I am trying to build a single vector that holds elements of several vectors with different lengths. As an example, let’s consider three vectors:

x <- rnorm(5,0,1)
y <- rnorm(2,0,1)
z <- rnorm(3,0,1)

To get this done in a handy, I used the sapply function as follows

set.seed(123)
vec <- sapply(c(5,2,3), function(n) rnorm(n,0,1))

but this lists them as separate vectors

[[1]]
[1] -0.5605 -0.2302  1.5587  0.0705  0.1293

[[2]]
[1] 1.715 0.461

[[3]]
[1] -1.265 -0.687 -0.446

Is there away of improving this code or applying some other functions to have the three vectors as a single vector so that it appears as

[1] -0.5605 -0.2302  1.5587  0.0705  0.1293 1.715 0.461 -1.265 -0.687 -0.446

Any help is well appreciated.

>Solution :

We can use unlist to convert a list into a vector.

unlist(sapply(c(5,2,3), function(n) rnorm(n,0,1)))

[1]  0.2185724 -1.4715697 -1.5881170 -0.5791368 -1.1028307
[6] -0.5208913 -0.7065582  0.1414712  0.6883996  0.3030542