R/CalculateFracDim.R

In RHRV: Heart Rate Variability Analysis of ECG Data

CalculateFracDim <-
function(HRVData, indexNonLinearAnalysis = length(HRVData$NonLinearAnalysis),
         m=10, tau=3, Cra=0.005, Crb=0.75, N=1000, verbose=NULL) {
# -------------------------------------
# Calculates Fractal Dimension
# -------------------------------------
  # Using paste in order to maintain the line format 
  .Deprecated("CalculateCorrDim")
  
  HRVData = HandleVerboseArgument(HRVData, verbose)
  
  npoints = length(HRVData$Beat$niHR)
  if (npoints > N) {
	  DataInt = HRVData$Beat$niHR[(npoints / 2 - N / 2):(npoints / 2 + N / 2)] 
	} else{
	  DataInt = HRVData$Beat$niHR
	}
	
	randC = CalculateRfromCorrelation(HRVData, DataInt, m=m, tau=tau, Cra=Cra, Crb=Crb)
	ra = randC[1,1]
	rb = randC[1,2]
	Cmra = randC[2,1]
	Cmrb = randC[2,2]
		
	VerboseMessage(HRVData$Verbose, "Calculating Fractal Dimension")
	
	FracDim = (log(Cmrb) - log(Cmra)) / (log(rb) - log(ra))
	VerboseMessage(HRVData$Verbose, paste("Fractal Dimension:", FracDim))
	HRVData$NonLinearAnalysis[[indexNonLinearAnalysis]]$FracDim=FracDim
    
	return(HRVData)
}