nmode's Git Repositories - Rnaught/blob - R/WP_known.R

   1 #' WP method background function WP_known
   2 #'
   3 #' This is a background/internal function called by \code{WP}.  It computes the maximum likelihood estimator of R0 assuming that the serial distribution is known and finite discrete.
   4 #'
   5 #' @param NT vector of case counts
   6 #' @param p discretized version of the serial distribution
   7 #' @return The function returns \code{Rhat}, the maximum likelihood estimator of R0.
   8 #' @export
   9 #
  10
  11 WP_known                <-      function(NT, p){
  12
  13         k               <-      length(p)
  14         TT              <-      length(NT)-1
  15         mu_t    <-      rep(0, TT)
  16         for(i in 1:TT){
  17                 Nt              <-      NT[i:max(1,i-k+1)]
  18 #               print(Nt)
  19 #               print(p[1:min(k,i)])
  20                 mu_t[i] <-      sum(p[1:min(k,i)]*Nt)
  21         }
  22         Rhat    <-      sum(NT[-1])/sum(mu_t)
  23         return(list(Rhat=Rhat))
  24
  25 }
  26
  27