Coursera Machine Learning Study notes (11)

-Polynomial regression

Since linear regression does not apply to all data, sometimes we need to use curves to fit our data, for example, with two-times polynomial:

Or three-time polynomial:

Usually we need to look at the data before deciding what model to try to fit.

After that, we can make:

The two-time polynomial is then converted to a linear regression model.

It is worth noting that if we adopt a polynomial regression model, feature scaling is necessary before the gradient descent algorithm is run.

Coursera Machine Learning Study notes (11)