R/rfystar.R

In BNPdensity: Ferguson-Klass Type Algorithm for Posterior Normalized Random Measures

#' Conditional posterior distribution of the distinct Ystar
#'
#' This function evaluates the ratio of conditional posterior distributions of
#' the distinct latents Ystar.
#'
#' For internal use.
#'
#' @keywords internal
#' @examples
#'
#' ## The function is currently defined as
#' function(v, v2, x, distr.k, sigma.k, distr.p0, mu.p0, sigma.p0) {
#'   alpha <- p0(v, distr = distr.p0, mu = mu.p0, sigma = sigma.p0) /
#'     p0(v2, distr = distr.p0, mu = mu.p0, sigma = sigma.p0)
#'   Prod <- 1
#'   for (i in seq(length(x))) {
#'     fac <- dk(x[i], distr = distr.k, mu = v, sigma = sigma.k) /
#'       dk(x[i], distr = distr.k, mu = v2, sigma = sigma.k)
#'     Prod <- Prod * fac
#'   }
#'   f <- alpha * Prod
#'   return(f)
#' }
rfystar <-
  function(v, v2, x, distr.k, sigma.k, distr.p0, mu.p0, sigma.p0) {
    alpha <- p0(v, distr = distr.p0, mu = mu.p0, sigma = sigma.p0) / p0(v2,
      distr = distr.p0, mu = mu.p0, sigma = sigma.p0
    )
    Prod <- 1
    for (i in seq(length(x))) {
      fac <- dk(x[i], distr = distr.k, mu = v, sigma = sigma.k) / dk(x[i],
        distr = distr.k, mu = v2, sigma = sigma.k
      )
      Prod <- Prod * fac
    }
    f <- alpha * Prod
    return(f)
  }