[R] selections of data by one variable
Tu Yu-Kang
yukangtu at hotmail.com
Wed May 4 13:14:10 CEST 2005
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
More information about the R-help
mailing list