get column name based on row values matching in DF in R

Question

I have a table like below, would like to crate suggestions based on row value in R studio.

This is what I have -

id	class1	class2	class3	class4	top1	top2	top3
A	0.98	0.48	0.21	0.99	0.99	0.98	0.48
B	0.22	0.31	0.41	0.11	0.41	0.31	0.22
C	0.70	0.81	0.61	0.21	0.81	0.70	0.61

I would like to have names of the column for top1 top2 top3 as well.

id	class1	class2	class3	class4	top1	top2	top3	top1name	top2name	top3name
A	0.98	0.48	0.21	0.99	0.99	0.98	0.48	class4	class1	class2
B	0.22	0.31	0.41	0.11	0.41	0.31	0.22	class3	class2	class1
C	0.70	0.81	0.61	0.21	0.81	0.70	0.61	class2	class1	class3

Sample data:

I have a table like below, would like to crate suggestions based on row value in R studio.

This is what I have :

id	A	B	C	D	E	F	G
A	0.98	0.48	0.21	0.97	0.47	0.20	0.19
B	0.22	0.31	0.41	0.11	0.42	0.32	0.23
C	0.70	0.81	0.61	0.21	0.82	0.71	0.62

I would like to have names of the column for top1 top2 top3 as well.

id	A	B	C	D	E	F	G	top1name	top2name	top3name	top4name	top5name	top6name	top7name
A	0.98	0.48	0.21	0.97	0.47	0.20		A	D	B	E	C	F
B	0.22	0.31	0.41	0.11	0.42	0.32	0.23	E	C	F	B	G	A	D
C	0.70	0.81	0.61	0.21	0.82	0.71	0.62	E	B	F	A	G	C	D

Answer 1

Here is an approach using dplyr::rowwise with a custom function to generate three new columns containing the number of top classes. Ties between values are captured and displayed in ascending order of class names.

library(dplyr)

get_top3_classes <- function(d) {

  r <- rank(-unlist(d), ties.method = "last")
  out <- names(sort(r))[1:3] 
  out <- gsub("class", "", out) # to get column class index
  m <- matrix(out,
              ncol = 3,
              dimnames = list(NULL, paste0("top", 1:3, "class"))
              )
  as_tibble(m)
  
}

dat %>% 
  rowwise() %>% 
  mutate(get_top3_classes(
            across(matches("class"))
            )
         ) %>% 
  glimpse # for printing

#> Rows: 3
#> Columns: 11
#> Rowwise: 
#> $ id        <chr> "A", "B", "C"
#> $ class1    <dbl> 0.98, 0.22, 0.70
#> $ class2    <dbl> 0.48, 0.31, 0.81
#> $ class3    <dbl> 0.21, 0.41, 0.61
#> $ class4    <dbl> 0.99, 0.11, 0.21
#> $ top1      <dbl> 0.99, 0.41, 0.81
#> $ top2      <dbl> 0.98, 0.31, 0.70
#> $ top3      <dbl> 0.48, 0.22, 0.61
#> $ top1class <chr> "4", "3", "2"
#> $ top2class <chr> "1", "2", "1"
#> $ top3class <chr> "2", "1", "3"

# data containing a tie in the first row
dat <- data.frame(
  stringsAsFactors = FALSE,
  id = c("A", "B", "C"),
  class1 = c(0.98, 0.22, 0.7),
  class2 = c(0.48, 0.31, 0.81),
  class3 = c(0.21, 0.41, 0.61),
  class4 = c(0.99, 0.11, 0.21),
  top1 = c(0.99, 0.41, 0.81),
  top2 = c(0.98, 0.31, 0.7),
  top3 = c(0.48, 0.22, 0.61)
)

^{Created on 2021-08-04 by the reprex package (v0.3.0)}

Update:

Here is a solution for the updated question:

library(dplyr)

get_top3_classes <- function(d) {
  
  r <- rank(-unlist(d), ties.method = "last")
  out <- names(sort(r)) 
  out <- gsub("class", "", out) # to get column class index
  m <- matrix(out,
              ncol = length(out),
              dimnames = list(NULL, paste0("top", seq(length(out)), "names"))
  )
  as_tibble(m)
  
}

dat %>% 
  rowwise(id) %>% 
  mutate(get_top3_classes(
    cur_data()
  )
  ) %>% 
  glimpse # for printing

#> Rows: 3
#> Columns: 15
#> Rowwise: id
#> $ id        <chr> "A", "B", "C"
#> $ A         <dbl> 0.98, 0.22, 0.70
#> $ B         <dbl> 0.48, 0.31, 0.81
#> $ C         <dbl> 0.21, 0.41, 0.61
#> $ D         <dbl> 0.97, 0.11, 0.21
#> $ E         <dbl> 0.47, 0.42, 0.82
#> $ F         <dbl> 0.20, 0.32, 0.71
#> $ G         <dbl> 0.19, 0.23, 0.62
#> $ top1names <chr> "A", "E", "E"
#> $ top2names <chr> "D", "C", "B"
#> $ top3names <chr> "B", "F", "F"
#> $ top4names <chr> "E", "B", "A"
#> $ top5names <chr> "C", "G", "G"
#> $ top6names <chr> "F", "A", "C"
#> $ top7names <chr> "G", "D", "D"

# data 
dat <- tibble::tribble(
  ~id,   ~A,   ~B,   ~C,   ~D,   ~E,   ~F,   ~G,
  "A", 0.98, 0.48, 0.21, 0.97, 0.47,  0.2, 0.19,
  "B", 0.22, 0.31, 0.41, 0.11, 0.42, 0.32, 0.23,
  "C",  0.7, 0.81, 0.61, 0.21, 0.82, 0.71, 0.62
)

^{Created on 2021-08-16 by the reprex package (v2.0.1)}