R help - May 1999 - sum(is.na(c(...)) -> negative number; bug or feature?

As I understand it, sum() treats a logical vectors as 1's and 0's, so
that
> is.logical(c(FALSE,TRUE,FALSE))
[1] TRUE
> sum(c(FALSE,TRUE,FALSE))
[1] 1

However,  summing the results of an is.na() yields a
negative number.  Eg
> is.na(c(1,NA,3))
[1] FALSE  TRUE FALSE
> is.logical(is.na(c(1,NA,3)))
[1] TRUE
> sum(is.na(c(1,NA,3)))
[1] -1

(This is from R Version 0.64.0, under Redhat Linux 5.2 (compiled from
scratch
 using egcs-g77-1.0.3a-14, although I can't imagine that's relevant).

Is this a bug, or is there something about sum() that I'm missing?

Thanks

--------------------
Barnet Wagman

wagman at enteract.com
773-645-8369

1361 N. Hoyne
Chicago, IL 60622
---------------------



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Barnet Wagman <wagman at enteract.com> writes:
> > sum(is.na(c(1,NA,3)))
> [1] -1
> 
> (This is from R Version 0.64.0, under Redhat Linux 5.2 (compiled from
> scratch
>  using egcs-g77-1.0.3a-14, although I can't imagine that's
relevant).
> 
> Is this a bug, or is there something about sum() that I'm missing?
Bug in is.na(), fixed in 0.64.1.

Apparently, POSIX only specifies that isnan() returns nonzero on NaN's
and RH5.2 took that literally...

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