First attempt of .632 bootstrap on mean estimation

632_bootstrap_mean.r

adj_test <- function() {
  a <- rnorm(n=100, mean=50, sd=10)
  b <- rnorm(n=100, mean=60, sd=5)
  c <- rnorm(n=100, mean=65, sd=2)
  abc <- c(a,b,c)
  data <- data.frame(key=c(1:300), vals=abc)
  
  boot_mean <- c()
  boot_mean_adj <- c()
  for(i in 1:2000) {
    boot_index <- sample(nrow(data), replace = TRUE)
    boot_data <- data[boot_index,]
    boot_index_missing <- setdiff((1:nrow(data)), unique(boot_index))
    boot_data_missing <- data[boot_index_missing,]
    boot_mean[i] <- mean(boot_data$vals)
    boot_mean_adj[i] <- 0.632*mean(boot_data$vals) + 0.368*mean(boot_data_missing$vals)
  }
  
 return(data.frame(data_mean=mean(data$vals), bootstrap_mean=mean(boot_mean), bootstrap632_mean=mean(boot_mean_adj)))
}


results <- adj_test()
for (i in 1:29) {
  res <- adj_test()
  results <- rbind(results, res)
}