It is conjectured that mathematical transform methods may be deserving of increased awareness in systems analysis in general, and power quality calculations in particular, due to their favorable convolution property when studying linear, time-invariant systems. Because certain transforms have associated with them a fast algorithm for digital computation, frequency-domain analysis tools can substantially lessen the computational burden when solving for the response to a known system and input. Two elementary examples are included whereby the steady-state system response to nonsinusoidal load currents is calculated using the Hartley and Walsh transforms. A comparison between the fast Fourier transform (FFT) and conventional time-domain convolution by lagged products is presented. Also, the authors present a brief introduction to the Mellin transform and its application to Euler linear, time-varying differential equations.