I have x,y coordinates. They are arranged at fixed intervals of 1 unit along the x axis. The Y values are arbitrary. I want to draw smooth curvy line that passes through all of them. Or rather, I want a formula to find the y for any value of x for the hypothetical line.
Here are a few methods you can use:
Simply interpolate them using a bunch of quadratics. The resulting curve will have discontinuous 2nd derivative.
Discrete Fourier transform