Create a dataframe from two vectors of unequal length in R

I have two vectors of unequal length. Let’s call them group1 and group2.

group1 <- c(1,2,3)
group2 <- c(6,7,8,9,10)

I want to create a dataframe like:

…So on

I know how to do it if the length of the vectors is the same: just create a tibble and then gather it.
But what to do in this case?

>Solution :

You may try

group1 <- 1:3
group2 <- 6:10
n <- length(group2) - length(group1)
group1 <- c(group1, rep(NA, n))

tibble(group1,group2) %>%
  rownames_to_column("idx") %>%
  gather(group1,group2, key = 'key', value = 'value') %>%
  mutate(idx = as.numeric(idx)) %>%
  mutate(idx = ifelse(key == 'group1', floor(idx/2), floor((idx-1)/2))) %>%
  arrange(idx, key) %>%
  na.omit %>% select(-idx)


  key    value
  <chr>  <int>
1 group1     1
2 group2     6
3 group2     7
4 group1     2
5 group1     3
6 group2     8
7 group2     9
8 group2    10