Andrew Ng机器学习笔记#3
Logistic regression
- Hypothesis function and definition:
Therefore, the final form of the hypothesis function shall look like this:
2. Decision boundary:
3.Cost function:
4.Gradient descent：
Notice that this is exactly the same as that of the linear regression.
This vectorized implementation is very useful and convenient to express in Matlab & octave.
5.Multiclass classification: