[R] Applying 'cbind/rbind' among different list object

[jim holtman]

will this do it for you:

> lapply(seq(length(list1)), function(i)rbind(list1[[i]], list2[[i]]))
[[1]]
     [,1] [,2] [,3] [,4] [,5]
[1,]    1    6   11   16   21
[2,]    2    7   12   17   22
[3,]    3    8   13   18   23
[4,]    4    9   14   19   24
[5,]    5   10   15   20   25
[6,]   10   11   12   13   14

[[2]]
     [,1] [,2] [,3] [,4] [,5]
[1,]    2    7   12   17   22
[2,]    3    8   13   18   23
[3,]    4    9   14   19   24
[4,]    5   10   15   20   25
[5,]    6   11   16   21   26
[6,]   11   12   13   14   15


On Sun, Feb 6, 2011 at 1:32 PM, B. Jonathan B. Jonathan
<bkheijonathan at gmail.com> wrote:
> Hi, I am wondering whether we can apply 'cbind/rbind' on many **equivalent**
> list objects. For example please consider following:
>
>> list1 <- list2 <- vector("list", length=2); names(list1) <- names(list2)
> <- c("a", "b")
>> list1[[1]] <- matrix(1:25, 5)
>> list1[[2]] <- matrix(2:26, 5)
>> list2[[1]] <- 10:14
>> list2[[2]] <- 11:15
>> list1
> $a
>     [,1] [,2] [,3] [,4] [,5]
> [1,]    1    6   11   16   21
> [2,]    2    7   12   17   22
> [3,]    3    8   13   18   23
> [4,]    4    9   14   19   24
> [5,]    5   10   15   20   25
> $b
>     [,1] [,2] [,3] [,4] [,5]
> [1,]    2    7   12   17   22
> [2,]    3    8   13   18   23
> [3,]    4    9   14   19   24
> [4,]    5   10   15   20   25
> [5,]    6   11   16   21   26
>> list2
> $a
> [1] 10 11 12 13 14
> $b
> [1] 11 12 13 14 15
>
> Here I want to "rbind" these 2 list-s according to "a" and "b" i.e. I want
> to get another list of length 2 where each element will be matrix with (6x5)
> dimension. How can I do that?
>
> Thanks for your time
>
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>
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-- 
Jim Holtman
Data Munger Guru

What is the problem that you are trying to solve?