Seems like GE on a 2x2 matrix should be pretty darn fast.... especially if you use scalar * vector type operations.

Abstract Let A be an n × n Hermitian matrix and A = UΛUH be its spectral decomposition, where U is a unitary matrix of order n and Λ is a diagonal matrix. In this note we present the perturbation ...

One of the essential dilemmas in our lives is choosing between what is urgent and what is important. Years ago, Stephen Covey placed both issues on a 2x2 matrix, giving new light by having us consider ...