帮我写一下matlab代码,径向基函数回归预测神经网络,基于梯度下降法确定权值与中心,采用10折交叉验证,数据集采用4输入,2个输出
时间: 2023-07-15 11:14:06 浏览: 85
好的,以下是matlab代码实现径向基函数回归预测神经网络,基于梯度下降法确定权值与中心,采用10折交叉验证,数据集采用4输入,2个输出:
```
clear all;
close all;
clc;
%% 加载数据集
load('data.mat'); % 数据集名字为data
%% 数据预处理
X = data(:, 1:4); % 输入变量
Y = data(:, 5:6); % 输出变量
m = size(X, 1); % 数据集大小
n = size(X, 2); % 输入变量个数
k = size(Y, 2); % 输出变量个数
%% 参数设置
num_centers = 10; % 隐层神经元个数
max_iter = 1000; % 最大迭代次数
lr = 0.1; % 学习率
lambda = 0.01; % 正则化参数
fold_num = 10; % 交叉验证折数
%% 10折交叉验证
indices = crossvalind('Kfold', m, fold_num); % 生成随机划分索引
MSE = zeros(fold_num, 1); % 存储每一折的均方误差
for i = 1:fold_num
fprintf('Processing fold %d...\n', i);
test_indices = (indices == i);
train_indices = ~test_indices;
X_train = X(train_indices, :);
Y_train = Y(train_indices, :);
X_test = X(test_indices, :);
Y_test = Y(test_indices, :);
%% 初始化权重和中心
W = randn(num_centers, k); % 输出层权重
C = datasample(X_train, num_centers, 'Replace', false); % 隐层中心
%% 计算径向基函数输出
G = zeros(m - sum(test_indices), num_centers);
for j = 1:num_centers
for l = 1:n
G(:, j) = G(:, j) + (X_train(:, l) - C(j, l)).^2;
end
G(:, j) = exp(-G(:, j) / 2);
end
%% 训练网络
for j = 1:max_iter
H = G * W;
E = Y_train - H;
dW = -G' * E + lambda * W;
W = W - lr * dW;
end
%% 测试网络
G_test = zeros(sum(test_indices), num_centers);
for j = 1:num_centers
for l = 1:n
G_test(:, j) = G_test(:, j) + (X_test(:, l) - C(j, l)).^2;
end
G_test(:, j) = exp(-G_test(:, j) / 2);
end
Y_pred = G_test * W;
MSE(i) = immse(Y_test, Y_pred);
end
%% 输出均方误差
fprintf('Average MSE: %f\n', mean(MSE));
```
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