Matrix of vectors in R

Question

Is it possible to create matrix of vectors in R? I mean the elements of this matrix must be vectors. For example mat[1,3] == c(6,8,9)

i must create 40x40 matrix and i need to fill it manually.

Answer 1

This is not a matrix but an array:

myarray <- array(1:24, c(2,4,3))
myarray[1,3,]
#[1]  5 13 21

Answer 2

Well, you can add dimensions to a list, so that it resembles a matrix where the elements can be anything you want, including vectors of different length. For example:

foo <- as.list(numeric(2^2))
dim(foo) <- c(2,2)

# Assignment per element:
foo[[1,1]] <- 1:4
foo[[1,2]] <- 1:10
foo[[2,1]] <- "foo"
foo[[2,2]] <- list(foo)

Gives you a weird looking object:

> foo
     [,1]      [,2]      
[1,] Integer,4 Integer,10
[2,] "foo"     List,1    

Where each element basically is a vector. Still, this is hardly ever the best way of doing this. If the vectors are the same length an array as described by Roland is much more appropriate.