collapse variables in R if row value is true

Question

I want to collapse some variables into a single variable if the variable value is True

Eg: Data set

A B C D E F
F T F F...
F F T F..
F F F T..
T F F F..
F F F F....

The output I am looking for

New_variable
- B
- C
- D
- A
- .

As you can see if the row value is true I would like to replace it with its corresponding column value.

Thank you,

score 1 · Answer 1 · answered Dec 17 '19 at 16:14

1

We can use max.col to find the column name in each row based on the TRUE value

i1 <- rowSums(df1) == 0
df1$New_variable <- names(df1)[max.col(df1, "first")]
df1$New_variable[i1] <- ""

answered Dec 17 '19 at 16:14

akrun

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score 1 · Answer 2 · answered Dec 17 '19 at 16:19

use any() to identify at least one value in the column is TRUE

df1 <- read.table(text='A B C D E F
           F T F F F F
                  F F T F F F
                  F F F T F F
                  T F F F F F
                  F F F F F F', header = TRUE)

colnames(df1)[ (apply( df1, 2, any)) ]
# [1] "A" "B" "C" "D"

collapse variables in R if row value is true

2 Answers2