R/how_many_images_per_pixel.R

In RobinKohrs/soilmoistr:

#' Mean Pixel value
#'
#' @description Get the mean pixel value for a list of soilmoisture-image paths
#'
#' @importFrom  doFuture registerDoFuture
#'
#' @param sm_image_paths A character vector containing the paths to soilmoisture images
#'
#'
#' @export

how_many_images_per_pixel = function(
  sm_image_paths = NULL
){

  # sum up the times it was not 0
  # registerDoFuture()
  # plan(multisession, workers = 6)
  # sum = foreach(i = seq_along(sm_image_paths),
  #               .combine = "+") %dopar% {
  #
  #                star = read_stars(sm_image_paths[[i]])
  #                star_vals = star[[1]]
  #                star_vals[star_vals == 0] = 0 # unnecessary
  #                star_vals[star_vals > 0] = 1
  #                star_vals
  #               }
  #
  # # read in the first image
  # dummy = read_stars(sm_image_paths[[1]])
  # dummy[[1]] = sum
  #

  sum = read_stars(sm_image_paths[[1]])[[1]]
  for (i in seq_along(sm_image_paths)) {
    if (i != 1) {
      cat("\r", i, "/", length(sm_image_paths))
      star = read_stars(sm_image_paths[[i]])
      star_vals = star[[1]]
      star_vals[star_vals == 0] = 0 # unnecessary
      star_vals[star_vals > 0] = 1
      sum = sum + star_vals
    }
  }


  # read in the first image
  dummy = read_stars(sm_image_paths[[1]])
  dummy[[1]] = sum


  # return the dummy stars object with the computed values
  return(dummy)

}