The submitted title, "Linear Regression from Scratch", was misleading. We've replaced it with the title on the page.
From-scratchness is relative I guess.
First you need to create a universe...
Easy Biscuits from Scratch:
Step 1) Plant a crop of wheat
Could you explain it like you're explaining to a high school senior?
Yeah, I wonder what the intended audience is. I would guess that if someone is familiar with the notation and concepts introduced, that they would also be quite familiar with linear regression. Nice article nevertheless.