CODEWITHSUNDEEP
r
afshin
afshin

Reputation:

Generating n samples using a vector

How can i generate 1000 samples with size 8 from a vector containing 20 elements in R. How can i make a single sample a thousand? please help

Upvotes: 0

Views: 266

Answers (2)

Marcin
Marcin

Reputation: 8064

I think using *apply family is better than using a for loop as R is vectorized.

Below is a code that even work on multicore

X=1:20    
# on linux

library(parallel)
library(magrittr)
mclapply(rep(list(X), 1000), sample, 8, replace = TRUE, prob = NULL) %>%
    simplify2array
# on windows
    cl <- makeCluster(detectCores()) # type = "MPI" / type = "PSOCK"
parLapply(cl, rep(list(X), 1000), sample, 8, replace = TRUE, prob = NULL) %>%
   simplify2array
stopCluster(cl)

Upvotes: 0

Minaj
Minaj

Reputation: 175

If X is the vector containing your 20 elements, the you can use:

sample(X, 8, replace = TRUE, prob = NULL)

Loop this statement 1000 times as below:

Results <- matrix(, nrow = 1000, ncol = 8)
X=1:20
for (i in 1:1000){
  Results[i, ]<-sample(X,8,replace=TRUE,prob=NULL)
}

Each row in the matrix called Sample should now represent each of your 1000 samples.

Upvotes: 2

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