MFDFA {RespirAnalyzer}

MultiFractal Detrended Fluctuation Analysis

Description

Applies the MultiFractal Detrended Fluctuation Analysis (MFDFA) to time series.

Usage

MFDFA(tsx, scale, m, q)

Arguments

tsx

Univariate time series (must be a vector).

scale

Vector of scales.

m

An integer of the polynomial order for the detrending.

q

q-order of the moment.

Value

A list of the following elements:

• Hq q-order Hurst exponent.

• tau_q Mass exponent.

• hq Holder exponent.

• Dq singularity dimension.

• Fqi q-order fluctuation function.

• line linear fitting line of fluctuation function.

References

Zhang T, Dong X, Chen C, Wang D, Zhang XD. RespirAnalyzer: an R package for continuous monitoring of respiratory signals.

Examples

data("TestData") # load Data from TestData dataset
Fs <- 50
Peaks <- find.peaks(Data[,2],Fs,lowpass=TRUE,freq=1,MovingAv=FALSE,
                    W=FALSE,filter=TRUE,threshold=0.05)
head(Peaks)
PP_interval <- diff(Peaks$PeakIndex)/Fs
## Computing Multifractal
exponents=seq(3, 9, by=1/4)
scale=2^exponents
q=-10:10
m=2
Result <- MFDFA(PP_interval, scale, m, q)
Coeff <- fit.model(Result$Hq,q)
print(Coeff)
Para<- -log(Coeff)/log(2)
Para[3]=Para[1]-Para[2]
names(Para)<-c("Hmax","Hmin","DeltaH")
Para

PP_Hq <- Result$Hq
PP_hq <- Result$hq
PP_Dq <- Result$Dq
PP_Para <-Para