def reverse_sequence_Mutation(mutationRate: float, tour: Tour) -> Tour:
# Mutated Child
mutated = Tour()
# Getting Sub-tour
startpos = randrange(0, tour.getSize())
endpos = randrange(0, tour.getSize())
if(startpos > endpos):
startpos, endpos = endpos, startpos
mutated.tour = tour.tour[0:startpos] + \
list(reversed(tour.tour[startpos:endpos])) + tour.tour[endpos:]
return mutated
def mainloop(self):
self.sortPopulation()
for i in range(self.iteration_limit):
blackHole = self.tours[0]
# Moving Stars toward the Black Hole
for j in range(1, self.population_size):
newStar = self.moveCloser(blackHole, self.tours[j])
self.setTour(j, newStar)
# Checking for Event Horizon
blackHole_value = 1 / self.tours[0].getDistance()
sumValues = [
1 / self.tours[j].getDistance()
for j in range(1, self.population_size)
]
# Deaths of stars
radius = blackHole_value / sum(sumValues)
for j in range(1, self.population_size):
if (abs(self.tours[j].getDistance() - blackHole_value) <
radius):
self.setTour(j, Tour())
self.sortPopulation()
if i % 10 == 0:
print(
f"Generation: {i} Best Fitness: {self.tours[0].getDistance()}"
)
return self.tours, i
def __init__(self, population_size, iteration_limit):
# Store the stars
self.population_size = population_size
self.tours = [Tour() for _ in range(population_size)]
# Max Iterations
self.iteration_limit = iteration_limit
def __init__(self, size: int, initialize: bool) -> None:
# Holds Population of Tours
self.tours: List[Tour] = []
# Initializing Population
if initialize:
self.tours = [Tour() for _ in range(size)]
else:
self.tours = [None for _ in range(size)]
def swap_Mutation(mutationRate: float, tour: Tour) -> Tour:
for i, city in enumerate(tour.tour):
if random() <= mutationRate:
# Getting second random city
randomId = randrange(0, tour.getSize())
other_city = tour.getCity(randomId)
# Swapping the Route
tour.setCity(i, other_city)
tour.setCity(randomId, city)
return tour
def moveCloser(self, blackHole, star):
min_possible = star.getDistance()
min_tour = star
for i in range(7):
# New Child
newStar = Tour()
# Getting Sub-tour
startpos = randrange(0, blackHole.getSize())
endpos = randrange(0, blackHole.getSize())
if (startpos > endpos):
startpos, endpos = endpos, startpos
for i in range(newStar.getSize()):
if i > startpos and i < endpos:
newStar.setCity(i, blackHole.getCity(i))
else:
newStar.setCity(i, None)
for i in range(newStar.getSize()):
if not newStar.containsCity(star.getCity(i)):
for j in range(0, newStar.getSize()):
if newStar.getCity(j) == None:
newStar.setCity(j, star.getCity(i))
break
if (newStar.getDistance(True) < min_possible):
return newStar
return min_tour
def ordered_crossover(parent_a: Tour, parent_b: Tour) -> Tour:
# New Child
offspring = Tour()
# Getting Sub-tour
startpos = randrange(0, parent_a.getSize())
endpos = randrange(0, parent_a.getSize())
if(startpos > endpos):
startpos, endpos = endpos, startpos
for i in range(offspring.getSize()):
if i > startpos and i < endpos:
offspring.setCity(i, parent_a.getCity(i))
else:
offspring.setCity(i, None)
for i in range(offspring.getSize()):
if not offspring.containsCity(parent_b.getCity(i)):
for j in range(0, offspring.getSize()):
if offspring.getCity(j) == None:
offspring.setCity(j, parent_b.getCity(i))
break
return offspring