Labelling two separate data frames by row and then merging them into one data frame under the same column but with row labels preserved

Question

I have two data sets, lets call them

A: 1, 3, 5, 6, 3

and

B: 2, 4, 7, 9, 8

Where the numbers in A and B represent time

I want to label all of the numbers in A by row as "positive" and all numbers in B labelled "Negative" by row.

I then want to merge both A and B into a single data frame under one column called "time", but they must keep their row names "Positive"/"Negative" for their corresponding number so I can plot both onto a survival plot

Answer 1

My guess is that you are looking for such a dataframe:

A <- data.frame(time = c(1, 3, 5, 6, 3), status= "positive")
B <- data.frame(time = c(2, 4, 7, 9, 8), status= "negative")

rbind(A, B)

Output:

   time   status
1     1 positive
2     3 positive
3     5 positive
4     6 positive
5     3 positive
6     2 negative
7     4 negative
8     7 negative
9     9 negative
10    8 negative