R help - Mar 2012 - list of matrices

Hello dear R-users,

I am currently trying to fill some datasatructure (array, list, hash...) 
with matrices that are calculated by a function and do vary in size:

mylist = list()
for(i in 1:n)
     mylist[i] = function(...) # returns a matrix

print(mylist[1]) # prints only the first element of the matrix


How can I store and afterwards access the matrices that are calculated 
by my function?

Any help would be greatly appreciated!

Best Wishes
David

Use
mylist[[i]] = function(...)

mylist[i] and mylist[[i]] are two different things.

On Wed, Mar 21, 2012 at 11:08 AM, David Zastrau <davidz at tzi.de>
wrote:
> Hello dear R-users,
>
> I am currently trying to fill some datasatructure (array, list, hash...)
> with matrices that are calculated by a function and do vary in size:
>
> mylist = list()
> for(i in 1:n)
> ? ?mylist[i] = function(...) # returns a matrix
>
> print(mylist[1]) # prints only the first element of the matrix
>
>
> How can I store and afterwards access the matrices that are calculated by
my
> function?
>
> Any help would be greatly appreciated!
>
> Best Wishes
> David
>
-- 
Sarah Goslee
http://www.functionaldiversity.org

You probably want

mylist[[i]] = function(...)

in your loop.

Similarly, when you want them again later, you need to use double
square brackets.

I once heard a useful metaphor for understanding the difference
between [ and [[ when it comes to lists.

If x (a list) is a train, then x[2] is the second car of that train,
while x[[2]] are the contents of that second car.

That's why things like, x[1:3] are well defined (the sublist
containing elements 1 through 3) while x[[1:3]] are not.

Hope this helps,
Michael

On Wed, Mar 21, 2012 at 11:08 AM, David Zastrau <davidz at tzi.de>
wrote:
> Hello dear R-users,
>
> I am currently trying to fill some datasatructure (array, list, hash...)
> with matrices that are calculated by a function and do vary in size:
>
> mylist = list()
> for(i in 1:n)
> ? ?mylist[i] = function(...) # returns a matrix
>
> print(mylist[1]) # prints only the first element of the matrix
>
>
> How can I store and afterwards access the matrices that are calculated by
my
> function?
>
> Any help would be greatly appreciated!
>
> Best Wishes
> David
>
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