On May 13, 2010, at 9:55 AM, David Winsemius wrote:
On May 13, 2010, at 9:48 AM, Carrie Li wrote:
Hi, dear R-helpers,
I have a simple question regarding selecting subset of a variable
based on
another variable.
Here is the example:
xx=rnorm(10)
id=sample(1:10, 10)
temp=c(6, 1, 8, 2)
Now, all I want is xx's that their id are 6, 1, 8, 2, instead of the
position.
Any suggestions ?
xx[temp]
I may have jumped the gun, but on reflection I am not sure that your
question was at all clear. Is the first item desired the 6th item of
xx or the xx item referenced by the 6th item of id? You gave a
specification that would not allow any of us to check, since you did
not specify a random seed. We have no way of seeing what either of
your xx or id vectors look like since you did not provide either them
or the desired output. If it were the second specification then
consider this:
> set.seed(123)
> xx=rnorm(10)
> id=sample(1:10, 10)
>
> temp=c(6, 1, 8, 2)
> xx;id
[1] -0.56047565 -0.23017749 1.55870831 0.07050839 0.12928774
1.71506499
[7] 0.46091621 -1.26506123 -0.68685285 -0.44566197
[1] 9 7 6 10 4 8 3 2 1 5
> xx[id[temp]]
[1] -1.2650612 -0.6868529 -0.2301775 0.4609162
--
David.
Thank you all your help !!
Carrie
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______________________________________________
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
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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.
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.
