R/saspoint5_distribution.R

In boostmath: 'R' Bindings for the 'Boost' Math Functions

#' @title S\eqn{\alpha}S Point5 Distribution Functions
#' @name saspoint5_distribution
#' @description Functions to compute the probability density function, cumulative distribution function, and quantile function for the S\eqn{\alpha}S Point5 distribution.
#' @param x quantile
#' @param location location parameter (default is 0)
#' @param scale scale parameter (default is 1)
#' @param p probability (0 <= p <= 1)
#' @return A single numeric value with the computed probability density, log-probability density, cumulative distribution, log-cumulative distribution, or quantile depending on the function called.
#' @seealso [Boost Documentation](https://www.boost.org/doc/libs/latest/libs/math/doc/html/math_toolkit/dist_ref/dists/saspoint5_dist.html) for more details on the mathematical background.
#' @examples
#' # SaS Point5 distribution with location 0 and scale 1
#' dist <- saspoint5_distribution(0, 1)
#' # Apply generic functions
#' cdf(dist, 0.5)
#' logcdf(dist, 0.5)
#' pdf(dist, 0.5)
#' logpdf(dist, 0.5)
#' hazard(dist, 0.5)
#' chf(dist, 0.5)
#' median(dist)
#' mode(dist)
#' range(dist)
#' quantile(dist, 0.2)
#' support(dist)
#'
#' # Convenience functions
#' saspoint5_pdf(3)
#' saspoint5_lpdf(3)
#' saspoint5_cdf(3)
#' saspoint5_lcdf(3)
#' saspoint5_quantile(0.5)
NULL

#' @rdname saspoint5_distribution
#' @export
saspoint5_distribution <- function(location = 0, scale = 1) {
  structure(
    list(
      extptr = .Call(`saspoint5_init_`, location, scale),
      location = location,
      scale = scale
    ),
    class = c("saspoint5_distribution", "boost_distribution")
  )
}

#' @rdname saspoint5_distribution
#' @export
saspoint5_pdf <- function(x, location = 0, scale = 1) {
  pdf(saspoint5_distribution(location, scale), x)
}

#' @rdname saspoint5_distribution
#' @export
saspoint5_lpdf <- function(x, location = 0, scale = 1) {
  logpdf(saspoint5_distribution(location, scale), x)
}

#' @rdname saspoint5_distribution
#' @export
saspoint5_cdf <- function(x, location = 0, scale = 1) {
  cdf(saspoint5_distribution(location, scale), x)
}

#' @rdname saspoint5_distribution
#' @export
saspoint5_lcdf <- function(x, location = 0, scale = 1) {
  logcdf(saspoint5_distribution(location, scale), x)
}

#' @rdname saspoint5_distribution
#' @export
saspoint5_quantile <- function(p, location = 0, scale = 1) {
  quantile(saspoint5_distribution(location, scale), p)
}