[R] Use mapply or lapply to a nested list

Jim Lemon drj|m|emon @end|ng |rom gm@||@com
Tue Dec 22 10:07:36 CET 2020

Hi Chao,
I think what you are looking for is the "rapply" function in the base
package. Not sure that it can do exactly what you request but worth a


On Tue, Dec 22, 2020 at 6:36 AM Chao Liu <psychaoliu using gmail.com> wrote:
> I want to apply a sample function to a nested list (I will call this list
> `bb`) and I also have a list of numbers (I will call this list `k`) to be
> supplied in the sample function. I would like each of the numbers in k to
> iterate through all the values of each list in bb. How to do this using
> `mapply` or `lapply`?
> Here are the data:
> k <- list(1,2,4,3) #this is the list of numbers to be supplied in the `
> sample.int` function
> b1 <- list(c(1,2,3),c(2,3,4),c(3,4,5),c(4,5,6)) #The first list of bb
> b2 <- list(c(1,2),c(2,3),c(3,4),c(4,5), c(5,6)) #The second list of bb
> bb <- list(b1,b2) #This is list bb containing b1 and b2 whose values are to
> be iterated through
> ```
> I created this `mapply` function but it didn't get the expected outcome:
> mapply(function(x, y) {
>    x[sample.int(y,y, replace = TRUE)]
> }, bb,k, SIMPLIFY = FALSE)
> This only returns 10 output values but I would like each number of k to
> loop through all values of the two lists in `bb` and so there should be
> 10*2 outputs for the two lists in `bb`. I might be using `mapply` in the
> wrong way and so I would appreciate if anyone can point me to the right
> direction!
> Best,
> Chao
>         [[alternative HTML version deleted]]
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