logistic regression cost function(single example)
图像分布
logistic regression cost function(m examples)
Writting cost function in a more convenient form with just one line
To fit parameter θ
Using gradient descent to minimize cost function
看上去和gradient descent for linear regression是一样的,但是其实只是形式一至,hθ(x)不一样,如上图所示,蓝色的hθ(x)为linear regression的,红色的为logistic regression