"].astype(float).max() source=elements["point"].head(n=1).values[0],
fitness = append(arr=fitness, values=max_distance) destination=elements["point"].tail(n=1).values[0],
distances = distances.query(f"source != {item} and destination != {item}") data=data,
individual["fitness"] = sum(fitness) )
individual["fitness"] = fitness
return individual return individual
def select_distinct_genes(matching_genes, parents, m): def select_distinct_genes(matching_genes, parents, m):
first_parent = parents[0].query("point not in @matching_genes") first_parent = parents[0].query("point not in @matching_genes")
second_parent = parents[1].query("point not in @matching_genes") second_parent = parents[1].query("point not in @matching_genes")
cutoff = randint(m - len(matching_genes)) cutoff = randint(m - len(matching_genes) + 1)
first_parent_genes = first_parent.point.values[cutoff:] first_parent_genes = first_parent.point.values[cutoff:]
second_parent_genes = second_parent.point.values[:cutoff] second_parent_genes = second_parent.point.values[:cutoff]
return first_parent_genes, second_parent_genes return first_parent_genes, second_parent_genes
def select_random_genes(matching_genes, parents, m): def select_shuffled_genes(matching_genes, parents):
random_parent = parents[randint(len(parents))] first_parent = parents[0].query("point not in @matching_genes")
distinct_indexes = delete(arange(m), matching_genes) second_parent = parents[1].query("point not in @matching_genes")
genes = random_parent.point.iloc[distinct_indexes].values first_genes = first_parent.point.values
shuffle(genes) second_genes = second_parent.point.values
return genes shuffle(first_genes)
shuffle(second_genes)
return first_genes, second_genes
def select_random_parent(parents): def select_random_parent(parents):
@@ -75,20 +77,23 @@ def select_random_parent(parents):
return random_parent return random_parent
def get_best_point(parents, offspring):
while True:
random_parent = deepcopy(select_random_parent(parents))
best_index = random_parent["distance"].idxmax()
best_point = random_parent["point"].iloc[best_index]
random_parent.drop(index=best_index, inplace=True)
if best_point not in offspring.point.values:
return best_point
def repair_offspring(offspring, parents, m): def repair_offspring(offspring, parents, m):
while len(offspring) != m: while len(offspring) != m:
if len(offspring) > m: if len(offspring) > m:
best_index = offspring["distance"].idxmax() best_index = offspring["distance"].idxmax()
offspring.drop(index=best_index, inplace=True) offspring.drop(index=best_index, inplace=True)
elif len(offspring) < m: elif len(offspring) < m:
# NOTE Refactor into its own function best_point = get_best_point(parents, offspring)
while True:
random_parent = select_random_parent(parents)
best_index = random_parent["distance"].idxmax()
best_point = random_parent["point"].loc[best_index]
random_parent.drop(index=best_index, inplace=True)
if best_point not in offspring.point.values:
break
offspring = offspring.append( offspring = offspring.append(
{"point": best_point, "distance": 0, "fitness": 0}, ignore_index=True {"point": best_point, "distance": 0, "fitness": 0}, ignore_index=True
) )
@@ -109,7 +114,6 @@ def populate_offspring(values):
offspring = offspring.append(aux) offspring = offspring.append(aux)
offspring["distance"] = 0 offspring["distance"] = 0
offspring["fitness"] = 0 offspring["fitness"] = 0
offspring = offspring[1:]
return offspring return offspring
@@ -121,21 +125,43 @@ def uniform_crossover(parents, m):
return viable_offspring return viable_offspring
def position_crossover(parents, m): def position_crossover(parents):
matching_genes = get_matching_genes(parents) matching_genes = get_matching_genes(parents)
shuffled_genes = select_random_genes(matching_genes, parents, m) first_genes, second_genes = select_shuffled_genes(matching_genes, parents)
first_offspring = populate_offspring(values=[matching_genes, shuffled_genes]) first_offspring = populate_offspring(values=[matching_genes, first_genes])
second_offspring = populate_offspring(values=[matching_genes, shuffled_genes]) second_offspring = populate_offspring(values=[matching_genes, second_genes])
return [first_offspring, second_offspring] return first_offspring, second_offspring
def crossover(mode, parents, m): def group_parents(parents):
split_parents = zip(*[iter(parents)] * 2) parent_pairs = []
for i in range(0, len(parents), 2):
first = parents[i]
second = parents[i + 1]
if array_equal(first.point.values, second.point.values):
random_index = randint(i + 1)
second, parents[random_index] = parents[random_index], second
parent_pairs.append([first, second])
return parent_pairs
def crossover(mode, parents, m, probability=0.7):
parent_groups = group_parents(parents)
offspring = []
if mode == "uniform": if mode == "uniform":
crossover_func = partial(uniform_crossover, m=m) expected_crossovers = int(len(parents) * probability)
cutoff = expected_crossovers // 2
for element in parent_groups[:cutoff]:
offspring.append(uniform_crossover(element, m))
offspring.append(uniform_crossover(element, m))
for element in parent_groups[cutoff:]:
offspring.append(element[0])
offspring.append(element[1])
else: else:
crossover_func = partial(position_crossover, m=m) for element in parent_groups:
offspring = [*map(crossover_func, split_parents)] first_offspring, second_offspring = position_crossover(element)
offspring.append(first_offspring)
offspring.append(second_offspring)
return offspring return offspring
@@ -151,7 +177,7 @@ def select_new_gene(individual, n):
return new_gene return new_gene
def mutate(offspring, data, probability=0.001): def mutate(offspring, n, data, probability=0.001):
expected_mutations = len(offspring) * n * probability expected_mutations = len(offspring) * n * probability
individuals = [] individuals = []
genes = [] genes = []
@@ -185,7 +211,7 @@ def tournament_selection(population):
def check_element_population(element, population): def check_element_population(element, population):
for item in population: for item in population:
if all(element.point.values) == all(item.point.values): if array_equal(element.point.values, item.point.values):
return True return True
return False return False
@@ -201,27 +227,36 @@ def generational_replacement(prev_population, current_population):
def get_best_elements(population): def get_best_elements(population):
first_element = max(population, key=lambda x: x.fitness.values[0]) select_population = deepcopy(population)
first_index = get_individual_index(first_element, population) first_element = max(select_population, key=lambda x: x.fitness.values[0])
population.pop(first_index) first_index = get_individual_index(first_element, select_population)
second_element = max(population, key=lambda x: x.fitness.values[0]) select_population.pop(first_index)
second_index = get_individual_index(second_element, population) second_element = max(select_population, key=lambda x: x.fitness.values[0])
second_index = get_individual_index(second_element, select_population)
return first_index, second_index return first_index, second_index
def get_worst_elements(population): def get_worst_elements(population):
first_index = population.index(min(population, key=lambda x: all(x.fitness))) select_population = deepcopy(population)
population.pop(first_index) first_element = min(select_population, key=lambda x: x.fitness.values[0])
second_index = population.index(min(population, key=lambda x: all(x.fitness))) first_index = get_individual_index(first_element, select_population)
select_population.pop(first_index)
second_element = min(select_population, key=lambda x: x.fitness.values[0])
second_index = get_individual_index(second_element, select_population)
return first_index, second_index return first_index, second_index
def stationary_replacement(prev_population, current_population): def stationary_replacement(prev_population, current_population):
new_population = prev_population new_population = prev_population
worst_indexes = get_worst_elements(prev_population) first_worst, second_worst = get_worst_elements(prev_population)
best_indexes = get_best_elements(current_population) first_best, second_best = get_best_elements(current_population)
worst_indexes = [first_worst, second_worst]
best_indexes = [first_best, second_best]
for worst, best in zip(worst_indexes, best_indexes): for worst, best in zip(worst_indexes, best_indexes):
if current_population[best].fitness > prev_population[worst].fitness: if (
current_population[best].fitness.values[0]
> prev_population[worst].fitness.values[0]
):
new_population[worst] = current_population[best] new_population[worst] = current_population[best]
return new_population return new_population
@@ -261,19 +296,8 @@ def genetic_algorithm(n, m, data, select_mode, crossover_mode, max_iterations=10
for _ in range(max_iterations): for _ in range(max_iterations):
parents = select_parents(population, n, select_mode) parents = select_parents(population, n, select_mode)
offspring = crossover(crossover_mode, parents, m) offspring = crossover(crossover_mode, parents, m)
offspring = mutate(offspring, data) offspring = mutate(offspring, n, data)
population = replace_population(population, offspring, select_mode) population = replace_population(population, offspring, select_mode)
population = evaluate_population(population, data) population = evaluate_population(population, data)
best_index, _ = get_best_elements(population) best_index, _ = get_best_elements(population)
return population[best_index] return population[best_index]
n, m, data = parse_file("data/GKD-c_11_n500_m50.txt")
genetic_algorithm(
n=10,
m=4,
data=data,
select_mode="generational",
crossover_mode="uniform",
max_iterations=1,
)

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@@ -0,0 +1,64 @@
from numpy.random import choice, seed, randint
from pandas import DataFrame
def get_row_distance(source, destination, data):
row = data.query(
"""(source == @source and destination == @destination) or \
(source == @destination and destination == @source)"""
)
return row["distance"].values[0]
def compute_distance(element, solution, data):
accumulator = 0
distinct_elements = solution.query(f"point != {element}")
for _, item in distinct_elements.iterrows():
accumulator += get_row_distance(
source=element,
destination=item.point,
data=data,
)
return accumulator
def element_in_dataframe(solution, element):
duplicates = solution.query(f"point == {element}")
return not duplicates.empty
def replace_worst_element(previous, n, data):
solution = previous.copy()
worst_index = solution["distance"].astype(float).idxmin()
random_element = randint(n)
while element_in_dataframe(solution=solution, element=random_element):
random_element = randint(n)
solution["point"].loc[worst_index] = random_element
solution["distance"].loc[worst_index] = compute_distance(
element=solution["point"].loc[worst_index], solution=solution, data=data
)
return solution
def get_random_solution(previous, n, data):
solution = replace_worst_element(previous, n, data)
while solution["distance"].sum() <= previous["distance"].sum():
solution = replace_worst_element(previous=solution, n=n, data=data)
return solution
def explore_neighbourhood(element, n, data, max_iterations=100000):
neighbourhood = []
neighbourhood.append(element)
for _ in range(max_iterations):
previous_solution = neighbourhood[-1]
neighbour = get_random_solution(previous=previous_solution, n=n, data=data)
neighbourhood.append(neighbour)
return neighbour
def local_search(first_solution, n, data):
best_solution = explore_neighbourhood(
element=first_solution, n=n, data=data, max_iterations=5
)
return best_solution

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@@ -1,68 +1,57 @@
from preprocessing import parse_file from preprocessing import parse_file
from genetic_algorithm import genetic_algorithm from genetic_algorithm import genetic_algorithm
from memetic_algorithm import memetic_algorithm from memetic_algorithm import memetic_algorithm
from sys import argv
from time import time from time import time
from itertools import combinations from argparse import ArgumentParser
def execute_algorithm(choice, n, m, data): def execute_algorithm(args, n, m, data):
if choice == "genetic": if args.algorithm == "genetic":
return genetic_algorithm(n, m, data) return genetic_algorithm(
elif choice == "memetic": n,
return memetic_algorithm(m, data) m,
else: data,
print("The valid algorithm choices are 'genetic' and 'memetic'") select_mode=args.selection,
exit(1) crossover_mode=args.crossover,
max_iterations=100,
def get_row_distance(source, destination, data):
row = data.query(
"""(source == @source and destination == @destination) or \
(source == @destination and destination == @source)"""
)
return row["distance"].values[0]
def get_fitness(solutions, data):
counter = 0
comb = combinations(solutions.index, r=2)
for index in list(comb):
elements = solutions.loc[index, :]
counter += get_row_distance(
source=elements["point"].head(n=1).values[0],
destination=elements["point"].tail(n=1).values[0],
data=data,
) )
return counter return memetic_algorithm(
n,
m,
data,
hybridation=args.hybridation,
max_iterations=100,
)
def show_results(solutions, fitness, time_delta): def show_results(solution, time_delta):
duplicates = solutions.duplicated().any() duplicates = solution.duplicated().any()
print(solutions) print(solution)
print(f"Total distance: {fitness}") print(f"Total distance: {solution.fitness.values[0]}")
if not duplicates: if not duplicates:
print("No duplicates found") print("No duplicates found")
print(f"Execution time: {time_delta}") print(f"Execution time: {time_delta}")
def usage(argv): def parse_arguments():
print(f"Usage: python {argv[0]} <file> <algorithm choice>") parser = ArgumentParser()
print("algorithm choices:") parser.add_argument("file", help="dataset of choice")
print("genetic: genetic algorithm") subparsers = parser.add_subparsers(dest="algorithm")
print("memetic: memetic algorithm") parser_genetic = subparsers.add_parser("genetic")
exit(1) parser_memetic = subparsers.add_parser("memetic")
parser_genetic.add_argument("crossover", choices=["uniform", "position"])
parser_genetic.add_argument("selection", choices=["generational", "stationary"])
parser_memetic.add_argument("hybridation", choices=["all", "random", "best"])
return parser.parse_args()
def main(): def main():
if len(argv) != 3: args = parse_arguments()
usage(argv) n, m, data = parse_file(args.file)
n, m, data = parse_file(argv[1])
start_time = time() start_time = time()
solutions = execute_algorithm(choice=argv[2], n=n, m=m, data=data) solutions = execute_algorithm(args, n, m, data)
end_time = time() end_time = time()
fitness = get_fitness(solutions, data) show_results(solutions, time_delta=end_time - start_time)
show_results(solutions, fitness, time_delta=end_time - start_time)
if __name__ == "__main__": if __name__ == "__main__":

View File

@@ -1,50 +1,59 @@
from numpy.random import choice, seed from genetic_algorithm import *
from local_search import local_search
from copy import deepcopy
def get_first_random_solution(m, data): def get_best_indices(n, population):
seed(42) select_population = deepcopy(population)
random_indexes = choice(len(data.index), size=m, replace=False) best_elements = []
return data.loc[random_indexes] for _ in range(n):
best_index, _ = get_best_elements(select_population)
best_elements.append(best_index)
select_population.pop(best_index)
return best_elements
def element_in_dataframe(solution, element): def replace_elements(current_population, new_population, indices):
duplicates = solution.query( for item in indices:
f"(source == {element.source} and destination == {element.destination}) or (source == {element.destination} and destination == {element.source})" current_population[item] = new_population[item]
) return current_population
return not duplicates.empty
def replace_worst_element(previous, data): def run_local_search(n, data, population, mode, probability=0.1):
solution = previous.copy()
worst_index = solution["distance"].astype(float).idxmin()
random_element = data.sample().squeeze()
while element_in_dataframe(solution=solution, element=random_element):
random_element = data.sample().squeeze()
solution.loc[worst_index] = random_element
return solution, worst_index
def get_random_solution(previous, data):
solution, worst_index = replace_worst_element(previous, data)
previous_worst_distance = previous["distance"].loc[worst_index]
while solution.distance.loc[worst_index] <= previous_worst_distance:
solution, _ = replace_worst_element(previous=solution, data=data)
return solution
def explore_neighbourhood(element, data, max_iterations=100000):
neighbourhood = [] neighbourhood = []
neighbourhood.append(element) if mode == "all":
for _ in range(max_iterations): for individual in population:
previous_solution = neighbourhood[-1] neighbourhood.append(local_search(individual, n, data))
neighbour = get_random_solution(previous=previous_solution, data=data) new_population = neighbourhood
neighbourhood.append(neighbour) elif mode == "random":
return neighbour expected_individuals = len(population) * probability
indices = []
for _ in range(expected_individuals):
random_index = randint(len(population))
random_individual = population[random_index]
neighbourhood.append(local_search(random_individual, n, data))
indices.append(random_index)
new_population = replace_elements(population, neighbourhood, indices)
else:
expected_individuals = len(population) * probability
best_indices = get_best_indices(n=expected_individuals, population=population)
for element in best_indices:
neighbourhood.append(local_search(population[element], n, data))
new_population = replace_elements(population, neighbourhood, best_indices)
return new_population
def memetic_algorithm(m, data): def memetic_algorithm(n, m, data, hybridation, max_iterations=100000):
first_solution = get_first_random_solution(m=m, data=data) population = [generate_individual(n, m, data) for _ in range(n)]
best_solution = explore_neighbourhood( population = evaluate_population(population, data)
element=first_solution, data=data, max_iterations=100 for i in range(max_iterations):
) if i % 10 == 0:
return best_solution population = run_local_search(n, data, population, mode=hybridation)
i += 5
parents = select_parents(population, n, mode="stationary")
offspring = crossover(mode="position", parents=parents, m=m)
offspring = mutate(offspring, n, data)
population = replace_population(population, offspring, mode="stationary")
population = evaluate_population(population, data)
best_index, _ = get_best_elements(population)
return population[best_index]