demofox on Nostr: yeah, so you can "least squares fit" points while going through them once, pretty ...

yeah, so you can "least squares fit" points while going through them once, pretty easily. Check this blog post about it. The first section "bilinear surface fitting" is exactly this.
https://blog.demofox.org/2017/01/02/incremental-least-squares-surface-and-hyper-volume-fitting/
It mentions a previous post that starts out with curves, while this one talks about surfaces. This is that post in case helpful for understanding better:
https://blog.demofox.org/2016/12/22/incremental-least-squares-curve-fitting/