能帮我编一段matlab使用knn进行回归
时间: 2023-03-29 15:03:37 浏览: 128
Matlab实现KNN K近邻多输入回归预测(完整源码和数据)
5星 · 资源好评率100%
当然可以,以下是一段使用 MATLAB 进行 KNN 回归的代码:
% 导入数据
data = csvread('data.csv');
X = data(:, 1:end-1);
y = data(:, end);
% 分割数据集
[trainInd, valInd, testInd] = dividerand(size(X, 1), .6, .2, .2);
X_train = X(trainInd, :);
y_train = y(trainInd);
X_val = X(valInd, :);
y_val = y(valInd);
X_test = X(testInd, :);
y_test = y(testInd);
% 标准化数据
mu = mean(X_train);
sigma = std(X_train);
X_train = (X_train - mu) ./ sigma;
X_val = (X_val - mu) ./ sigma;
X_test = (X_test - mu) ./ sigma;
% 训练 KNN 模型
k = 5;
mdl = fitcknn(X_train, y_train, 'NumNeighbors', k);
% 预测并计算误差
y_pred = predict(mdl, X_test);
mse = mean((y_pred - y_test).^2);
% 输出结果
fprintf('KNN 回归的均方误差为 %.4f\n', mse);
阅读全文