# [R] List to Array

Dimitris Rizopoulos dimitris.rizopoulos at med.kuleuven.be
Wed Apr 5 16:13:45 CEST 2006

```then maybe this is what you're looking for:

L <- list(matrix(rnorm(6), nrow = 3), matrix(rnorm(6), nrow = 3))
################
L
array(unlist(L), dim = c(nrow(L[[1]]), ncol(L[[1]]), length(L)))

Best,
Dimitris

----
Dimitris Rizopoulos
Ph.D. Student
Biostatistical Centre
School of Public Health
Catholic University of Leuven

Address: Kapucijnenvoer 35, Leuven, Belgium
Tel: +32/(0)16/336899
Fax: +32/(0)16/337015
Web: http://www.med.kuleuven.be/biostat/
http://www.student.kuleuven.be/~m0390867/dimitris.htm

----- Original Message -----
From: "Werner Wernersen" <pensterfuzzer at yahoo.de>
To: "Gabor Grothendieck" <ggrothendieck at gmail.com>
Cc: <r-help at stat.math.ethz.ch>
Sent: Wednesday, April 05, 2006 3:55 PM
Subject: Re: [R] List to Array

> Oh yes, I should give an example:
>
> m <- matrix(1:6,nrow=3)
> L <- list(m,m)
>
> Output of L:
> [[1]]
>     [,1] [,2]
> [1,]    1    4
> [2,]    2    5
> [3,]    3    6
>
> [[2]]
>     [,1] [,2]
> [1,]    1    4
> [2,]    2    5
> [3,]    3    6
>
>
> I would like to transform L to and array looking like
> this:
> , , 1
>
>     [,1] [,2]
> [1,]    1    4
> [2,]    2    5
> [3,]    3    6
>
> , , 2
>
>     [,1] [,2]
> [1,]    1    4
> [2,]    2    5
> [3,]    3    6
>
>
>> Please supply some test data and the expected answer
>> since its not clear what is desired here.
>>
>> On 4/5/06, Werner Wernersen <pensterfuzzer at yahoo.de>
>> wrote:
>> > Hi,
>> >
>> > this is probably the easiest thing to do but I
>> manage
>> > not finding the answer:
>> > I have a list with matrices of exact same format
>> and
>> > headers. Now I would like to transform the list
>> into
>> > an normal array. What is the proper way to do
>> this?
>> > as.array changes the entire format and right now I
>> > only found the method of creating a new array,
>> going
>> > through the entire list and copy the matrix in
>> each
>> > list element to the new array.
>> >
>> > Thanks a million for your help!
>> >  Werner
>> >
>> > ______________________________________________
>> > R-help at stat.math.ethz.ch mailing list
>> > https://stat.ethz.ch/mailman/listinfo/r-help
>> > PLEASE do read the posting guide!
>> http://www.R-project.org/posting-guide.html
>> >
>>
>
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