CODEWITHSUNDEEP
rsample
Rose
Rose

Reputation: 53

How to get different samples based on a sample size

I have a sample like this:

V   echo
A   2
D   4
N   12
P   6
D   4
P   2
N   3
A   1

I want to get three data frame samples (n=20,n=50, n=100), based on this sample with replacement and then I want to calculate the mean and SD for each sample.

Upvotes: 1

Views: 40

Answers (2)

ThomasIsCoding
ThomasIsCoding

Reputation: 101054

Do you mean something like below?

n <- c(20, 50, 100)
lapply(
    n,
    function(k) {
        df[sample(nrow(df), k, replace = TRUE), ]
    }
)

Or, we can use split (probably faster than my previous option)

split(
    df[sample(nrow(df), sum(n), replace = TRUE), ],
    rep(seq_along(n), n)
)

Upvotes: 2

akrun
akrun

Reputation: 886938

Loop over those numbers

sapply(c(20, 50, 100), function(x) {
     x1 <- sample(df1$echo, x, replace = TRUE)
     c(Mean = mean(x1), SD = sd(x1))})

If we want to return 3 dataset samples

lst1 <- lapply(c(20, 50, 100), function(x) {
            i1 <- sample(seq_len(nrow(df1)), x, replace = TRUE)
            df1[i1, , drop = FALSE]
})

Upvotes: 2

Related Questions