Think I have an easy question but I was not able to find my mistake so far. I want to create a single elimination tournament with 32 participants. To do so I created 4 groups with 8 Players and now a want to build the matchups with a for loop and store them into a list, but its not working as I want :(
>groups
A B C D
1 Player1 Player9 Player17 Player25
2 Player2 Player10 Player18 Player26
3 Player3 Player11 Player19 Player27
4 Player4 Player12 Player20 Player28
5 Player5 Player13 Player21 Player29
6 Player6 Player14 Player22 Player30
7 Player7 Player15 Player23 Player31
8 Player8 Player16 Player24 Player32
now I want to store them as pairs in their groups to have an easy access to calculate winning props later on. Should look like this for the first Group A
>teams.group.A <- matrix(groups$A,nrow = 2,ncol = 4)
>teams.group.A
[,1] [,2] [,3] [,4]
[1,] "Player1" "Player3" "Player5" "Player7"
[2,] "Player2" "Player4" "Player6" "Player8"
my idea for the loop was:
groupnames <- colnames(groups)
mylist <- list()
for(i in groupnames){
mylist[[i]] <- matrix(groups$i,nrow = 2,ncol = 4)
}
mylist
I get the error, that "data" must be a vector type?
Thx, if you can help me here!
Assuming your groups variable is a dataframe, you can easily use lapply and you'll get a nice named list as a result:
# generate data
players <- paste0('Player',1:32)
grps <- data.frame(A=players[1:8],B=players[9:16],C=players[17:24],D=players[25:32])
#smoother version as suggested by P Lapointe:
mylist <- lapply(grps,matrix,nrow=2)
# more verbose
# mylist <- lapply(grps,function(x) matrix(x,ncol = 4))
# output
> mylist
$A
[,1] [,2] [,3] [,4]
[1,] "Player1" "Player3" "Player5" "Player7"
[2,] "Player2" "Player4" "Player6" "Player8"
$B
[,1] [,2] [,3] [,4]
[1,] "Player9" "Player11" "Player13" "Player15"
[2,] "Player10" "Player12" "Player14" "Player16"
$C
[,1] [,2] [,3] [,4]
[1,] "Player17" "Player19" "Player21" "Player23"
[2,] "Player18" "Player20" "Player22" "Player24"
$D
[,1] [,2] [,3] [,4]
[1,] "Player25" "Player27" "Player29" "Player31"
[2,] "Player26" "Player28" "Player30" "Player32"
To bring it back into a single dataframe, you can use do.call(cbind,mylist):
> do.call(cbind,mylist)
[,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10] [,11]
[1,] "Player1" "Player3" "Player5" "Player7" "Player9" "Player11" "Player13" "Player15" "Player17" "Player19" "Player21"
[2,] "Player2" "Player4" "Player6" "Player8" "Player10" "Player12" "Player14" "Player16" "Player18" "Player20" "Player22"
[,12] [,13] [,14] [,15] [,16]
[1,] "Player23" "Player25" "Player27" "Player29" "Player31"
[2,] "Player24" "Player26" "Player28" "Player30" "Player32"