selections of data by one variable
try this: d <- data.frame(a=1:10, b=11:20) e <- c(13, 15, 17) ############## d. <- subset(d, b %in% e) d. I hope it helps. Best, Dimitris ---- Dimitris Rizopoulos Ph.D. Student Biostatistical Centre School of Public Health Catholic University of Leuven Address: Kapucijnenvoer 35, Leuven, Belgium Tel: +32/16/336899 Fax: +32/16/337015 Web: http://www.med.kuleuven.ac.be/biostat/ http://www.student.kuleuven.ac.be/~m0390867/dimitris.htm ----- Original Message ----- From: "Tu Yu-Kang" <yukangtu at hotmail.com> To: <R-help at stat.math.ethz.ch> Sent: Wednesday, May 04, 2005 1:14 PM Subject: [R] selections of data by one variable
Dear R experts, My problem is as follows: Suppose I have a data frame d comprising two variable a<-c(1:10) & b<-c(11:20). I now want to select a subgroup according the values of b. I know if I just want to select, say, b=17, I can use f<-d[d$b==17] and R will give me
f
a b 7 7 17 However, if now I want to select a subgroup according to b==e<-c(13,15,17), then the same syntx doesn't work. What is the correct way to do it? My data have more than one million subjects, and I want to select part of them according to their id numbers. Your help will be highly appreciated. Best regards, Yu-Kang
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