secant {DFA} | R Documentation |
Applies the secant method for detection of crossover points on the log-log curve.
secant(x,y,npoint,size_fit)
x |
Vector of the decimal logarithm of the boxes sizes. |
y |
Vector of the decimal logarithm of the DFA calculated in each boxe. |
npoint |
Number of crossover points calculated on the log-log curve. |
size_fit |
Number of points of the two semi-curved fitted in the extremes of the log-log curve. |
position |
Position of the crossover point identified by the secant method. |
Victor Barreto Mesquita
# Example with the data referring to the log fluctuation #channel curve data calculated for an epileptic subject #extracted in the Physionet platform. library(DFA) data("EEGsignal") x<-EEGsignal$`log10(boxes)` y<-EEGsignal$`log10(DFA)` plot(x,y,xlab="log10(boxes)",ylab="log10(DFA)") secant(x,y,npoint=2,size_fit=8) # Example with crossover point fixed in position=20. library(DFA) part1 <- seq(1,20) part2 <- seq(20,1) y = c(part1,part2) x<-seq(1,40) plot(x,y) secant(x,y,npoint=1,size_fit=8)