In R, you can do it using the `rep`command:

    tab <- data.frame(value=c(1,2,3), freq=c(3,2,5))
    vec <- rep(tab$value, tab$freq)

This gives following result:

    > tab
      value freq
    1     1    3
    2     2    2
    3     3    5
    > vec
     [1] 1 1 1 2 2 3 3 3 3 3

For details, see the help file for the `rep`command by typing `?rep`.