Figure 2

Effect of the length of the section on the result series values Z. In the top row, the original series (X), and in the lower rows the resulting Z variables, using sections with different lengths. In A, X is a sinusoidal function with period T = 12. The graphs below, show the mean value calculated with a step s = 1, and l values of 3 T/4, T and 5 T/4. Although the real mean remains constant, for different values of l, an oscillation is present. In B, X is a sinusoidal function with period T = 12 with a phase delay in the middle of the series. In the lower graphs the phases calculated with sections of length T, 2 T and 4 T, are shown. A smoothing of the real phase shift is visible when increasing the length of the section.