> tmp <- split(Test, Test$ID) > > # number of subjects with X=0 (all periods) > x <- lapply(tmp, function(x) all(x$X ==0)) > length(x[unlist(x)]) [1] 2 > > # number of subjects with X=0 (at least three weeks) > x <- lapply(tmp, function(x) sum(x$X==0)>=3) > length(x[unlist(x)]) [1] 1 >
Is this what you are looking for? I hope this helps. Chel Hee Lee On 12/22/2014 7:45 AM, najuzz wrote:
#Hi guys, #I would like to count the number of individuals that receive X=0 troughout their observational period. #example dataset: ID<-c(1,1,1,1,2,2,3,3,3) X<-c(0,1,2,1,0,0,0,0,0) Time<-c(1,2,3,4,1,2,1,2,3) Test<-data.frame(ID,X,Time) # Individuals 2 and 3 have x=0 during all their periods. The count should hence equal to two. I simply have # no clue how R could solve this for me. As an addon, I would also like to know the number of individuals #that report X=0 during all periods plus have at least 3 weeks of observations. The answer would be one in #this sample datset. #Thank you -- View this message in context: http://r.789695.n4.nabble.com/number-of-individuals-where-X-0-during-all-periods-longitudinal-data-tp4701023.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ 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.
______________________________________________ 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.
