selections of data by one variable
Tu Yu-Kang wrote:
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$b==17] and R will give me
f
a b 7 7 17 However, if now I want to select a subgroup according to b==e<-c(13,15,17), then the same syntx doesn't work.
Which language is this??? To summarize, all the code you specified is: a<-c(1:10) & b<-c(11:20) f<-d[d$b==17] b==e<-c(13,15,17) In R, each line for itself is syntacically completely incorrect (even if you say something would work, which is definitely not the case)! "PLEASE do read the posting guide!" I guess you want something like d <- data.frame(a = 1:10, b = 11:20) subset(d, b == 17) e <- c(13, 15, 17) subset(d, b %in% e) Uwe Ligges
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
______________________________________________ R-help at stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html