stats-f-tbl.R

#' Distribution Statistics
#'
#' @family F Distribution
#' @family Distribution Statistics
#'
#' @author Steven P. Sanderson II, MPH
#'
#' @details This function will take in a tibble and returns the statistics
#' of the given type of `tidy_` distribution. It is required that data be
#' passed from a `tidy_` distribution function.
#'
#' @description Returns distribution statistics in a tibble.
#'
#' @param .data The data being passed from a `tidy_` distribution function.
#'
#' @examples
#' library(dplyr)
#'
#' tidy_f() |>
#'   util_f_stats_tbl() |>
#'   glimpse()
#'
#' @return
#' A tibble
#'
#' @export
#'

util_f_stats_tbl <- function(.data) {

  # Immediate check for tidy_ distribution function
  if (!"tibble_type" %in% names(attributes(.data))) {
    rlang::abort(
      message = "You must pass data from the 'tidy_dist' function.",
      use_cli_format = TRUE
    )
  }

  if (attributes(.data)$tibble_type != "tidy_f") {
    rlang::abort(
      message = "You must use 'tidy_f()'",
      use_cli_format = TRUE
    )
  }

  # Data
  data_tbl <- dplyr::as_tibble(.data)

  atb <- attributes(data_tbl)

  stat_mean <- ifelse(atb$.df2 > 2, (atb$.df2 / (atb$.df2 - 2)), "undefined")
  stat_median <- "Not computed"
  stat_mode <- ifelse(
    atb$.df1 > 2,
    ((atb$.df2 * (atb$.df1 - 2)) / (atb$.df1 * (atb$.df2 + 2))),
    "undefined"
  )
  stat_range <- "0 to Inf"
  stat_sd <- ifelse(
    atb$.df2 > 4,
    sqrt((2 * (atb$.df2)^2 * (atb$.df1 + atb$.df2 - 2)) /
      (atb$.df1 * (atb$.df2 - 2)^2 * (atb$.df2 - 4))),
    "undefined"
  )
  stat_coef_var <- ifelse(
    atb$.df2 > 4,
    sqrt((2 * (atb$.df1 + atb$.df2 - 2)) / (atb$.df1 * (atb$.df2 - 4))),
    "undefined"
  )
  stat_skewness <- ifelse(
    atb$.df2 > 6,
    ((2 * atb$.df1 + atb$.df2 - 2) * sqrt(8 * (atb$.df2 - 4))) /
      (sqrt(atb$.df1) * (atb$.df2 - 6) * sqrt(atb$.df1 + atb$.df2 - 2)),
    "undefined"
  )
  stat_kurtosis <- "Not computed"

  # Data Tibble
  ret <- dplyr::tibble(
    tidy_function = atb$tibble_type,
    function_call = atb$dist_with_params,
    distribution = dist_type_extractor(atb$tibble_type),
    distribution_type = atb$distribution_family_type,
    points = atb$.n,
    simulations = atb$.num_sims,
    mean = stat_mean,
    median = stat_median,
    mode = stat_mode,
    std_dv = stat_sd,
    coeff_var = stat_coef_var,
    skewness = stat_skewness,
    kurtosis = stat_kurtosis,
    computed_std_skew = tidy_skewness_vec(data_tbl$y),
    computed_std_kurt = tidy_kurtosis_vec(data_tbl$y),
    ci_lo = ci_lo(data_tbl$y),
    ci_hi = ci_hi(data_tbl$y)
  )

  # Return
  return(ret)
}