R help - Sep 2010 - Condition %in%

Hi listers,
If I would like to check if a variable contains certain value, I would
write:
if (10 %in% x)
And If I would like to check the opposite, that 10 is not into x. How would
be?
Thanks in advance,
Marcio
-- 
View this message in context:
http://r.789695.n4.nabble.com/Condition-in-tp2538110p2538110.html
Sent from the R help mailing list archive at Nabble.com.

!10 %in% x

(or !(10 %in% x) if you don't believe in R's precedence rules.

 					- Phil Spector
 					 Statistical Computing Facility
 					 Department of Statistics
 					 UC Berkeley
 					 spector at stat.berkeley.edu


On Mon, 13 Sep 2010, Mestat wrote:
>
> Hi listers,
> If I would like to check if a variable contains certain value, I would
> write:
> if (10 %in% x)
> And If I would like to check the opposite, that 10 is not into x. How would
> be?
> Thanks in advance,
> Marcio
> -- 
> View this message in context:
http://r.789695.n4.nabble.com/Condition-in-tp2538110p2538110.html
> Sent from the R help mailing list archive at Nabble.com.
>
> ______________________________________________
> R-help at 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.
>

On Sep 13, 2010, at 5:43 PM, Mestat wrote:
>
> Hi listers,
> If I would like to check if a variable contains certain value, I would
> write:
> if (10 %in% x)
> And If I would like to check the opposite, that 10 is not into x.  
> How would
> be?
Not sure about your terminology, "into x"?.  why wouldn't it be

if (x %in% 10)
  ... oh, I see, it's that single argument to if() thing again.
 > x <- 10
 > y <- c(10,9)

 > if (y %in% x) TRUE
[1] TRUE
Warning message:
In if (y %in% x) TRUE :
   the condition has length > 1 and only the first element will be used

?all
?any

 > if (all(y %in% x)) TRUE else FALSE
[1] FALSE
 > if (all(x %in% y)) TRUE else FALSE
[1] TRUE

 > if (any(x %in% y)) TRUE else FALSE
[1] TRUE
 > if (any(x %in% y)) TRUE else FALSE
[1] TRUE

So decide what you really want to test. If you want to check to see if  
two groups are the same from a set theoretic viewpoint then setdiff()  
could be used.


David Winsemius, MD
West Hartford, CT