CODEWITHSUNDEEP
r
Denis
Denis

Reputation: 315

Identify row with maximal value in each column of the dataframe in r

I have a table like this:

d=structure(list(sample = c("A", "B", "C", "D", "E"), Obs1 = c(10L, 
0L, 11L, 2L, 3L), Obs2 = c(0L, 0L, 2L, 1L, 10L), Obs3 = c(1L, 
1L, 1L, 1L, 10L), Obs4 = c(0L, 11L, 3L, 3L, 3L), Obs5 = c(7L, 
7L, 3L, 3L, 3L)), class = "data.frame", row.names = c(NA, -5L
))

For each column i'd like to find row with maximal value in this column to get in result a table like (for my example):

enter image description here

How can i achieve that in R (preferably in Base library).

Upvotes: 0

Views: 59

Answers (1)

G. Grothendieck
G. Grothendieck

Reputation: 270075

Use apply twice:

data.frame(sample = apply(d[-1], 2, function(x) toString(d[x == max(x), 1])),
           max = apply(d[-1], 2, max))

giving this data.frame:

     sample max
Obs1      C  11
Obs2      E  10
Obs3      E  10
Obs4      B  11
Obs5   A, B   7

Upvotes: 2

Related Questions