Generate matrix with value flags
- by pagid
I do have a solution for the following problem but it's quite ugly and it can most likely be done in a much shorter way. Would be great to get your help.
My input looks like this:
C1 C2
A B
B D
D C
A D
and my output should look like this:
A B C D
1 1 0 0
0 1 0 1
0 0 1 1
1 0 0 1
My current solution is:
index <- unique(unlist(input[,1:2]))
output <- matrix(0,nrows=dim(input),ncols=length(index))
for(i in 1:dim(input)) {
output[i, input[i,]$C1] <- 1
output[i, input[i,]$C2] <- 1
}
Of course 4-5 lines is actually fine - but even as an R beginner this doesn't feel right to use a for loop. Besides that my actual data has much more than two columns, therefore this doesn't look nice in the end. How would I do that in a smarter way?
Cheers
