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rmatchcbind

How to add a column with the column-names of the value in the row?

My question may not be so well formulated and sounds complicated. But what I want is very simple. From the given Data frame Df I have made a new Data frame Df1 which contains the max values ​​from each individual column. Now I want to add to my new data frame Df1 a column with the name of each column from which the max value comes.

I have prepared an example for this.

A <- runif(5,min = 0.1, max = 3)
B <- runif(5,min = 0.1, max = 3)
C <- runif(5,min = 0.1, max = 3)
D <- runif(5,min = 0.1, max = 3)
E <- runif(5,min = 0.1, max = 3)
F <- runif(5,min = 0.1, max = 3)

Car <- c("Audi","BMW","Mercedes","Ford","Opel")

Df<-data.frame(Car,A,B,C,D,E,F)

Df1<-Df%>%
  group_by(Car)%>%
  summarize(max.value = max(A,B,C,D,E,F))

Df:

enter image description here

Df1:

enter image description here

What I want:

enter image description here

Solution

  • An option would be

    library(dplyr)
Df %>%
   transmute(Car, max.value = pmax(!!! .[-1]), 
             rowName = names(.)[-1][max.col(.[-1])])