[R] all combinations with replacement not ordered

2013-11-07 Thread Konstantin Tretiakov
Hello! I need to obtain all possible combinations with replacement when order is not important. E.g. I have a population x{1,2,3}. So I can get (choose(3+3-1,3)=) 10 combinations from this population with 'size=3'. How can I get a list of all that combinations? I have tried 'expand.grid()' and

Re: [R] all combinations with replacement not ordered

2013-11-07 Thread William Dunlap
, November 07, 2013 5:38 AM To: r-help@r-project.org Subject: [R] all combinations with replacement not ordered Hello! I need to obtain all possible combinations with replacement when order is not important. E.g. I have a population x{1,2,3}. So I can get (choose(3+3-1,3)=) 10 combinations

Re: [R] all combinations with replacement not ordered

2013-11-07 Thread Ted Harding
On 07-Nov-2013 13:38:29 Konstantin Tretiakov wrote: Hello! I need to obtain all possible combinations with replacement when order is not important. E.g. I have a population x{1,2,3}. So I can get (choose(3+3-1,3)=) 10 combinations from this population with 'size=3'. How can I get a list

Re: [R] all combinations with replacement not ordered

2013-11-07 Thread Bert Gunter
Well, you can create the expand.grid data frame programmatically via: u - 1:3 len - length(u) v -do.call(expand.grid, split(rep(u,len),rep(seq_len(len),e=len))) And then you can use unique.array to get the unique rows after the sort: unique(t(apply(v,1,sort))) However, I agree with your

Re: [R] all combinations with replacement not ordered

2013-11-07 Thread Bert Gunter
... and actually, since u can be assumed to be of the form shown, v -do.call(expand.grid, split(rep(u,len),rep(u,e=len))) should do. -- Bert On Thu, Nov 7, 2013 at 10:06 AM, Bert Gunter bgun...@gene.com wrote: Well, you can create the expand.grid data frame programmatically via: u - 1:3