How to move every other row to a new column in R

Question

I have a data frame that is supposed to show the winners of a tournament and their opponents. Currently the loser is in every other row. So, row 1 is the winner, row 2 is the loser, row 3 is the winner, row 4 is the loser, and so on.

I want the winner and their opponent to be next to each other so that it's easier to see who competed against who. The tricky part is keeping the gym, names, and competitor number for each person together in the same row.

How do I move every other row to a new column so that the winner and their opponent are in the same row?

y = read.csv('https://raw.githubusercontent.com/bandcar/Examples/main/y.csv')

# FAILED ATTEMPT
library(data.table)
z=dcast(setDT(y)[, grp := gl(.N, 2, .N)], grp ~ rowid(grp),
        value.var = setdiff(names(y), 'grp'))[, grp := NULL][]

Note that both photos are different data sets

What my df currently looks like:

Similar to what I want it to look like:

Answer 1

Using dplyr you could do:

library(dplyr)

read.csv('https://raw.githubusercontent.com/bandcar/Examples/main/y.csv') %>%
  group_by(fight, date) %>%
  summarise(division = first(division),
            competitor_1 = first(competitor),
            name_1 = first(name),
            competitor_2 = last(competitor),
            name_2 = last(name))
#> `summarise()` has grouped output by 'fight'. You can override using the
#> `.groups` argument.
#> # A tibble: 61 x 7
#> # Groups:   fight [26]
#>    fight    date                  division competitor_1 name_1    compe~1 name_2
#>    <chr>    <chr>                 <chr>           <int> <chr>       <int> <chr> 
#>  1 BYE      BYE                   Master 2            1 Rafael M~       1 Rafae~
#>  2 FIGHT 19 Thu 09/01 at 12:14 PM Master 2            2 Piter Fr~      63 Alan ~
#>  3 FIGHT 20 Thu 09/01 at 01:01 PM Master 2           16 Marques ~      55 Diego~
#>  4 FIGHT 20 Thu 09/01 at 12:13 PM Master 2           28 Kenned D~      44 Verge~
#>  5 FIGHT 22 Thu 09/01 at 12:27 PM Master 2            4 Marcus V~      52 Kian ~
#>  6 FIGHT 23 Thu 09/01 at 12:33 PM Master 2           30 Adam Col~      46 Steph~
#>  7 FIGHT 23 Thu 09/01 at 12:54 PM Master 2           31 Namrod B~      47 Stefa~
#>  8 FIGHT 23 Thu 09/01 at 12:58 PM Master 2           13 David Ch~      53 Joshu~
#>  9 FIGHT 24 Thu 09/01 at 01:08 PM Master 2            3 Sandro G~      56 Carlo~
#> 10 FIGHT 24 Thu 09/01 at 12:35 PM Master 2            8 Rafael R~      60 Andre~
#> # ... with 51 more rows, and abbreviated variable name 1: competitor_2

^{Created on 2022-09-16 with reprex v2.0.2}

Answer 2

There are some problems with your dataset, eg for "FIGHT 22" there are four entries (from your description I expected two entries).

  division gender belt  weight fight    date                  competitor name                   gym                 
  <chr>    <chr>  <chr> <chr>  <chr>    <chr>                      <dbl> <chr>                  <chr>               
1 Master 2 Male   BLACK Middle FIGHT 22 Thu 09/01 at 12:27 PM          4 Marcus V. C. Antelante Ares BJJ            
2 Master 2 Male   BLACK Middle FIGHT 22 Thu 09/01 at 12:27 PM         62 Andrew E. Ganthier     Renzo Gracie Academy
3 Master 2 Male   BLACK Middle FIGHT 22 Thu 09/01 at 12:27 PM         11 Jimmy Dang Khoa Tat    CheckMat            
4 Master 2 Male   BLACK Middle FIGHT 22 Thu 09/01 at 12:27 PM         52 Kian Takumi Kadota     Brasa CTA           

The same problem exists for fights 26 and 35. Assuming these are corrected, and assuming odd rows contain winners and even rows contain losers, the following code should work (using tidyverse):

y %>% 
    mutate(outcome = if_else(row_number() %% 2 == 1, "winner", "loser")) %>%     
    pivot_wider(names_from = outcome, values_from = c(competitor, name, gym)) 

Answer 3

This will get you close to what you want. It adds the winner column. Odd number index is winner and even number index is loser. I removed the BYE week rows for aesthetics. Then we group by the date and fight and keep the desired data from the combined rows and expand the summarised columns to the winner loser information.

library(dplyr)

y %>%
    mutate(
        winner = ifelse((y$X %% 2) == 0,'loser','winner')) %>%
    filter(date != 'BYE') %>%
    group_by(date, fight) %>% 
    summarise(division = first(division),
              belt = first(belt),
              weight = first(weight),
              gender = first(gender),
              winner.rank = first(competitor),
              winner = first(name),
              winner.gym = first(gym),
              opp.rank= last(competitor),
              opponent = last(name),
              opponent.gym = last(gym))