Linear Regression From the Inside

Glossary

An identity matrix — a square matrix with ones on the main diagonal and zeros elsewhere.

An inverse matrix — a square matrix $A$ is a matrix $A$ with a superscript -1 whose product with $A$ is equal to the identity matrix.

Dummy code — a simple code that doesn't mean anything.

Invertible matrices — matrices that have an inverse.

Non-invertible — matrices that don't have an inverse.