#' Returns G_prior matrix for the Emperical Bayes Prior selection method
#' @export

G_prior_EB_selection<-function(O,omega,omega0){
  r=dim(O)[2]
  ordered_chisq=sort(rchisq(r,20,0))
  rnk=rank(c(omega,omega0))
  
  D=diag(ordered_chisq[r-rnk+1])
  G=O%*% D%*%t(O)
  return(G)
}