R/rpredEG_v0.R

In vgharris3/predictiveInference: Predictive Inference Tools for Researchers

#' The Exponential-Gamma Predictive Distribution
#'
#' @param S desired random sample size
#' @param y list of observed and censored survival times (y1,...,yN), yi ~ exp(theta), theta ~ Gamma(dt, gm)
#' @param d < N s.t. (yd+1, ..., yN) are censored
#' @param dt Gamma shape parameter for distribution of theta
#' @param gm Gamma rate parameter for distribution of theta
#'
#' @return random sample of size S from the Exponential-Gamma predictive probability distribution
#' @export
#'
#' @examples 1
rpredEG_v0 = function(S, y, d, dt, gm){

  a = d + dt
  b = gm + sum(y)
  # theta = stats::rgamma(1,shape=a,rate=b)
  theta = stats::rgamma(S,shape=a,rate=b)

  return(stats::rexp(S,theta))
}