Conditional sum with NAs

Question

I have a following dataframe.

id	color	grade
1	green	B
2	red
3		C
4
5	blue	A

I have to add columns named col_scr and grd_scr based on color and grade. Then I have to add those two columns to get a column named final_score. My desired dataframe should look like as follow,

id	color	grade	col_scr	grd_scr	final_score
1	green	B	1	1	3
2	red		3	NA	3
3		C	NA	0	0
4			NA	NA	NA
5	blue	A	2	2	4

My code so far looks like,

df <- df %>%
   mutate(col_scr = case_when(color == 'green' ~ 1,
                              color == 'blue' ~ 2,
                              color == 'red' ~ 3),
          grd_scr = case_when(grade == 'A' ~ 2,
                              grade == 'B' ~ 1,
                              grade == 'C' ~ 0))

How to add my 3rd column final_score into mutate?

Please provide a reproducible data set using `dput`. – Maël Aug 15 '22 at 13:50 — Maël, Aug 15 '22 at 13:50

Maël · Answer 1 · 2022-08-15T14:18:27.437

3

You can use an ifelse condition to sum only if both variable are not NAs, otherwise NA (credits to @Darren Tsai for the if_all part).

df %>% 
  mutate(final_score = ifelse(if_all(col_csr:grd_scr, is.na), 
                              NA, rowSums(across(col_scr:grd_scr), na.rm = T)))

edited Aug 15 '22 at 14:18

answered Aug 15 '22 at 13:50

Maël

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@Maël your code gives 2 for all rows in the final_score column – learner Aug 15 '22 at 14:16
@learner See my edit, it should work fine now. – Maël Aug 15 '22 at 14:19

Conditional sum with NAs

1 Answers1