[R] how do I extract all possible combinations of rows from a column

[arun]

Hi,
May be this helps:
library(gtools) 

as.data.frame(t(combinations(5,3,1:5)))
#  V1 V2 V3 V4 V5 V6 V7 V8 V9 V10
#1  1  1  1  1  1  1  2  2  2   3
#2  2  2  2  3  3  4  3  3  4   4
#3  3  4  5  4  5  5  4  5  5   5
A.K.



For a column of data, I need to extract all possible unique 
combinations of 3 rows and combine the results into a data frame (as 
columns). So, for example, if I had a column called "test" that had five rows (the contents of which were the numbers 1:5) all possible 
combinations of 3 rows would be 
1,2,3 
1,2,4 
1,2,5 
1,3,4 
1,3,5 
1,4,5 
2,3,4 
2,4,5 
2,4,5 
3,4,5 

So for this example, R would extract all the combinations shown, and I would get a data frame that looked like this 
1     1     1     1     1     1     2     2     2      3       
2     2     2     3     3     4     3     3     4      4   
3     4     5     4     5     5     4     5     5      5     

Note: I am not considering rearrangements of the same three rows
 to be unique. In other words, the combinations 123, 132, 213, 231, 312,
 321 are all the same as far as I am concerned. If it is not possible to
 do it that way, it will still be helpful, but not quite as helpful. 
Thanks for the help!