Application of the Lomb-Scargle Periodogram to InvestigateHeart Rate Variability during Haemodialysis

Figure 4

Illustration of the effect of reducing the number of points in the LS periodogram estimate. The lower pane shows that the LF/HF ratio is relatively well estimated using only 41% of the available data, but the window limit is reached when 20% of the data is discarded, shown in the upper pane.

(a)

(b)