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

Figure 3

(a, b) The signal is sampled marginally. In (c, d), it is undersampled so the upper and lower parts of the spectrum infiltrate each other. Compare the filled symbols, which correspond to the points in the lower half plane of (b). The black line in (c) indicates the alternative reconstruction.

(a)

(b)

(c)

(d)