How to Recode Multiple Columns with the Same Conditions?
I Have a Data Set That Has over 260 Columns That Have Character Values That Need to Be Recoded as Numerical Factors. for Example, N=0, Y=1, S=1, O=2, F=99...
I have a data set that has over 260 columns that have character values that need to be recoded as numerical factors. For example, N=0, Y=1, S=1, O=2, F=99. However, apply this to only some columns, not all, so I need to do this by column name. Here is what I have so far:
df <- data.frame(col1 = c("N", "N", "O", "N", "N", "N", "N", "N", "S", "O"),
col2 = c("F", "N", "S", "O", "Y", "Y", "S", "F", "S", "O"),
col3 = c("Y", "O", "Y", "N", "Y", "F", "N", "O", "S", "N"),
col4 = c("S", "S", "O", "O", "Y", "S", "N", "O", "S", "N"),
col5 = c("N", "S", "F", "O", "N", "F", "N", "O", "N", "N"),
col6 = c("O", "N", "S", "N", "N", "N", "N", "F", "N", "O"),
col7 = c("F", "F", "O", "O", "O", "N", "N", "O", "Y", "Y"),
col8 = c("O", "N", "O", "S", "F", "N", "N", "Y", "S", "N"),
col9 = c("N", "O", "O", "Y", "N", "S", "N", "O", "N", "Y"),
col10 = c("N", "N", "S", "F", "N", "N", "F", "Y", "N", "O"))
df %>% mutate_at(.vars = c("col1", "col4", "col9"), funs(ifelse(*** == "N", 0, .)))
The 3 astericks indicate the problem. I have to specify the column name to make the recode. I run into the same problem in base R. Is there a way to do it to tell R that "these columns by name when equal to 'N' make 0".
2 Answers
You could do with across().
df <- df |>
mutate(across(c(col1, col4, col9), ~case_when(.x=="N" ~ 0,
.x %in% c("Y","S") ~ 1,
.x == "O" ~ 2,
.x =="F" ~ 99)))
output
col1 col2 col3 col4 col5 col6 col7 col8 col9 col10
1 0 F Y 1 N O F O 0 N
2 0 N O 1 S N F N 2 N
3 2 S Y 2 F S O O 2 S
4 0 O N 2 O N O S 1 F
5 0 Y Y 1 N N O F 0 N
6 0 Y F 1 F N N N 1 N
7 0 S N 0 N N N N 0 F
8 0 F O 2 O F O Y 2 Y
9 1 S S 1 N N Y S 0 N
10 2 O N 0 N O Y N 1 O
I ended up creating a function with a for-loop, looping through the names of the columns.
Alexander Ross has covered the video game industry for a decade, writing deep dives on game design, esports tournaments, VR developments, and gaming culture.
