(a) Time domain
(b) Frequency domain
Figure 9: Comparison between and in time and frequency domains. (a) (red) and its projection (blue) are shown for several values of and in the time domain. rad/s, rad/s and rad/s in the top, middle and bottom row, respectively. The period is fixed at s in the left column and s in the right column. (b) Fourier amplitude spectra of (red) and (blue) for the same values of and as in (a). Note that the differentiating filter clearly removes the zero-frequency (dc) coefficient corresponding to in all cases.