A fast but unstable orthogonal triangularization technique for Toeplitz matrices
Franklin T. Luk, Sanzheng Qiao · Linear Algebra and its Applications · 1987
D. Sweet's clever QR decomposition algorithm for Toeplitz matrices is considered. It requires only O(n2) flops to factor an n × n matrix. We analyze the algorithm to point out its deficiencies, and compare it against two other Toeplitz solvers.