用粒子群优化高斯过程回归预测python代码
时间: 2023-09-03 10:12:12 浏览: 73
以下是使用粒子群优化高斯过程回归进行预测的Python代码示例:
```python
import numpy as np
import GPy
from pyswarm import pso
# Define the function to be optimized using PSO
def optimize_gp_params(params, X, Y):
kernel = GPy.kern.RBF(1, variance=params[0], lengthscale=params[1])
model = GPy.models.GPRegression(X, Y, kernel)
return model.log_likelihood()
# Load the data
data = np.loadtxt('data.csv', delimiter=',')
X = data[:, 0].reshape((-1, 1))
Y = data[:, 1].reshape((-1, 1))
# Set the bounds for the optimization parameters
bounds = [(1e-5, 1e5), (1e-5, 1e5)]
# Use PSO to find the optimal hyperparameters for the Gaussian process
params_opt, f_opt = pso(optimize_gp_params, bounds, args=(X, Y))
# Train the GP model with the optimal hyperparameters
kernel_opt = GPy.kern.RBF(1, variance=params_opt[0], lengthscale=params_opt[1])
model = GPy.models.GPRegression(X, Y, kernel_opt)
# Make predictions with the GP model
X_test = np.linspace(0, 10, 100).reshape((-1, 1))
Y_pred, Y_var = model.predict(X_test)
# Plot the results
import matplotlib.pyplot as plt
plt.plot(X, Y, 'bo', markersize=8)
plt.plot(X_test, Y_pred, 'r-', linewidth=2)
plt.fill_between(X_test[:, 0], Y_pred[:, 0] - 2*np.sqrt(Y_var[:, 0]), Y_pred[:, 0] + 2*np.sqrt(Y_var[:, 0]), color='gray', alpha=0.2)
plt.xlabel('X')
plt.ylabel('Y')
plt.show()
```
该代码使用PSO算法来优化高斯过程回归中的方差和长度尺度参数,并使用优化后的参数来训练GP模型并进行预测。最终结果将绘制在一个图形中。
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