[R] is there a way to recursilvely lapply
Prof Brian Ripley
ripley at stats.ox.ac.uk
Thu Dec 11 22:02:30 CET 2008
On Thu, 11 Dec 2008, Whit Armstrong wrote:
> Thanks, Gabor and Prof. Ripley.
> Sorry for the oversight.
> I grepped the lapply help for recursive prior to sending my question.
> why does it appear as "*r*ecursive" in the help file? or is that just
> a formating problem on my machine?
It is marked as bold: I presume you are reading text help?
> On Thu, Dec 11, 2008 at 3:13 PM, Prof Brian Ripley
> <ripley at stats.ox.ac.uk> wrote:
>> On Thu, 11 Dec 2008, Whit Armstrong wrote:
>>> for a simple example:
>>> x <- list()
>>> x[["a"]] <- list(a=c(1,2,3),b=c(3,4,5))
>>> x[["b"]] <- list(a=c(6,7,8),b=c(9,10,11))
>>> this fails w/
>>> Error in FUN(X[[1L]], ...) : invalid 'type' (list) of argument
>>> Just wondering if I have overlooked something obvious.
>> rapply? Which is linked from ?lapply (I just checked). Perhaps
>>> rapply(x, sum)
>> a.a a.b b.a b.b
>> 6 12 21 30
>>> rapply(x, sum, how="list")
>>  6
>>> one can also do:
>>> but that assumes that you already know how many levels you have, and
>>> that all the levels are consistent.
>>> R-help at r-project.org mailing list
>>> PLEASE do read the posting guide
>>> and provide commented, minimal, self-contained, reproducible code.
>> Brian D. Ripley, ripley at stats.ox.ac.uk
>> Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/
>> University of Oxford, Tel: +44 1865 272861 (self)
>> 1 South Parks Road, +44 1865 272866 (PA)
>> Oxford OX1 3TG, UK Fax: +44 1865 272595
Brian D. Ripley, ripley at stats.ox.ac.uk
Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/
University of Oxford, Tel: +44 1865 272861 (self)
1 South Parks Road, +44 1865 272866 (PA)
Oxford OX1 3TG, UK Fax: +44 1865 272595
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