I know about DFT (one of the special cases), but for fitting general polynomials it has numerical problems, and in any case solving a linear system may not be as efficient as using eg orthogonal families, which are incidentally better conditioned.
I know about DFT (one of the special cases), but for fitting general polynomials it has numerical problems, and in any case solving a linear system may not be as efficient as using eg orthogonal families, which are incidentally better conditioned.