geposan/R/method_proximity.R

#' Score the distance of genes to the telomeres across species.
#'
#' A score will be given to each gene such that 0.0 corresponds to the maximal
#' distance across all genes and 1.0 corresponds to a distance of 0.
#'
#' @param summarize A function for combining the different proximities into one
#'   metric. By default, [stats::median()] is used. Other suggested options
#'   include [min()] and [mean()].
#'
#' @return An object of class `geposan_method`.
#'
#' @export
proximity <- function(summarize = stats::median) {
  method(
    id = "proximity",
    name = "Proximity",
    description = "Proximity to telomeres",
    function(preset, progress) {
      species_ids <- preset$species_ids
      gene_ids <- preset$gene_ids

      cached("proximity", c(species_ids, gene_ids), {
        # Prefilter distances by species and gene.
        data <- geposan::distances[
          species %chin% preset$species_ids &
            gene %chin% preset$gene_ids
        ]

        # Compute the score as described above.
        data <- data[,
          .(combined_distance = as.double(summarize(distance))),
          by = "gene"
        ]

        # Normalize scores.
        data[, score := 1 - combined_distance / max(combined_distance)]

        progress(1.0)

        result(
          method = "proximity",
          scores = data[, .(gene, score)],
          details = list(data = data)
        )
      })
    }
  )
}