Thank you for the kind words!

This was meant to be a new year greeting post for Jan 1st. I started it in Dec, but wandered away to other things. (On the good side, I finished it before the Lunar New Year :D)

Was thinking of you. Today's the day (the 12th).

So.

Happy Chinese New Year, dear Sylvia! :D

I don't understand a bit of it, too advanced and sophisticated for me. Anyway, beautiful work, very impressive!

How long did you take from scratch to completion?

Hi Christophe, thank you! The visualization should use the settings from B-spline basis section, i.e.

$bsDegree=3;
$CPtsNum=4;
$bsKnot={ConstantArray[0,$bsDegree],Range[$CPtsNum-$bsDegree+1]//Rescale,ConstantArray[1,$bsDegree]}//Flatten;

They were reset in Solve the fitting problem section, then I forgot to set them back for the visualization.

Sorry for the inconvenience and thank you for catching the bug! I'll update the notebook tomorrow.