R中的仿真

Question

I need to simulate 100 datasets of n=100. I am trying something like:

x1 = NULL 
for (i in 1:100){
set.seed(i)
x1[i] <- sample(1:4, 100, replace=TRUE)
}

But I keep getting errors saying: In x1[i] <- sample(1:4, 100, replace = TRUE) : number of items to replace is not a multiple of replacement length

I am stumped. Any help would be appreciated. Thanks!

Answer 1

You can also use the "replicate" function like this:

x1 <- replicate(100, sample(1:4,100,replace=T))
split(x1, col(x1))

If you are interested, there's an excellent ebook called "R Fundamentals & Graphics" for beginners in R.

Answer 2

All you need to do is change x1[i] to x1[[i]]

Paul