dplyr::mutate to add multiple values

Question

There are a couple of issues about this on the dplyr Github repo already, and at least one related SO question, but none of them quite covers my question -- I think.

Answer 1

Yet another option could be to use the purrr::map family of functions.

If you replace rbind with dplyr::bind_rows in the get_binCI function:

library(tidyverse)

dd <- data.frame(x = c(3, 4), n = c(10, 11))
get_binCI <- function(x, n) {
  bind_rows(setNames(c(binom.test(x, n)$conf.int), c("lwr", "upr")))
}

You can use purrr::map2 with tidyr::unnest:

dd %>% mutate(result = map2(x, n, get_binCI)) %>% unnest()

#>   x  n        lwr       upr
#> 1 3 10 0.06673951 0.6524529
#> 2 4 11 0.10926344 0.6920953

Or purrr::map2_dfr with dplyr::bind_cols:

dd %>% bind_cols(map2_dfr(.$x, .$n, get_binCI))

#>   x  n        lwr       upr
#> 1 3 10 0.06673951 0.6524529
#> 2 4 11 0.10926344 0.6920953