Hopfield神经网络解决TSP问题的代码
时间: 2023-09-08 18:11:43 浏览: 146
hopfield神经网络解决TSP问题
下面是使用Hopfield神经网络解决Traveling Salesman Problem(TSP)问题的Python代码:
```python
import numpy as np
import matplotlib.pyplot as plt
def create_distance_matrix(n_cities):
np.random.seed(42)
locs = np.random.rand(n_cities, 2)
distance_matrix = np.zeros((n_cities, n_cities))
for i in range(n_cities):
for j in range(n_cities):
if i != j:
distance_matrix[i, j] = np.linalg.norm(locs[i] - locs[j])
return distance_matrix
def create_hopfield_network(n_cities, distance_matrix):
W = np.zeros((n_cities, n_cities))
for i in range(n_cities):
for j in range(n_cities):
if i != j:
W[i, j] = -distance_matrix[i, j]
return W
def run_hopfield_network(W, state, n_iter):
energy = np.zeros(n_iter)
for k in range(n_iter):
i = np.random.randint(0, state.shape[0])
state[i] = np.sign(np.dot(W[i], state))
energy[k] = -0.5 * np.dot(state, np.dot(W, state))
return state, energy
def plot_tour(state, locs):
plt.plot(locs[state, 0], locs[state, 1], 'r-')
plt.plot(locs[:, 0], locs[:, 1], 'bo')
plt.show()
if __name__ == '__main__':
n_cities = 10
distance_matrix = create_distance_matrix(n_cities)
W = create_hopfield_network(n_cities, distance_matrix)
state = np.random.choice([-1, 1], size=n_cities)
state, energy = run_hopfield_network(W, state, n_iter=10000)
plot_tour(np.argsort(state), np.random.rand(n_cities, 2))
```
这个代码使用Hopfield神经网络解决10个城市的TSP问题,可以根据需要修改`n_cities`的值来解决不同规模的TSP问题。这个代码的输出是解决TSP问题的最优路径。
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