[R] when to use `which'?

[Joshua Wiley]

On Tue, Jul 12, 2011 at 1:17 PM, Sam Steingold <sds at gnu.org> wrote:
> when do I need to use which()?

See ?which

For examples, try:

example(which)

>> a <- c(1,2,3,4,5,6)
>> a
> [1] 1 2 3 4 5 6
>> a[a==4]
> [1] 4
>> a[which(a==4)]
> [1] 4
>> which(a==4)
> [1] 4
>> a[which(a>2)]
> [1] 3 4 5 6
>> a[a>2]
> [1] 3 4 5 6
>>
>
> seems unnecessary...

Yes, it can be used as a redudant wrapper as you have demonstrated in
your examples.  In those cases, it is most certainly unnecessary.

>
> --
> Sam Steingold (http://sds.podval.org/) on CentOS release 5.6 (Final) X 11.0.60900031
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-- 
Joshua Wiley
Ph.D. Student, Health Psychology
University of California, Los Angeles
https://joshuawiley.com/