What is this?
There's lots of information online and in text books about linear algebra. This is a collection of that information with context that's quite specific to astronomy, meaning that we're going to be building towards explorations of real data, how to build models for actual problems, and discussing how some published noise models in astronomy work. Fitting linear models is how I do any low-grade 'magic' in astronomy, so I want to put some thoughts down to enable other people to do the same.
Click here to go to the materials at https://christinahedges.github.io/BuildingFastLinearModels.