如何在 R 中获取数字向量的元素，并创建一个包含 seq 从 1:(每个元素）的新向量

Question

Let's say I have a vector called input <- c(8,5,2) . I want to create a new vector in which is essentially c(1:8, 1:5, 1:2) . I can do it in the following ugly way:

input <- c(8,5,2);
newvec <- c();
for(num in input) newvec <- append(newvec, 1:num);
newvec

But I feel like it should be doable in one-line, and I'm probably just oblivious to a simple solution.

Answer 1

An easier R option is sequence

sequence(input)
#[1] 1 2 3 4 5 6 7 8 1 2 3 4 5 1 2

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Or use lapply and unlist

unlist(lapply(input, seq))