test <- data.frame(cbind(1:10,11:20))
names(test) <- c("a", "b")
test[test$b == 17,]
test[test$b %in% c(13, 15, 17),]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. > > 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@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 > > ______________________________________________ R-help@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
