[R] subset without removing NAs

[David Winsemius]

On Apr 28, 2011, at 3:53 PM, Benjamin Caldwell wrote:

> Hi folks,
>
> I'm dealing with a dataset with a lot of NAs, and want to use subset  
> on the
> data without removing the NAs from the the dataframe; e.g.
>
> rws50 <- subset(rw.fire.RW,shigo.av<50)
>
> This removes instances with NA for the value in addition to anything  
> <50.
> Any suggestions much appreciated.

If you use "[" instead the NA's will come though:

rw.fire.RW[ shigo.av<50, ]

In fact I generally wrap my logicals in which to avoid such  
(mis?)behavior. but you appear to approve of it.

==
David Winsemius, MD
West Hartford, CT