CODEWITHSUNDEEP
r
Aravind Raj Reddy
Aravind Raj Reddy

Reputation: 59

Generate rank by group

How to create rank in data frame based on marks but rank should be separated based on gender:

Sl.no   Name    Gender  Marks   Rank
1   aa  Male    77  3
2   bb  Female  80  2
3   cc  Male    74  4
4   dd  Female  72  5
5   ee  Male    87  1
6   ff  Female  80  3
7   gg  Male    72  5
8   hh  Female  84  1
9   ii  Male    82  2
10  jj  Female  79  4

Upvotes: 1

Views: 92

Answers (1)

akrun
akrun

Reputation: 887048

We can use a group by operation

library(data.table)
setDT(df1)[order(-Marks), Rank := seq_len(.N), by = Gender]
df1
#    Sl.no Name Gender Marks Rank
#1:     1   aa   Male    77    3
#2:     2   bb Female    80    2
#3:     3   cc   Male    74    4
#4:     4   dd Female    72    5
#5:     5   ee   Male    87    1
#6:     6   ff Female    80    3
#7:     7   gg   Male    72    5
#8:     8   hh Female    84    1
#9:     9   ii   Male    82    2
#10:   10   jj Female    79    4

Or with dplyr

library(dplyr)
df1 %>% 
    group_by(Gender) %>%
    arrange(Gender, desc(Marks)) %>%
    mutate(Rank = row_number())

Upvotes: 2

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