[R] storing matrices in a list or vector and preserve dimensions

[Bram Kuijper]

Hi all,

As an R newbie, I wonder how I can store multiple matrices in a list() 
or vector() object without losing their structure. I should be able to 
retrieve the matrix from the list later on.

If I just append() the matrices to a list() object, they automatically 
lose their dimensions, whereas I would like to preserve the dimensions 
of the matrices.

Is there any function in R which allows me to store a _fully preserved_ 
object inside a list() or vector() structure?

thanks in advance,

Bram Kuijper




PS: this is what I do:

# two matrices, which are my objects to be put in the list
my_matrix_object1 <- matrix(data=rep(1,times=9),nrow=3,ncol=3);
my_matrix_object2 <- matrix(data=rep(0,times=9),nrow=3,ncol=3);

my_list <- list()
# note that I explicitly want to append the object to the list
# instead of directly inserting it from the beginning
# (e.g., code to be used in a for-loop)
my_list <- append(my_list,as.matrix(my_matrix_object1));
my_list <- append(my_list,as.matrix(my_matrix_object2));

However, this results in the following list structure...
[[1]]
[1] 1

[[2]]
[1] 1

[[3]]
[1] 1

... etcetera,

whereas I just want to preserve the matrix structure in my list:

my_matrix_object1;
      [,1] [,2] [,3]
[1,]    1    1    1
[2,]    1    1    1
[3,]    1    1    1
,
      [,1] [,2] [,3]
[1,]    0    0    0
[2,]    0    0    0
[3,]    0    0    0

I guess I need a more sophisticated function then append, but I do not 
know which one?