[R] Create unique sets of 3 from a vector of IDs?

2008-12-02 Thread philozine
Dear all: This is one of those should be easy problems that I'm having great difficulty solving. I have a vector containing ID codes, and I need to generate a 3-column matrix that contains all possible combinations of three. For example, my ID vector looks like this: A B C D E I need to

Re: [R] Create unique sets of 3 from a vector of IDs?

2008-12-02 Thread Dylan Beaudette
On Tue, Dec 2, 2008 at 7:42 PM, philozine [EMAIL PROTECTED] wrote: Dear all: This is one of those should be easy problems that I'm having great difficulty solving. I have a vector containing ID codes, and I need to generate a 3-column matrix that contains all possible combinations of three.

Re: [R] Create unique sets of 3 from a vector of IDs?

2008-12-02 Thread G. Jay Kerns
Dear Brandon, On Tue, Dec 2, 2008 at 10:46 PM, Dylan Beaudette [EMAIL PROTECTED] wrote: On Tue, Dec 2, 2008 at 7:42 PM, philozine [EMAIL PROTECTED] wrote: Dear all: This is one of those should be easy problems that I'm having great difficulty solving. I have a vector containing ID codes,

Re: [R] Create unique sets of 3 from a vector of IDs?

2008-12-02 Thread Kingsford Jones
However, I believe Brandon was trying to get the permutations of size 3, rather than combinations. Dylan provided a solution including repeats. Here's one without: library(gtools) permutations(5, 3, LETTERS[1:5]) [,1] [,2] [,3] [1,] A B C [2,] A B D [3,] A B E [4,] A C B

Re: [R] Create unique sets of 3 from a vector of IDs?

2008-12-02 Thread G. Jay Kerns
Dear Kingsford, You are quite right, my mistake: urnsamples(ID, size = 3, replace = FALSE, ordered = TRUE) Thanks. Jay On Wed, Dec 3, 2008 at 12:04 AM, Kingsford Jones [EMAIL PROTECTED] wrote: However, I believe Brandon was trying to get the permutations of size 3, rather than combinations.

Re: [R] Create unique sets of 3 from a vector of IDs?

2008-12-02 Thread philozine
Dear all: These solutions work beautifully. Many, many thanks. And apologies for my lazy language! I did indeed mean permutations Best regards, Brandon --- On Wed, 12/3/08, G. Jay Kerns [EMAIL PROTECTED] wrote: From: G. Jay Kerns [EMAIL PROTECTED] Subject: Re: [R] Create unique sets