R help - Apr 2012 - A kind of set operation in R

I have an ordered "set" of numbers, represented by a vector, say

  > X <- c(10:13, 17,18)
  > X
  [1] 10 11 12 13 17 18

then I have a "sub-set" of X, say

  > Y <- c(11,12,17,18)

Is there a simple way in R to have a logical vector (parallel to X) indicating 
what elements of X are in Y, i.e.,

  > Inclusion
  [1] FALSE TRUE TRUE FALSE TRUE TRUE

I'm trying to avoid looping over both vectors to produce the tests. Do you
have
any comments on this?

Thanks,

--Sergio.

At least two ways
> (!is.na(match(X, Y)))
[1] FALSE  TRUE  TRUE FALSE  TRUE  TRUE
> X %in% Y
[1] FALSE  TRUE  TRUE FALSE  TRUE  TRUE
>
On Thu, Apr 5, 2012 at 3:32 PM, Julio Sergio <juliosergio@gmail.com>
wrote:
> I have an ordered "set" of numbers, represented by a vector, say
>
>  > X <- c(10:13, 17,18)
>  > X
>  [1] 10 11 12 13 17 18
>
> then I have a "sub-set" of X, say
>
>  > Y <- c(11,12,17,18)
>
> Is there a simple way in R to have a logical vector (parallel to X)
> indicating
> what elements of X are in Y, i.e.,
>
>  > Inclusion
>  [1] FALSE TRUE TRUE FALSE TRUE TRUE
>
> I'm trying to avoid looping over both vectors to produce the tests. Do
you
> have
> any comments on this?
>
> Thanks,
>
> --Sergio.
>
> ______________________________________________
> 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<http://www.r-project.org/posting-guide.html>
> and provide commented, minimal, self-contained, reproducible code.
>
	[[alternative HTML version deleted]]

Richard M. Heiberger <rmh <at> temple.edu> writes:
> 
> At least two ways
> 
> > (!is.na(match(X, Y)))
> [1] FALSE  TRUE  TRUE FALSE  TRUE  TRUE
> > X %in% Y
> [1] FALSE  TRUE  TRUE FALSE  TRUE  TRUE
Thanks Richard!

--Sergio.

On 05-04-2012, at 21:32, Julio Sergio wrote:
> I have an ordered "set" of numbers, represented by a vector, say
> 
>> X <- c(10:13, 17,18)
>> X
>  [1] 10 11 12 13 17 18
> 
> then I have a "sub-set" of X, say
> 
>> Y <- c(11,12,17,18)
> 
> Is there a simple way in R to have a logical vector (parallel to X)
indicating
> what elements of X are in Y, i.e.,
> 
>> Inclusion
>  [1] FALSE TRUE TRUE FALSE TRUE TRUE
> 
> I'm trying to avoid looping over both vectors to produce the tests. Do
you have
> any comments on this?
Try

X %in% Y

You could also have a look at match

Berend

Berend Hasselman <bhh <at> xs4all.nl> writes:
 
> Try
> 
> X %in% Y
> 
> You could also have a look at match
> 
> Berend
> 
> 
Thanks Berend!

--Sergio.