[R] random sample from list

[Rui Barradas]

Hello,

>
> #Here is how I have tried to sample but it is not sampling from the right
> part of the list
> 
> bg<- z_nonna[sample(1:length(z_nonna), 5000, replace=FALSE)]
> 

You are sampling from the length of z_nonna, with no guarantee that they are
indices to unique list elements.

Try this.

# First, create some fake data.
n <- 1000
z <- list()
set.seed(1234)
for(i in 1:n) z[[i]] <- sample(letters, 2)

# Now sample some unique elements from it.
iz <- which(!duplicated(z))
iz <- sample(iz, 100) # sample from the non-duplicate indices.
z[iz]

Hope this helps,

Rui Barradas


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