using nested functions in do.call in R

Question

I have a data.frame named df with one column named Text, consisting of some sentences, and I want to add a new column named Length equal to number of words in the Text column. So, my data.frame looks like this:

      Text
1. First sentence.
2. Second sentence that is a bit longer.
3. Third.
4. Fourth one is the longest one with 9 words.

And the desired data.frame should look like this:

      Text                                  Length
1. First sentence.                              2
2. Second sentence that is a bit longer.        7
3. Third.                                       1
4. Fourth one is the longest one with 9 words.  9

These are my tries:

df$Length <- length(do.call(strsplit(., " ")[[1]], as.list(df$Text)))

and

df$Length <- do.call(length(strsplit(., " ")[[1]]), as.list(df$Text))

Would you please help me understanding what should I do?

`df$length <- lengths(strsplit(as.character(df$Text), "\\s+"))` — Ronak Shah, Mar 24 '20 at 10:29
Thanks @AllanCameron, it gave me: Error in strsplit(df$Text, " ") : non-character argument — Mehdi Abbassi, Mar 24 '20 at 10:33
Then you need to convert to a character first, as Ronak Shah demonstrates — Allan Cameron, Mar 24 '20 at 10:34

Florian · Answer 1 · 2020-03-24T10:40:47.787

2

You could also user the purrr-package:

df %>%
 dplyr::mutate(Length = purrr::map_dbl(Text, ~ length(unlist(stringr::str_split(as.character(.), " ")))))

edited Mar 24 '20 at 10:40

answered Mar 24 '20 at 10:27

Florian

1,248
7
21

Thanks @Florian, it gave me: Error in strsplit(., " ") : non-character argument – Mehdi Abbassi Mar 24 '20 at 10:37
Yes, not it works. I just need to assign it to my data.frame (by adding -> df at the end of the code). Thanks @Florian) – Mehdi Abbassi Mar 24 '20 at 10:48

using nested functions in do.call in R

1 Answers1