I’m struggling with a seemingly simple task: in df I want to summarise data in words into strings (no problem) and also the respective Durations of these words (problem). My attempt at subsetting Duration on the condition that [!is.na(words)] fails; instead all values in Duration get stringed together:

library(tidyverse)
df %>%
  summarise(
    words = str_c(words[!is.na(words)], collapse = ","),
    words_dur = str_c(Duration[!is.na(words)], collapse = ",")
  )
            words                     words_dur
1 hey,how,are,you 44,150,30,55,77,80,99,100,200

The expected output is this:

            words      words_dur
1 hey,how,are,you    44,55,77,99

Data:

df <- data.frame(
  words = c("hey", NA, NA, "how", "are", NA, "you", NA, NA),
  Duration = c(44, 150, 30, 55, 77, 80, 99, 100, 200)
)