How to generate an *M^N* by *N* integer matrix consiting of all possible length N row vectors whose elements are between 0 and M-1?

2 views (last 30 days)
I need to generate an M^N by N matrix consisting of all possible length N (N>=2) row vectors whose elements are integer numbers between 0 and M-1 (M>=2). Since there are a total of M^N such row vectors, the matrix has M^N rows, each corresponding to one particular row vector. I also want the row vectors in an "incremental" order, for example, when M = 2 and N = 3, I want to generate the following matrix:
0 0 0
0 0 1
0 1 0
0 1 1
1 0 0
1 0 1
1 1 0
1 1 1
In my code, a typical value of M would be 16 and N would be 3. So my matrix would be a large matrix. Does anybody know how to generate such a matrix in an efficient way?

Accepted Answer

Jan on 8 Apr 2013
There are several corresponding submissions in the FileExchange. When speed matters, use FEX: VChooseKRO. When you do not want to compile C-code, try FEX: combinator.
Using UINT8 arrays will save a lot of RAM and processing time.
Peng Liu
Peng Liu on 13 Apr 2013
Edited: Peng Liu on 13 Apr 2013
Hi Jan,
With your help I solved this problem. Recently, I also solve this problem in a different way using Matlab built-function. So I would like to share it with you.
M = 2; N = 3; % M^N by N integer matrix
levels = M*ones(1,N);
Int_Matrix = fliplr(fullfact(levels))-1

Sign in to comment.

More Answers (1)

Walter Roberson
Walter Roberson on 5 Apr 2013
with the adjustment by Chris Torek.
I don't think I have posted the MATLAB code, but it is not difficult to write.
  1 Comment
Peng Liu
Peng Liu on 8 Apr 2013
Thanks for you reply. But I couldn't find the answer to my question from the link. Could you provide the Matlab code?

Sign in to comment.

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by