Delay in the Detrended Fluctuation Analysis Crossover Point as a Risk Factor for Type 2 Diabetes Mellitus

Figure 2

To calculate the crossover point, a set of pairs of linear regression lines are built with several combinations of points: points 1–4 for the first limb and 5 : 16 for the second, then 1 : 5 and 6 : 16, then 1 : 6 and 1 : 16, and so on until 1 : 11 and 12 : 16. A combined is calculated for each pair of regression lines, and the best-fit pair is assumed to be the best representation of the time series. In this figure, the shade of the regression lines represents the goodness of fit (darker grey: better fit). The best fit is represented by a solid line. The abscissa of the intersection between both limbs is the crossover point (represented as log(number of measurements per window)). To obtain the time (in minutes) for a value , crossover (minutes) = .