1. A method for analyzing one or more order components from an input signal acquired from a mechanical system containing a rotating apparatus, the method comprising: receiving samples of the input signal; performing an invertible joint time-frequency transform on the samples of the input signal to produce a first array of coefficients which depend on time and frequency; constructing an order mask array in response to user input; masking the first array of coefficients with the order mask array to generate a second array of coefficients which depend on time and frequency; generating a time domain signal from the second array of coefficients; and presenting the time domain signal to a user on a presentation device; wherein the time domain signal is useable in analyzing the mechanical system.