写一段代码,运用蚁群算法实现障碍物的最优路线问题,给定条件是:在100x100的网格区域内,设置了一些不同尺寸的障碍物,得出这个人在从(0,0)点出发到(100,100)的最短距离,路径不能穿过障碍物,只能绕开它。
时间: 2023-12-04 22:03:29 浏览: 83
蚁群算法_群智能算法;蚁群算法;背包问题_
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以下是一个简单的 Python 实现,使用了蚁群算法来解决障碍物最优路线问题:
```python
import random
import math
class Ant:
def __init__(self, x, y):
self.x = x
self.y = y
self.distance = 0.0
def move(self, dx, dy):
self.x += dx
self.y += dy
def distance_to(self, x, y):
return math.sqrt((self.x - x) ** 2 + (self.y - y) ** 2)
class Obstacle:
def __init__(self, x, y, size):
self.x = x
self.y = y
self.size = size
def contains(self, x, y):
return (x >= self.x and x < self.x + self.size and
y >= self.y and y < self.y + self.size)
class Grid:
def __init__(self, width, height):
self.width = width
self.height = height
self.obstacles = []
self.ants = []
def add_obstacle(self, obstacle):
self.obstacles.append(obstacle)
def add_ant(self, ant):
self.ants.append(ant)
def remove_ant(self, ant):
self.ants.remove(ant)
def is_obstacle(self, x, y):
for obstacle in self.obstacles:
if obstacle.contains(x, y):
return True
return False
def is_valid_location(self, x, y):
return x >= 0 and x < self.width and y >= 0 and y < self.height and not self.is_obstacle(x, y)
def get_distance(self, ant, x, y):
dx = x - ant.x
dy = y - ant.y
return ant.distance_to(x, y) + math.sqrt(dx ** 2 + dy ** 2)
def get_neighbors(self, ant):
neighbors = []
for dx in [-1, 0, 1]:
for dy in [-1, 0, 1]:
if dx == 0 and dy == 0:
continue
x = ant.x + dx
y = ant.y + dy
if self.is_valid_location(x, y):
neighbors.append((x, y))
return neighbors
def get_pheromone(self, ant, x, y):
return 1.0 / self.get_distance(ant, x, y)
def update_ant(self, ant):
neighbors = self.get_neighbors(ant)
if not neighbors:
return
total_pheromone = 0.0
for neighbor in neighbors:
total_pheromone += self.get_pheromone(ant, neighbor[0], neighbor[1])
probabilities = []
for neighbor in neighbors:
pheromone = self.get_pheromone(ant, neighbor[0], neighbor[1])
probability = pheromone / total_pheromone
probabilities.append((probability, neighbor))
probabilities.sort(reverse=True)
probability_sum = 0.0
r = random.random()
for probability, neighbor in probabilities:
probability_sum += probability
if probability_sum >= r:
ant.move(neighbor[0] - ant.x, neighbor[1] - ant.y)
ant.distance += self.get_distance(ant, neighbor[0], neighbor[1])
if ant.x == self.width - 1 and ant.y == self.height - 1:
self.remove_ant(ant)
break
def update_pheromones(self, evaporation_rate, deposit_rate):
for obstacle in self.obstacles:
for x in range(obstacle.x, obstacle.x + obstacle.size):
for y in range(obstacle.y, obstacle.y + obstacle.size):
if not self.is_valid_location(x, y):
continue
pheromone = 0.0
for ant in self.ants:
pheromone += self.get_pheromone(ant, x, y)
pheromone *= (1.0 - evaporation_rate)
pheromone += deposit_rate
if pheromone < 0.0:
pheromone = 0.0
elif pheromone > 1.0:
pheromone = 1.0
self.grid[x][y] = pheromone
def run(self, num_ants, evaporation_rate, deposit_rate):
for i in range(num_ants):
ant = Ant(0, 0)
self.add_ant(ant)
iterations = 0
while self.ants:
for ant in self.ants:
self.update_ant(ant)
self.update_pheromones(evaporation_rate, deposit_rate)
iterations += 1
return iterations
```
使用该算法可以得出从 (0, 0) 到 (100, 100) 的最短路径,代码如下:
```python
grid = Grid(100, 100)
grid.add_obstacle(Obstacle(20, 20, 30))
grid.add_obstacle(Obstacle(40, 40, 20))
grid.add_obstacle(Obstacle(70, 60, 10))
iterations = grid.run(100, 0.1, 1.0)
print("Iterations:", iterations)
```
其中,`grid` 表示网格,`Grid` 类封装了整个算法,`Obstacle` 类表示障碍物,`Ant` 类表示蚂蚁。`run` 方法运行整个算法,`num_ants` 表示蚂蚁数量,`evaporation_rate` 表示挥发率,`deposit_rate` 表示沉积率。在这个例子中,我们设置了三个障碍物,调用 `run` 方法得出了最短路径所需的迭代次数,即 `iterations`。
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