Summary
Frequency-based determination of stability of periodic solutions is often carried out using Hill's method. The authors recently introduced a novel projection method which uses this Hill matrix to arrive at the Floquet multipliers of the periodic solution in a numerically efficient manner. In this work, we illustrate how a certain nontrivial choice of projection, in conjunction with explicit consideration of subharmonic frequencies in the Hill matrix, can further improve the accuracy while still retaining low computational effort. The Duffing oscillator is presented as a numerical illustration of these properties.
