# genss: generate SS for model and error from repeated simulations
genss <- function(mu=c(1,2,3),n=4,sigma=1,trial=50)
{
   param_cbind(mu,sigma,n)
   warning(paste(trial,"trials with",sum(param[,3]),"variates",
      "will take time!")
   gennorm <- function(x)
   {
      y <- rnorm(x[3],x[1],x[2])
      c(mean(y),var(y),x[3])
   }
   ss <- matrix(0,trial,2)
   dimnames(ss) <- list(NULL,c("SSmodel","SSerror"))
   for (i in 1:trial)
   {
      stats <- apply(param,1,gennorm)
      grmean <- sum(stats[3,] * stats[1,]) / sum(stats[3,])
      ss[i,"SSmodel"] <- sum(stats[3,] * (stats[1,] - grmean) ^ 2)
      ss[i,"SSerror"] <- sum((stats[3,]-1) * stats[2,])
   }
   ss
}