R/transformers.R

In alphaci: Confidence Intervals for Coefficient Alpha and Standardized Alpha

get_transformer <- function(transform) {
  transformers <- list(
    fisher = transformer_fisher,
    none = transformer_none,
    arcsin = transformer_arcsin,
    log = transformer_log
  )

  if (transform %in% names(transformers)) {
    transformers[[transform]]
  } else {
    stop(paste0("`transformer = ", transform, "` not supported."))
  }
}

transformer_fisher <- c(
  est = \(est) atanh(est),
  sd = \(est, sd) sd / (1 - est^2),
  inv = tanh
)

transformer_log <- c(
  est = \(est) log(1 - est),
  sd = \(est, sd) sd / abs(1 - est),
  inv = \(x) 1 - exp(x)
)

transformer_none <- c(
  est = \(est) est,
  sd = \(est, sd) sd,
  inv = \(x) x
)

transformer_arcsin <- c(
  est = asin,
  sd = \(est, sd) sd / sqrt(1 - est^2),
  inv = sin
)