Hands-On Data Science with Anaconda

Model selection

When finding a good model, sometimes we face under fitting and over fitting. The first example is borrowed; you can download the program at http://scikit-learn.org/stable/auto_examples/model_selection/plot_underfitting_overfitting.html#sphx-glr-auto-examples-model-selection-plot-underfitting-overfitting-py. It demonstrates the problems of under fitting and over fitting and how we can use linear regression with polynomial features to approximate nonlinear functions. The true function is given here:

In the following program, we try to use linear and polynomial models to approximate the equation. The slightly modified code is ...