R/rundown_correction.R

In tdanker/ephys2: Read, analyze and plot HEKA Patchmaster files

#' run-down correction methods
#' 
#'  
#' @param x, usually the time values of an i/t plot
#' @param y, usually the results of a cursor method, as they appear in an i/T plot
#' @seealso to be used with \link{plotIt}
#'
#' @name rundowncorrection
NULL

#' @describeIn rundowncorrection 
#' usues an lm fit over the region defined by 'subset' for rundown correction
#' @param subset  region of the i/t plot to be used for fitting and/or anchoring of run down correction
#' @export
rundown_lm<-function(x,y, subset,...){
  m=lm(y~x, subset=subset)
  y_<-predict(m, as.data.frame(x))

  lines(y_~x)
  points(x[subset], y[subset], col="red", pch=13 )
  y_corr=y[subset[1]]*y/y_
  points(x,y_corr, col="blue")
  y_corr
}

#' @describeIn rundowncorrection 
#' usues a fixed slope defined by 'slope', and anchored at 'subset[1]', for rundown correction 
#' @param slope  the slope of a linear rundown correction
#' @export
rundown_fix<-function(x,y, subset, slope,...){
  plot(x,y, col="grey80", ...)
  y_<-y+((1:length(y))*slope)
  
  lines(y_~x)
  points(x[subset], y[subset], col="red", pch=13 )
  y_corr=y_
  points(x,y_corr, col="blue")
  y_corr
}