would suffice as well. Polyfit is a bit higher quality code too, and it comes with MATLAB since the last 30 years or so. And polyfit has much more capability.
I do find it somewhat laughable that the code fits a QUADRATIC polynomial, but the picture posted shows a curve fit through 4 points, that is clearly NOT quadratic. Hey, it is that new math I suppose. What will they think of next?
And finally, while the title of the submission says something about interpolation, it does no interpolation for you at all.