[R] changing the number of elements in a list

09wkj Bill.K.Jannen at williams.edu
Wed Jun 9 15:59:35 CEST 2010


I might give this a try as well:

my.list <- replicate(3, matrix(0, ncol=3, nrow=3), simplify=FALSE)

----
args(replicate)
function (n, expr, simplify = TRUE) 

> replicate(3, matrix(0, ncol=3, nrow=3), simplify=FALSE)
[[1]]
     [,1] [,2] [,3]
[1,]    0    0    0
[2,]    0    0    0
[3,]    0    0    0

[[2]]
     [,1] [,2] [,3]
[1,]    0    0    0
[2,]    0    0    0
[3,]    0    0    0

[[3]]
     [,1] [,2] [,3]
[1,]    0    0    0
[2,]    0    0    0
[3,]    0    0    0

> is.list(replicate(3, matrix(0, ncol=3, nrow=3), simplify=FALSE))
[1] TRUE
----

Bill

On Jun 9, 2010, at 9:54 AM, Ivan Calandra wrote:

> Hi,
> 
> What about:
> my.list <- vector(mode="list", length=number_of_matrices)
> ?
> 
> HTH,
> Ivan
> 
> Le 6/9/2010 15:46, Luis Borda de Agua a écrit :
>> I would like to have a list where each element is a matrix, for example:
>> 
>> my.list<- list(matrix(0, ncol=3, nrow=3),
>>                        matrix(0, ncol=3, nrow=3),
>>                        matrix(0, ncol=3, nrow=3))
>> 
>> The problem is, I would like to be able to change automatically the number of elements in the list (not only three as in the above example).
>> 
>> That is, the instruction creating the list would be a part of a function that has an inputing parameter stating how many elements (matrices) the list has.
>> 
>> I have tried several things, but none worked.
>> However, this seems to be a rather simple problem.
>> All help is welcome!
>> 
>> LBA
>> 
>> ______________________________________________
>> 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.
>> 
>>   
> 
> -- 
> Ivan CALANDRA
> PhD Student
> University of Hamburg
> Biozentrum Grindel und Zoologisches Museum
> Abt. Säugetiere
> Martin-Luther-King-Platz 3
> D-20146 Hamburg, GERMANY
> +49(0)40 42838 6231
> ivan.calandra at uni-hamburg.de
> 
> **********
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> http://webapp5.rrz.uni-hamburg.de/mammals/eng/mitarbeiter.php
> 
> ______________________________________________
> R-help at r-project.org mailing list
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> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
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