Dear R experts, Suppose I have an data frame likes this:
> example <- data.frame(age=c(1,2,3, 4,5,6), height=c(100,110,120,130,140,150), > disease=c(TRUE, TRUE, TRUE, FALSE, FALSE, FALSE)) > example age height disease 1 1 100 TRUE 2 2 110 TRUE 3 3 120 TRUE 4 4 130 FALSE 5 5 140 FALSE 6 6 150 FALSE Is there anyway to compare the age and height between those with disease=TRUE and disease=FALSE using t.test and extract the p-values quickly? I can do this individually t.test(example$age~example$disease)[3] But when the number of variable grow to something like 200 it is not easy any more. Thanks! Regards, CH -- CH Chan ______________________________________________ R-help@r-project.org mailing list 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.