[R] apply() question

[Patrick Burns]

do.call("rbind", your.list)

Patrick Burns

Burns Statistics
patrick at burns-stat.com
+44 (0)20 8525 0696
http://www.burns-stat.com
(home of S Poetry and "A Guide for the Unwilling S User")

Robin Hankin wrote:

> Hi
>
> I have a function that returns an array with four columns but the
> number of rows differs with the calling argument.  I want to use
> something like sapply() to rbind() the outputs together.
>
> Following toy example illustrates my problem:
>
> f  <- function(i) {
>   options(warn= -1)
>   r <- ceiling(sqrt(i))
>   return(matrix(1:3,r,4))
> }
>
> Thus sapply(1:5,f) is a list with five elements.
>
> R> (a <- sapply(1:5,f))
> [[1]]
>      [,1] [,2] [,3] [,4]
> [1,]    1    2    3    1
>
> #{...DELETED...}
>
> [[5]]
>      [,1] [,2] [,3] [,4]
> [1,]    1    1    1    1
> [2,]    2    2    2    2
> [3,]    3    3    3    3
>
> R>
>
> what I want is the equivalent of
>
> R> rbind(a[[1]],a[[2]],a[[3]],a[[4]],a[[5]])
>
> but with an arbitrary upper limit and without any loops.  Anyone?
>
>
> Obligatory attempt:
> R> string<-paste("jj<-rbind(a[[1]] ",paste(",a[[",2:5,"]]",collapse=" 
> "),")")
> R> eval(parse(text=string))
>
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