灰狼优化ANN进行预测,写出相关代码
时间: 2023-08-11 13:35:46 浏览: 91
这里提供一个使用灰狼优化算法优化ANN进行预测的示例代码:
```
import numpy as np
import random
# 定义灰狼优化算法函数
def grey_wolf_optimizer(obj_func, dim, lb, ub, SearchAgents_no, Max_iter):
Alpha_pos = np.zeros(dim)
Alpha_score = float("inf")
Beta_pos = np.zeros(dim)
Beta_score = float("inf")
Delta_pos = np.zeros(dim)
Delta_score = float("inf")
Positions = np.zeros((SearchAgents_no, dim))
for i in range(dim):
Positions[:, i] = np.random.uniform(0, 1, SearchAgents_no) * (ub[i] - lb[i]) + lb[i]
Convergence_curve = np.zeros(Max_iter)
for l in range(0, Max_iter):
for i in range(0, SearchAgents_no):
# 计算适应度函数值
fitness = obj_func(Positions[i, :])
# 更新 Alpha, Beta, Delta
if fitness < Alpha_score:
Alpha_score = fitness
Alpha_pos = Positions[i, :]
if (fitness > Alpha_score) and (fitness < Beta_score):
Beta_score = fitness
Beta_pos = Positions[i, :]
if (fitness > Alpha_score) and (fitness > Beta_score) and (fitness < Delta_score):
Delta_score = fitness
Delta_pos = Positions[i, :]
a = 2 - l * ((2) / Max_iter)
for i in range(0, SearchAgents_no):
for j in range(0, dim):
r1 = random.random()
r2 = random.random()
A1 = 2 * a * r1 - a
C1 = 2 * r2
D_alpha = abs(C1 * Alpha_pos[j] - Positions[i, j])
X1 = Alpha_pos[j] - A1 * D_alpha
r1 = random.random()
r2 = random.random()
A2 = 2 * a * r1 - a
C2 = 2 * r2
D_beta = abs(C2 * Beta_pos[j] - Positions[i, j])
X2 = Beta_pos[j] - A2 * D_beta
r1 = random.random()
r2 = random.random()
A3 = 2 * a * r1 - a
C3 = 2 * r2
D_delta = abs(C3 * Delta_pos[j] - Positions[i, j])
X3 = Delta_pos[j] - A3 * D_delta
Positions[i, j] = (X1 + X2 + X3) / 3
Convergence_curve[l] = Alpha_score
return Alpha_pos, Alpha_score, Convergence_curve
# 定义适应度函数
def fitness_func(x):
# 实现 ANN 预测适应度函数
# ...
# 返回预测误差
return error
# 确定 ANN 权重和偏置的维度和取值范围
dim = 100
lb = [-1] * dim
ub = [1] * dim
# 运行灰狼优化算法
Alpha_pos, Alpha_score, Convergence_curve = grey_wolf_optimizer(fitness_func, dim, lb, ub, 100, 100)
# 输出结果
print("优化后的权重和偏置:", Alpha_pos)
print("预测误差:", Alpha_score)
```
需要注意的是,上述代码中的 `fitness_func` 函数需要根据具体的问题进行实现,以计算 ANN 预测的误差。同时,还需要根据 ANN 的实际情况确定权重和偏置的维度和取值范围。
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