R/getAverageOfTimeSeries.R

In stnava/ANTsR: ANTs in R: Quantification Tools for Biomedical Images

#' @title getAverageOfTimeSeries
#' @description  Returns a 3D average of a 4D time series.
#' @usage getAverageOfTimeSeries(img)
#' @param img input 4D image
#' @return 3D ants image is output
#' @author Avants BB
#' @examples
#' img <- as.antsImage(array(data = rep(0, 10^4), dim = c(10, 10, 10, 10)))
#' avg <- getAverageOfTimeSeries(img)
#' @export getAverageOfTimeSeries
getAverageOfTimeSeries <- function(img) {
  if (nargs() == 0) {
    return(1)
  }
  myilist <- splitNDImageToList(img)
  averageImage <- myilist[[1]]
  for (i in 2:length(myilist)) {
    averageImage <- averageImage + myilist[[i]]
  }
  return(averageImage / length(myilist))
}