[R] Condition %in%
David Winsemius
dwinsemius at comcast.net
Mon Sep 13 23:54:46 CEST 2010
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
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