高斯回归matlab程序,高斯过程回归 - MATLAB & Simulink - MathWorks 中国
时间: 2024-02-13 20:06:31 浏览: 95
好的,您需要一个高斯过程回归的 MATLAB 程序,我可以为您提供一个简单的例子:
```matlab
% 生成训练数据
x_train = linspace(-5, 5, 10)';
y_train = sin(x_train) + 0.1*randn(10,1);
% 定义高斯核函数
sigma_f = 1;
l = 1;
k = @(x1, x2) sigma_f^2 * exp(-(norm(x1 - x2)/l)^2);
% 构建协方差矩阵
K = zeros(length(x_train));
for i = 1:length(x_train)
for j = 1:length(x_train)
K(i,j) = k(x_train(i), x_train(j));
end
end
% 预测新数据
x_test = linspace(-5, 5, 100)';
K_s = zeros(length(x_test), length(x_test));
for i = 1:length(x_test)
for j = 1:length(x_test)
K_s(i,j) = k(x_test(i), x_test(j));
end
end
K_ss = k(x_test, x_test);
K_inv = inv(K);
mu = K_s' * K_inv * y_train;
cov = K_ss - K_s' * K_inv * K_s;
% 绘制结果
figure;
hold on;
plot(x_train, y_train, 'ro');
plot(x_test, mu, 'b-');
fill([x_test; flipud(x_test)], [mu+2*sqrt(diag(cov)); flipud(mu-2*sqrt(diag(cov)))], 'g', 'FaceAlpha', 0.2, 'EdgeAlpha', 0);
xlabel('x');
ylabel('y');
legend('训练数据', '预测', '不确定性');
```
这个例子中,我们首先生成了一些训练数据,然后定义了高斯核函数,接着构建了协方差矩阵,最后用高斯过程回归方法预测了新数据,并绘制了结果。您可以根据自己的需求修改这个程序。
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