R/CPO_scale.R

In mlrCPO: Composable Preprocessing Operators and Pipelines for Machine Learning

#' @title Construct a CPO for Scaling / Centering
#'
#' @template cpo_doc_intro
#'
#' @param center [\code{logical(1)}]\cr
#'   Whether to center the data.
#'   Default is \code{TRUE}.
#' @param scale [\code{logical(1)}]\cr
#'   Whether to scale the data.
#'   Default is \code{TRUE}.
#' @template cpo_doc_outro
#' @export
cpoScale = makeCPOExtendedTrafo("scale",  # nolint
  pSS(center = TRUE: logical, scale = TRUE: logical),
  dataformat = "numeric",
  cpo.trafo = {
    result = scale(as.matrix(data), center = center, scale = scale)
    control = list(center = firstNonNull(attr(result, "scaled:center"), FALSE), scale = firstNonNull(attr(result, "scaled:scale"), FALSE))
    if (!isFALSE(control$scale) && any(control$scale == 0)) {
      result[, control$scale == 0] = 0
      control$scale[control$scale == 0] = 1
    }
    result
  }, cpo.retrafo = {
    scale(as.matrix(data), center = control$center, scale = control$scale)
  })
registerCPO(cpoScale, "data", "numeric data preprocessing", "Center and / or scale the data using base::scale.")