[R] selections of data by one variable

From: Tu Yu-Kang <yukangtu_at_hotmail.com>
Date: Wed 04 May 2005 - 21:14:10 EST


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 Received on Wed May 04 22:52:00 2005

This archive was generated by hypermail 2.1.8 : Fri 03 Mar 2006 - 03:31:35 EST