[R] Creating panel data

[Jeff]

   I'm new to R.
   I am trying to create panel data with a slight alteration from a typical
   dataset.
   At  present,  I  have  data  on a few hundred people with the dates of
   occurrences for several events (like marriage and employment). The dates are
   in year/quarter format, so 68.0 equals the 1st quarter of 1968 and 68.25
   equals the 2nd quarter of 1968. If the event never occurred, 0 is recorded
   for the Year Of Occurrence. Somewhat redundantly, I also have separate
   dichotomous  variables indicating whether the event ever occurred (0/1
   format).
   For example:
   x <- data.frame( id = c(1,2), Event1Occur = c(1,0), YearOfOccurEvent1 =
   c(68.25,0), Event2Occur = c(0,1), YearOfOccurEvent2 = c(0,68.5))
   I need to transform that dataframe so that I have a separate row for each
   time period (year/quarter) for each person, with variables for whether the
   event had already occurred during that time period. If the event occurred
   during an earlier time, it is presumed to still be occurring at later times.
   E.g., if the person got married in the first quarter of 1968, they are
   presumed to still be married at all later time periods. I need those time
   periods marked (0/1).
   For example:
   y   <-   data.frame(   id   =   c(   rep  (1,5),  rep  (2,5)),  Year=c
   (68.0,68.25,68.50,68.75,69.0))
   y $ Event1 <- c (0,1,1,1,1,0,0,0,0,0)
   y $ Event2 <- c (0,0,0,0,0,0,0,1,1,1)
   can someone get me started.
   Thanks
   Jeff