Figure 1From: Dynamical density delay maps: simple, new method for visualising the behaviour of complex systems Time series graph (left), histogram (center) and Poincaré plot (right) of the interbeat interval [RR(n)] time series derived from an electrocardiographic recording of a healthy subject during sleep (top) and from a randomized/shuffled sequence of these intervals (bottom). Note that the histogram of the shuffled time series is identical to that of the original one, while the Poincaré plot is substantially altered (see text).Back to article page