I'm a fan of the three parameter sign fit https://ieeexplore.ieee.org/document/469117 https://ieeexplore.ieee.org/document/469117. Sorry for the paywall. Essent

I'm a fan of the three parameter sign fit https://ieeexplore.ieee.org/document/469117 https://ieeexplore.ieee.org/document/469117. Sorry for the paywall. Essentially if you want to fit a sinusoid to some data, and know the frequency, you can transform it into a linear least squares problem. If anyone is interested I can type up the math when I'm not on mobile, it's pretty straightforward. Honorable mention: Kahan summation algorithm https://en.m.wikipedia.org/wiki/Kahan_summation_algorithm https://en.m.wikipedia.org/wiki/Kahan_summation_algorithm