R/LoadBeatAscii.R

In RHRV: Heart Rate Variability Analysis of ECG Data

LoadBeatAscii <- function (HRVData, RecordName, RecordPath=".", scale = 1, starttime=NULL, endtime=NULL, datetime = "1/1/1900 0:0:0", verbose = NULL) {
  #-------------------------------
  # Loads beats from an ASCII file
  #-------------------------------
  #	RecordName -> file containing values
  #	RecordPath -> path
  #-------------------------------
  
  HRVData = HandleVerboseArgument(HRVData, verbose)
  
  VerboseMessage(HRVData$Verbose, 
                 paste("Loading beats positions for record:", RecordName))
  
  
  if ( (!is.null(starttime) & is.null(endtime) ) | ( is.null(starttime) & !is.null(endtime) ) ) {
    stop("Bad specification of starttime and endtime")
  }
  
  if (!is.null(starttime) & !is.null(endtime)) {
    if ( (starttime<0) | (endtime<0) | (starttime > endtime) ) {
      stop("Bad specification of starttime and endtime")
    }
  }
  
  dir = getwd()
  on.exit(setwd(dir))
  VerboseMessage(HRVData$Verbose, paste("Path:", RecordPath))
  VerboseMessage(HRVData$Verbose, paste("Scale:", scale))
  
  setwd(RecordPath)
  
  x = read.table(RecordName)
  beatsaux = x$V1
  beats = beatsaux[!duplicated(beatsaux)]
  if (length(beatsaux) != length(beats)) {
    VerboseMessage(HRVData$Verbose, 
                   paste("Removed", length(beatsaux) - length(beats),
                         "duplicated beats")
    )
  }
  
  if (!is.null(starttime)) {
    lastbeattime = tail(beats,n=1)
    if (endtime > lastbeattime)  {
      stop("Endtime exceeds record length")
    }
    beats <- beats[beats>=starttime & beats<=endtime]
    VerboseMessage(HRVData$Verbose, paste("Init time:", starttime))
    VerboseMessage(HRVData$Verbose, paste("End time:", endtime))
  }
  
  datetimeaux = strptime(datetime, "%d/%m/%Y %H:%M:%S")
  if (is.na(datetimeaux)) {
    stop("Date/time format is dd/mm/yyyy HH:MM:SS")
  }
  VerboseMessage(HRVData$Verbose,
                 c(paste("Date: ", 
                         sprintf("%02d", datetimeaux$mday), "/", 
                         sprintf("%02d", 1 + datetimeaux$mon), "/", 
                         1900 + datetimeaux$year, "\n"),
                   paste("Time: ", 
                         sprintf("%02d", datetimeaux$hour), ":", 
                         sprintf("%02d", datetimeaux$min), ":", 
                         sprintf("%02d", datetimeaux$sec))
                 )
  )  
  
  HRVData$datetime = datetimeaux
  HRVData$Beat = data.frame(Time = beats * scale)
  VerboseMessage(HRVData$Verbose,  
                 paste("Number of beats:", length(HRVData$Beat$Time)))
  
  return(HRVData)
}