[R] Length of vector without NA's

[Joshua Wiley]

Hi Ralf,

The usual way (as others have shown you), takes advantage of the fact
that the logical values TRUE and FALSE are counted as 1 and 0,
respectively.  is.na() returns TRUE if the value is NA, so to find how
many are not NA, the result is reversed using ' ! '.  Similar logic
can be used to find how many meet any logical condition (e.g.,
sum(1:10 < 5)   ).

Cheers,

Josh

On Thu, Sep 23, 2010 at 8:08 AM, Ralf B <ralf.bierig at gmail.com> wrote:
> Hi,
>
> this following code:
>
> x<-c(1,2,NA)
> length(x)
>
> returns 3, correctly counting numbers as well as NA's. How can I
> exclude NA's from this count?
>
> Ralf
>
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-- 
Joshua Wiley
Ph.D. Student, Health Psychology
University of California, Los Angeles
http://www.joshuawiley.com/