Replace value in column if another column is <0

March 10, 2023

I have a dataframe and then have ranked the values across each row. I’m looking to update this so that if the value in the original data frame is <=0 the rank value become 0, otherwise keep the rank number.

So with the example data below rank rows 1 & 2 would become:

0 1 0
0 0 1

example data:

df <- data.frame(score_1 = floor(runif(10, min=-10, max=10)),
                 score_2 = floor(runif(10, min=-10, max=10)),
                 score_3 = floor(runif(10, min=-10, max=10))) 

   score_1 score_2 score_3
1       -3       4      -7
2        0     -10       5
3       -2      -8      -8
4       -6      -6       3
5       -2      -6      -7
6       -1      -4      -4
7      -10      -7       2
8        0       7       3
9      -10       6      -1
10       9      -5      -3

rank <- df %>%
    rowwise() %>%
do(data.frame(t(rank(-unlist(.)))))

rank
 score_1 score_2 score_3
  
 1     2       1       3
 2     2       3       1  
 3     1       2.5     2.5
 4     2.5     2.5     1
 5     1       2       3
 6     1       2.5     2.5
 7     3       2       1
 8     3       1       2
 9     3       1       2
10     1       3       2

>Solution :

Since the two dataframes are of same dimensions you can do a direct replacement.

rank[df <= 0] <- 0
rank

#   score_1 score_2 score_3
#     <dbl>   <dbl>   <dbl>
# 1       0       1       0
# 2       0       0       1
# 3       0       0       0
# 4       0       0       1
# 5       0       0       0
# 6       0       0       0
# 7       0       0       1
# 8       0       1       2
# 9       0       1       0
#10       1       0       0