[R] Quick recode of -999 to NA in R

[Gabor Grothendieck]

On Wed, Mar 30, 2011 at 11:51 AM, peter dalgaard <pdalgd at gmail.com> wrote:
>
> On Mar 30, 2011, at 16:05 , Christopher Desjardins wrote:
>
>>>
>>> dat0 <- read.table('tim1.dat', na = -999)
>>>
>>
>> Ah ... yes. I knew that but clearly didn't at the time of my question or
>> script writing.
>> Thanks,
>> Chris
>
> Depending on where your data came from, you could get caught by the fact that the above is really ...na.strings="-999"... and that is not going to work if the actual code is (say) -999.00.
>
> Another straightforward option is dat0[dat0 == -999] <- NA

That's a good point about -999.00.  If we knew all the variations in
the input then a workaround for that would be to cover all of them:

read.table("myfile", ...whatever...,   na.strings = c("-999",
"-999.0", "-999.00"))

-- 
Statistics & Software Consulting
GKX Group, GKX Associates Inc.
tel: 1-877-GKX-GROUP
email: ggrothendieck at gmail.com