A Guide on Spectral Methods Applied to Discrete Data in One Dimension

Figure 11

Calculating the ideal low pass filter. Panel (a) shows the original function (gray line) and the noisy sampling points (open symbols). The result of the ideal low pass filter in the time domain is given in (a) by the solid line. The dashed line in (a) illustrates the low frequency part of the signal with . Panel (b) displays the spectrum of the original function (gray), the filtered result (black), and the spectral kernel function (dashed).

(a) Time domain

(b) Spectral domain