Spend a little time with aggregate() ?aggregate
------------------------------------- David L Carlson Department of Anthropology Texas A&M University College Station, TX 77840-4352 -----Original Message----- From: R-help [mailto:r-help-boun...@r-project.org] On Behalf Of najuzz Sent: Monday, December 22, 2014 7:45 AM To: r-help@r-project.org Subject: [R] number of individuals where X=0 during all periods (longitudinal data) #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.