R/get_gini.R

In PIP-Technical-Team/wbpip: What the Package Does (One Line, Title Case)

# Add global variables to avoid NSE notes in R CMD check
if (getRversion() >= "2.15.1") {
  utils::globalVariables(
    c(".")
  )
}

#' Gini coefficient
#'
#' Compute the Gini coefficient.
#'
#' @param .data Household survey data frame with at least a welfare variable.
#' @inheritParams compute_pip_stats
#' @param distribution_type character: Type of distribution, either micro,
#'   group, aggregate or imputed.
#' @param weight numeric: expansion population factor.
#'
#' @return data.table
#' @export
get_gini <- function(.data, welfare, weight,
                     distribution_type =
                       c("micro", "group", "aggregate", "imputed")) {

  # Match arg
  distribution_type <- match.arg(distribution_type)

  if (inherits(.data, "grouped_df")) {

    # Organize argument to parse to md_clean_data
    args_in <- list(
      welfare = substitute(welfare),
      weight = substitute(weight),
      distribution_type = distribution_type
    )

    return(dplyr::do(
      .data,
      do.call(get_gini, c(list(.data = .), args_in))
    ))
  }

  # Check arguments
  welfare <- deparse(substitute(welfare))
  weight <- deparse(substitute(weight))

  # Organize argument to parse to md_clean_data
  args <- list(
    dt = .data,
    welfare = welfare,
    weight = weight
  )

  if (distribution_type == "micro") {
    # Clean data
    df <- do.call(md_clean_data, args)$data

    # Compute Gini
    gini <- md_compute_gini(df[[welfare]], df[[weight]])
  } else if (distribution_type == "group") {
    rlang::inform("process for group data not ready yet")
    gini <- NA_real_
  } else {
    msg <- "Wrong `distribution_type`"
    hint <- "Make sure `distribution_type` is either 'micro' or 'group'"
    problem <- paste("your `distribution_type` is", distribution_type)
    rlang::abort(c(
      msg,
      i = hint,
      x = problem
    ),
    class = "wbpip_error"
    )
  }

  # return(gini)
  return(data.table::data.table(gini = gini))
}