I am resending this, as I believe it has not arrived on the mailing
list when I first emailed.
I have a set of labels arranged along a timeframe in a. Each label has
a timestamp and marks a state until the next label. The dataframe a
contains 5 such timestamps and 5 associated labels. This means, on a
continious scale between 1-100, there are 5 markers. E.g. 'abc' marks
the timestampls between 10 and 19, 'def' marks the timestamps between
20 and 32, and so on.
a <- data.frame(timestamp=c(3,5,8),
mylabel=c("abc","def","ghi"))
b <- data.frame(timestamp=c(1:10))
I would like to assign these labels as an extra collumn 'label' to the
data.frame b which currently only consists of a the timestamp. The
output would then look like this:
timestamp label
1 1 NA
2 2 NA
3 3 "abc"
4 4 "abc"
5 5 "def"
6 6 "def"
7 7 "def"
8 8 "ghi"
9 9 "ghi"
10 10 "ghi"
What is the simplest way to assign these labels based on timestamps to
get this output. The real dataset is several millions of rows...
Thanks,
Ralf