The rule is not important to me. I'm selecting a sample
that must have one important feature: the same number of
obs from x and from y with the same k1.
Thanks
Cecília
Em Fri, 20 Aug 2010 08:28:24 -0400
David Winsemius <dwinsem...@comcast.net> escreveu:
On Aug 20, 2010, at 6:44 AM, Cecilia Carmo wrote:
Hi everyone!
I'm matching two samples to create one sample that have
pairs of observations equal for the k1 variable. Merge()
doesn't
work because I dont't want to recycle the values.
When there is more than one possible match in either y
or x to a possible match on k1 in the othr set of
values, is there some rule that lets you determine which
one should be chosen. Your offered solution suggests
that you think the order in the original data.frams is a
proper rule, but why should we believe that rule is
anything other than convenience?
--
David.
x <- data.frame(k1=c(1,1,2,3,3,5),
k2=c(20,21,22,23,24,25))
x
y <- data.frame(k1=c(1,1,2,2,3,4,5,5),
k2=c(10,11,12,13,14,15,16,17))
y
merge(x,y,by="k1")
k1 k2.x k2.y
1 1 20 10
2 1 20 11
3 1 21 10
4 1 21 11
5 2 22 12
6 2 22 13
7 3 23 14
8 3 24 14
9 5 25 16
10 5 25 17
I have a final dataframe with 10 rows, but I want it
with 5 rows,
like this:
k1 k2.x k2.y
1 1 20 10
2 1 21 11
3 2 22 12
4 3 23 14
5 5 25 16
Thanks for any help.
Cecília Carmo
(Universidade de Aveiro)
David Winsemius, MD
West Hartford, CT
______________________________________________
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.
