[R] applying cbind (or any function) across all components in a list

[David L Carlson]

You don't make it clear if you want the two lists processed in parallel, but
if so, this may be a step toward the function you want:

Combine <- function(l1, l2) {
  pattern <- cbind(c(1, 2, 2, 3), c(1, 1, 2, 2))
  for (i in 1:length(l1)) {
    print((l1[[i]][,pattern[,1]]+l2[[i]][,pattern[,2]])/2)
  }
}
Combine(l1, l2)

This simply prints the results, but you didn't indicate how you wanted the
output organized.

----------------------------------------------
David L Carlson
Associate Professor of Anthropology
Texas A&M University
College Station, TX 77843-4352


> -----Original Message-----
> From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-
> project.org] On Behalf Of Greg Snow
> Sent: Thursday, May 24, 2012 10:17 AM
> To: Hans Thompson
> Cc: r-help at r-project.org
> Subject: Re: [R] applying cbind (or any function) across all components
> in a list
> 
> The "do.call" function may be what you want, but it is not completely
> clear.  If that does not solve your problem then try giving us an
> example of what your list looks like (the dput function can help) and
> what you want your end result to look like.
> 
> On Thu, May 24, 2012 at 5:38 AM, Hans Thompson
> <hans.thompson1 at gmail.com> wrote:
> > The combination of column means in cbind is what I am trying to do.
>  I just
> > don't know how to do it for every component (2 in this case) of the
> list.
> > I've been able to work with R to apply a function across all
> components when
> > there is just one list but I am having trouble working with multiple
> lists
> > at the same time.
> >
> > --
> > View this message in context: http://r.789695.n4.nabble.com/applying-
> cbind-or-any-function-across-all-components-in-a-list-
> tp4631128p4631187.html
> > Sent from the R help mailing list archive at Nabble.com.
> >
> > ______________________________________________
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> > PLEASE do read the posting guide http://www.R-project.org/posting-
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> > and provide commented, minimal, self-contained, reproducible code.
> 
> 
> 
> --
> Gregory (Greg) L. Snow Ph.D.
> 538280 at gmail.com
> 
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-
> guide.html
> and provide commented, minimal, self-contained, reproducible code.