hi, I have some session data in a dataframe, where each session is recorded with a start and a stop date. Like this: session_start session_stop =================== 2009-01-03 2009-01-04 2009-01-01 2009-01-05 2009-01-02 2009-01-09 A session is at least one day long. Now I want a dataframe with 'active sessions' per date. Like this: date active_sessions ============= 2009-01-01 1 2009-01-02 2 2009-01-03 3 2009-01-04 3 2009-01-05 2 2009-01-06 1 2009-01-07 1 2009-01-08 1 2009-01-09 1 How do I do that? I've searched the usual sources, but my newbie status and language barrier left me with nothing. So plz, anyone?
Counting session days
3 messages · Stefan Petersson, Gabor Grothendieck, Gustaf Rydevik
Try this:
dateseq <- function(i) seq(DF[i, 1], DF[i, 2], 1) table(as.Date(unlist(lapply(1:nrow(DF), dateseq)), origin = "1970-01-01"))
2009-01-01 2009-01-02 2009-01-03 2009-01-04 2009-01-05 2009-01-06 2009-01-07
1 2 3 3 2 1 1
2009-01-08 2009-01-09
1 1
On Mon, Feb 9, 2009 at 10:57 AM, <stefan.petersson at inizio.se> wrote:
hi, I have some session data in a dataframe, where each session is recorded with a start and a stop date. Like this: session_start session_stop =================== 2009-01-03 2009-01-04 2009-01-01 2009-01-05 2009-01-02 2009-01-09 A session is at least one day long. Now I want a dataframe with 'active sessions' per date. Like this: date active_sessions ============= 2009-01-01 1 2009-01-02 2 2009-01-03 3 2009-01-04 3 2009-01-05 2 2009-01-06 1 2009-01-07 1 2009-01-08 1 2009-01-09 1 How do I do that? I've searched the usual sources, but my newbie status and language barrier left me with nothing. So plz, anyone?
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On Mon, Feb 9, 2009 at 4:57 PM, <stefan.petersson at inizio.se> wrote:
hi, I have some session data in a dataframe, where each session is recorded with a start and a stop date. Like this: session_start session_stop =================== 2009-01-03 2009-01-04 2009-01-01 2009-01-05 2009-01-02 2009-01-09 A session is at least one day long. Now I want a dataframe with 'active sessions' per date. Like this: date active_sessions ============= 2009-01-01 1 2009-01-02 2 2009-01-03 3 2009-01-04 3 2009-01-05 2 2009-01-06 1 2009-01-07 1 2009-01-08 1 2009-01-09 1 How do I do that? I've searched the usual sources, but my newbie status and language barrier left me with nothing. So plz, anyone?
Hej Stefan, The following should do. It's a bit convoluted though, so someone else might be able to come up with a better solution.
test
start stop 1 2009-01-03 2009-01-04 2 2009-01-01 2009-01-05 3 2009-01-02 2009-01-09 activeDaysPerSession<-apply(test,MARGIN=1,FUN=function(x) seq(from=as.Date(x["start"]), to=as.Date(x["stop"]),by=1 ) ) ActiveDays<-as.Date(unlist(activeDaysPerSession)) as.data.frame(table(ActiveDays)) Regards, Gustaf
Gustaf Rydevik, M.Sci. tel: +46(0)703 051 451 address:Essingetorget 40,112 66 Stockholm, SE skype:gustaf_rydevik