Thank You Profs. Dalgaard and Barradas for the code, both codes worked perfectly for the data and I am going to use it in my big data set. Thanks once again.
On Thu, Feb 6, 2020 at 2:02 AM peter dalgaard <pda...@gmail.com> wrote: > There is also > > > with(daT, tapply(as.character(ObsDate), list(id, ObsSite), > function(x)format(list(x)))) > site1 site4 site5 site7 > id1 NA NA NA "06/13/13" > id2 NA NA NA "07/03/14, 05/17/14" > id4 NA "05/08/14" NA NA > id5 NA NA "06/13/14" NA > id6 "05/30/14, 06/28/13" NA NA NA > id7 NA NA "06/25/13" NA > > ...with the added bonus that if you leave out the format() business, you > get a data structure that doesn't print as nicely, but can be used for > further computations: > > > with(daT, tapply(as.character(ObsDate), list(id, ObsSite), list, > simplify=FALSE)) > site1 site4 site5 site7 > id1 NULL NULL NULL List,1 > id2 NULL NULL NULL List,1 > id4 NULL List,1 NULL NULL > id5 NULL NULL List,1 NULL > id6 List,1 NULL NULL NULL > id7 NULL NULL List,1 NULL > > M <- with(daT, tapply(as.character(ObsDate), list(id, ObsSite), list, > simplify=FALSE)) > > M[["id2", "site7"]] > [[1]] > [1] "07/03/14" "05/17/14" > > -pd > > > On 6 Feb 2020, at 01:37 , Marna Wagley <marna.wag...@gmail.com> wrote: > > > > daT<-structure(list(id = structure(c(1L, 2L, 2L, 3L, 4L, 5L, 5L, 6L > > ), .Label = c("id1", "id2", "id4", "id5", "id6", "id7"), class = > "factor"), > > ObsSite = structure(c(4L, 4L, 4L, 2L, 3L, 1L, 1L, 3L), .Label = > > c("site1", > > "site4", "site5", "site7"), class = "factor"), ObsDate = > > structure(c(4L, > > 8L, 2L, 1L, 5L, 3L, 7L, 6L), .Label = c("05/08/14", "05/17/14", > > "05/30/14", "06/13/13", "06/13/14", "06/25/13", "06/28/13", > > "07/03/14"), class = "factor")), .Names = c("id", "ObsSite", > > "ObsDate"), class = "data.frame", row.names = c(NA, -8L)) > > daT > > daT$date <- mdy(daT$ObsDate) > > -- > Peter Dalgaard, Professor, > Center for Statistics, Copenhagen Business School > Solbjerg Plads 3, 2000 Frederiksberg, Denmark > Phone: (+45)38153501 > Office: A 4.23 > Email: pd....@cbs.dk Priv: pda...@gmail.com > > > > > > > > > > [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.