R help - Jan 2007 - Working with a set of matrices

Hi,

I have a set of matrices (MAT.1, MAT.2, ...) and I'd like to perform the
same operation on each of them (for simplicity, say . I'm writing a function
for this so that it can be repeated for different sets with different numbers of
matrices. The matrices have the same number of columns, but do not have the same
number of rows.

My thought is to loop thru the set. but I'm not sure how to set the loop up
so that the matrix number changes for each cycle. I have tried paste, but that
leaves quotation marks around the matrix name (e.g., "MAT.1", and I
need just MAT.1), or at least the way I'm using paste..

Any thoughts?  If there is a better way than the loop, then I'm of course
open to that.

Thanks in advance.


 
____________________________________________________________________________________
No need to miss a message. Get email on-the-go 


	[[alternative HTML version deleted]]

Dear M(?),

you could pack your matrices into a list or an environment and then
iterate through that, either using "for" and subset operator
"[[" or
using the lapply / eapply functions.

And instead of looping it is sometimes more elegant to put what you want 
to do with each of your matrices into a function and then repeatedly 
call the function.

Also have a look at "get" for accessing objects e.g. in the global
workspace by their name.

  Best wishes
    Wolfgang

------------------------------------------------------------------
Wolfgang Huber  EBI/EMBL  Cambridge UK  http://www.ebi.ac.uk/huber



M Jones wrote:
> Hi,
> 
> I have a set of matrices (MAT.1, MAT.2, ...) and I'd like to perform
the same operation on each of them (for simplicity, say . I'm writing a
function for this so that it can be repeated for different sets with different
numbers of matrices. The matrices have the same number of columns, but do not
have the same number of rows.
> 
> My thought is to loop thru the set. but I'm not sure how to set the
loop up so that the matrix number changes for each cycle. I have tried paste,
but that leaves quotation marks around the matrix name (e.g., "MAT.1",
and I need just MAT.1), or at least the way I'm using paste..
> 
> Any thoughts?  If there is a better way than the loop, then I'm of
course open to that.
> 
> Thanks in advance.
>