CODEWITHSUNDEEP
rdplyr
NewBee
NewBee

Reputation: 1040

multiply set of columns by one column in data frame in R

I know that I can use mutate across to multiply one columns by other specific columns like this:

mtcars %>% mutate(across(disp),.*carb)

In my data, both my variables are numeric:

> str(trad_clean_weighted$Q10_1)
 num [1:1024] NA NA 0 1 NA 0 0 NA 1 1 ...
 - attr(*, "label")= chr "Q10_1.Dance assessed and reported via report card"
> str(trad_clean_weighted$wgt_part1B)
 num [1:1024] 9.73 1.9 3.09 3.1 21.42 ...

However, I get this error when I try to multiply the columns:

my_data %>%
mutate(across(Q10_1),.*wgt_part1B)

Error: Problem with `mutate()` input `..2`.
x non-numeric argument to binary operator
i Input `..2` is `. * wgt_part1B`.

I don't understand why I am getting this error when both variables are numeric! :(

Any thoughts?

Upvotes: 1

Views: 1639

Answers (1)

akrun
akrun

Reputation: 887881

It is because the across got closed after the column name.

my_data %>%
        mutate(across(Q10_1, ~ . * wgt_part1B))

If there are vector of column names, specify those within the across

nm1 <- c('Q10_1', 'Q10_2')
my_data %>%
   mutate(across(all_of(nm1), ~ .* wgt_part1B))

FOr a single column, we don't need to use across

 my_data %>%
      mutate(Q10_1 = Q10_1 * wgt_part1B)

Upvotes: 4

Related Questions