[R] Adding elements in an array where I have missing data.

[John Kane]

--- Berton Gunter <gunter.berton at gene.com> wrote:

> Below.

My "what does it mean" was meant as a joke!  However
your responses + Gabor's have really helped.  I don't
really have the knowledge to understand everything but
I think I am getting a better feel for what is
happening which should translate to other parts of R
as well.  I have also found that I can use something
on faith for a few days and then I suddenly have
enough context to understand what it is doing.

Thanks again.



> 
> > -----Original Message-----
> > From: Gabor Grothendieck
> [mailto:ggrothendieck at gmail.com] 
> > Sent: Tuesday, May 02, 2006 10:42 AM
> > To: Berton Gunter
> > Cc: John Kane; R R-help
> > Subject: Re: [R] Adding elements in an array where
> I have 
> > missing data.
> > 
> > On 5/2/06, Berton Gunter <gunter.berton at gene.com>
> wrote:
> > > >
> > > > Here are a few alternatives:
> > > >
> > > > replace(a, is.na(a), 0) + b
> > > >
> > > > ifelse(is.na(a), 0, a) + b
> > > >
> > > > mapply(sum, a, b, MoreArgs = list(na.rm =
> TRUE))
> > > >
> > >
> > > Well, Gabor, if you want to get fancy...
> > >
> > > evalq({a[is.na(a)]<-0;a})+b
> > >
> > 
> > Note that the evalq can be omitted:
> > 
> >    { a[is.na] <- 0; a } + b
> > 
> 
> No it can't. The idea is **not** to change the
> original a.
> 
> -- Bert
> 
>