[R] Discretizing data rows into regular intervals

[Linh Tran]

Hi guys,

I'd like to thank you ahead of time for any help that you can offer me.
I'm kind of stuck trying to do this.

I have a data frame with dates and values (note: only two columns shown):

head(test)
        date     value         stop
1     01/02/05     100     12/01/07
2     07/16/05     200     12/01/07
3     12/20/05     150     12/01/07
4     04/01/06     250     12/01/07
5     10/01/06      10     12/01/07

What I need to do is create regularly spaced 3-month intervals (starting
with the first observed date) with values that are closest to but recorded
after the date created. I would stop at the stop date. So the result would
look like:

      new_date   value
1     01/02/05     100
2     04/02/05     100
3     07/02/05     100
4     10/02/05     200
5     01/02/06     150
6     04/02/06     250
7     07/02/06     250
8     10/02/06      10
9     01/02/07      10
etc
etc
etc   10/02/07     ---  ## Final obs since next one would be 1/2/08 (after
stop date)

Again, I would be extremely grateful for any help.

Thanks,

-linh