Test for R2

[This is a work in progress] R squared is one of many ways to calculate how good a line fits some points. It is widely used in mathematics, statics, machine learning, etc fields. In fact it is not only for points (and one line) in a $\mathbb{R}^2$ (2D planes). The concept works for $n$ dimentions: $\mathbb{R}^n$, it is just that for humans it is easier to understand it in 2D planes.

Finding a line from some points (WIP)

Finding a line that best fits some points is called linear regression. It can be done using severl techniques but the simplest one is by "Linear Regression": So lets assume we have some random points:

pointsX = [(0.5, 0.5)]

Calculating R squared

Toy implementation in Javascript

Python implementation: https://www.geeksforgeeks.org/linear-regression-python-implementation/

What does really mean R squared?

WIP https://www.khanacademy.org/math/statistics-probability/describing-relationships-quantitative-data/more-on-regression/v/calculating-r-squared