R/visualize.gamma.R

In coatless/visualize: Graph Probability Distributions with User Supplied Parameters and Statistics

#' Visualize Gamma Distribution
#' 
#' Generates a plot of the Gamma distribution with user specified parameters.
#' 
#' 
#' @param stat a statistic to obtain the probability from. When using the
#' "bounded" condition, you must supply the parameter as `stat =
#' c(lower_bound, upper_bound)`. Otherwise, a simple `stat =
#' desired_point` will suffice.
#' @param alpha `alpha` is considered to be *shape* by R's
#' implementation of the gamma distribution. `alpha` must be greater than
#' 0.
#' @param theta `theta` is considered to be *rate* by R's
#' implementation of the gamma distribution. `theta` must be greater than
#' 0.
#' @param section Select how you want the statistic(s) evaluated via
#' `section=` either `"lower"`,`"bounded"`, `"upper"`,
#' or`"tails"`.
#' @author James Balamuta
#' @export
#' @seealso [visualize.it()], [dgamma()].
#' @keywords continuous-distribution
#' @examples
#' 
#' # Evaluate lower tail.
#' visualize.gamma(stat = 1, alpha = 3, theta = 1, section = "lower") 
#' 
#' # Evaluate bounded section.
#' visualize.gamma(stat = c(0.75,1), alpha = 3, theta = 1, section = "bounded") 
#' 
#' # Evaluate upper tail.
#' visualize.gamma(stat = 1, alpha = 3, theta = 1, section = "upper") 
#' 
#' 
visualize.gamma <-
function(stat = 1, alpha = 1, theta = 1, section = "lower") {
  visualize.it('gamma', stat = stat, list(alpha = alpha, theta = theta), section = section)
}