吴恩达机器学习第六周编程作业ex5答案linearRegCostFunction.m
J =1/(2* m)*sum((X * theta - y).^2)+ lambda /(2* m)*(sum(theta .* theta)-theta(1)*theta(1));
gradient =1/ m * X' *(X * theta - y);%没有sum
grad = gradient + lambda / m * theta;
lambda编程grad(1)=gradient(1);
learningCurve.m
n =size(Xval,1);
for i =1:m
theta =trainLinearReg(X(1:i,:),y(1:i,:), lambda);
error_train(i)=1/(2* i)*sum((X(1:i,:)* theta -y(1:i,:)).^2);
error_val(i)=1/(2* n)*sum((Xval * theta - yval).^2);
end
polyFeatures.m
for i =1:p
X_poly(:,i)= X .^ i;
end
validationCurve.m
m =size(X,1);
n =size(Xval,1);
for i =1:length(lambda_vec)
lambda =lambda_vec(i);
theta =trainLinearReg(X, y, lambda);
error_train(i)=1/(2* m)*sum((X * theta - y).^2);
error_val(i)=1/(2* n)*sum((Xval * theta - yval).^2);
end

版权声明：本站内容均来自互联网，仅供演示用，请勿用于商业和其他非法用途。如果侵犯了您的权益请与我们联系QQ:729038198，我们将在24小时内删除。