编写pytorch代码,定义FA_CPSO优化算法,在这个算法下面初始化粒子群的参数,通过混沌粒子群算法迭代更新粒子群的参数,在参数达到最优时加入萤火虫随机扰动,进一步优化参数,直到得到最优参数
时间: 2024-04-02 08:35:15 浏览: 72
添加扰动项的萤火虫算法FA,,基于FA的目标函数优化
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好的,我可以为您提供一些代码示例。首先,我们需要定义FA_CPSO优化算法和混沌粒子群算法。以下是基本的FA_CPSO优化算法代码:
```python
import torch
def FA_CPSO(objective_func, lb, ub, dim, NP, iter_max, w, c1, c2):
# 初始化粒子群
X = lb + (ub - lb) * torch.rand(NP, dim)
V = torch.zeros(NP, dim)
P = X.clone()
P_fit = torch.zeros(NP)
G, G_fit = torch.zeros(dim), float('inf')
# 迭代更新
for i in range(iter_max):
for j in range(NP):
# 计算适应度
fit = objective_func(X[j])
if fit < P_fit[j]:
P[j] = X[j].clone()
P_fit[j] = fit
if P_fit[j] < G_fit:
G = P[j].clone()
G_fit = P_fit[j]
# 更新速度和位置
r1, r2 = torch.rand(dim), torch.rand(dim)
V[j] = w * V[j] + c1 * r1 * (P[j] - X[j]) + c2 * r2 * (G - X[j])
X[j] = X[j] + V[j]
X[j] = torch.clamp(X[j], lb, ub)
return G, G_fit
```
接下来,我们可以定义混沌粒子群算法。这里我们使用了Lorenz混沌系统,可以根据需要进行更改。
```python
def chaotic_map(X, a, b, c):
# Lorenz混沌系统的公式
x_dot = a * (X[1] - X[0])
y_dot = X[0] * (b - X[2]) - X[1]
z_dot = X[0] * X[1] - c * X[2]
return torch.tensor([x_dot, y_dot, z_dot])
def CPSO_with_chaos(objective_func, lb, ub, dim, NP, iter_max, w, c1, c2):
# 初始化粒子群
X = lb + (ub - lb) * torch.rand(NP, dim)
V = torch.zeros(NP, dim)
P = X.clone()
P_fit = torch.zeros(NP)
G, G_fit = torch.zeros(dim), float('inf')
# 迭代更新
for i in range(iter_max):
# 计算混沌映射
a, b, c = 10.0, 28.0, 8.0 / 3.0
X_chaos = chaotic_map(X[0], a, b, c)
for j in range(1, NP):
X_chaos = torch.cat((X_chaos, chaotic_map(X[j], a, b, c)))
X_chaos = torch.reshape(X_chaos, (NP, dim))
for j in range(NP):
# 计算适应度
fit = objective_func(X[j])
if fit < P_fit[j]:
P[j] = X[j].clone()
P_fit[j] = fit
if P_fit[j] < G_fit:
G = P[j].clone()
G_fit = P_fit[j]
# 更新速度和位置
r1, r2 = torch.rand(dim), torch.rand(dim)
V[j] = w * V[j] + c1 * r1 * (P[j] - X[j]) + c2 * r2 * (G - X[j]) + 0.01 * X_chaos[j]
X[j] = X[j] + V[j]
X[j] = torch.clamp(X[j], lb, ub)
return G, G_fit
```
最后,我们可以使用上述算法来优化我们的模型参数。以下是示例代码:
```python
# 定义目标函数
def objective_func(x):
# TODO:根据需要定义适应度函数
return 0.0
# 初始化参数
lb, ub = torch.tensor([0.0, 0.0, 0.0]), torch.tensor([1.0, 1.0, 1.0])
dim, NP, iter_max = 3, 20, 100
w, c1, c2 = 0.5, 1.5, 1.5
# 使用FA_CPSO优化算法迭代更新参数
best_params, best_fit = FA_CPSO(objective_func, lb, ub, dim, NP, iter_max, w, c1, c2)
# 加入萤火虫随机扰动继续优化参数
best_params += 0.01 * torch.randn(dim)
best_fit = objective_func(best_params)
for i in range(10):
params = best_params + 0.01 * torch.randn(dim)
fit = objective_func(params)
if fit < best_fit:
best_params, best_fit = params, fit
print("最优参数为:", best_params)
print("最优适应度为:", best_fit)
```
请注意,这只是一个基本的示例代码,您需要根据自己的需求进行修改。
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