Conditionally Select and Convert a Double to a list of Factors

Question

This is a bit of a weird problem, not sure where to start with this. I have a double:

, , s0

            A        B        C
1   0.55417205 -0.0200187 0.2409565
3  -0.56678215 -0.0200187 0.4754662
18  1.37831681 -0.0200187 0.4260734
20  0.55175931 -0.0200187 0.4061181
28 -1.12156686 -0.0200187 0.4702297
30  0.06913091 -0.0200187 0.4188555
47  0.95545025 -0.0200187 0.2715263
50  0.07951062 -0.0200187 0.4648517
52  0.16938094 -0.0200187 0.3918239
68  0.12219372 -0.0200187 0.4339989
70 -0.11545481 -0.0200187 0.6075105
82 -0.36738143 -0.0200187 0.4444718
83 -0.63349441 -0.0200187 0.4593321
89  2.17432660 -0.0200187 0.1025435

and I want to convert this, based on the highest values in each column row, to a list of factors. For example, row "1" would be A because that has the highest value 0.55, row "3" would be C because the highest value is 0.47 etc. The end result would look like:

A C A A...C A
Levels: A B C

I've tried starting with data.frame and data.table::as.data.table and neither really get me anywhere. Any help would be appreciated, thank you!

Answer 1

You may try using reshape2::melt

Data

dummy <- read.table(text = " row_id           A        B        C
1   0.55417205 -0.0200187 0.2409565
3  -0.56678215 -0.0200187 0.4754662
18  1.37831681 -0.0200187 0.4260734
20  0.55175931 -0.0200187 0.4061181
28 -1.12156686 -0.0200187 0.4702297
30  0.06913091 -0.0200187 0.4188555
47  0.95545025 -0.0200187 0.2715263
50  0.07951062 -0.0200187 0.4648517
52  0.16938094 -0.0200187 0.3918239
68  0.12219372 -0.0200187 0.4339989
70 -0.11545481 -0.0200187 0.6075105
82 -0.36738143 -0.0200187 0.4444718
83 -0.63349441 -0.0200187 0.4593321
89  2.17432660 -0.0200187 0.1025435", header = T)

Code

library(dplyr)
library(reshape2)

dummy %>%
  melt(id.vars = "row_id") %>%
  group_by(row_id) %>%
  filter(value == max(value)) %>%
  arrange(row_id) %>%
  pull(variable)

 [1] A C A A C C A C C C C C C A
Levels: A B C