RHRV (version 5.0.0)

EstimatePSDSlope: Estimate the slope of the Power Spectral Density (PSD).

Description

Estimate the slope of the Power Spectral Density (PSD) of the RR time series.

Usage

EstimatePSDSlope(
  HRVData,
  indexFreqAnalysis = length(HRVData$FreqAnalysis),
  indexNonLinearAnalysis = length(HRVData$NonLinearAnalysis),
  regressionRange = NULL,
  doPlot = T,
  main = "PSD power law",
  xlab = "Frequency (Hz)",
  ylab = "Spectrum",
  pch = NULL,
  log = "xy",
  ...
)

Value

The EstimatePSDSlope returns the HRVData structure containing a PSDSlope field storing the spectral index and the proper Hurst exponent.

Arguments

HRVData

Data structure that stores the beats register and information related to it.

indexFreqAnalysis

An integer referencing the periodogram that will be used for estimating the spectral index.

indexNonLinearAnalysis

An integer referencing the structure that will store the resulting estimations.

regressionRange

Range of frequencies in which the regression will be performed. Default is c(1e-4, 1e-2) Hz.

doPlot

Plot the periodogram and the least-squares fit?

main

Title for the plot.

xlab

Title for the x axis.

ylab

Title for the y axis.

pch

Symbol for the plotting points.

log

A character string which contains "x" if the x axis is to be logarithmic, "y" if the y axis is to be logarithmic and "xy" or "yx" if both axes are to be logarithmic (default).

...

Other arguments for the plotting function.

Details

The power spectrum of most physiological signals fulfils \(S(f)=Cf^{-\beta}\) (1/f spectrum). This function estimates the \(\beta\) exponent, which is usually referred to as the spectral index.

References

Voss, Andreas, et al. "Methods derived from nonlinear dynamics for analysing heart rate variability." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 367.1887 (2009): 277-296.

Eke, A., Herman, P., Kocsis, L., & Kozak, L. R. (2002). Fractal characterization of complexity in temporal physiological signals. Physiological measurement, 23(1), R1.

See Also

spectrum,lsp, CalculatePSD.

Examples

if (FALSE) {
data(HRVProcessedData)
# use other name for convenience
HRVData=HRVProcessedData
# Estimate the periodogram
HRVData=CreateFreqAnalysis(HRVData)
HRVData=CalculatePSD(HRVData,1,"pgram",doPlot = T,log="xy")
HRVData=CreateNonLinearAnalysis(HRVData)
HRVData=SetVerbose(HRVData,T)
HRVData=EstimatePSDSlope(HRVData,1,1,
                        regressionRange=c(5e-4,1e-2))
}