[R] enumerates all possible combinations

[ken knoblauch]

does expand.grid do what you want?

expand.grid(c(0, 1), c(0, 1), c(0, 1))
   Var1 Var2 Var3
1    0    0    0
2    1    0    0
3    0    1    0
4    1    1    0
5    0    0    1
6    1    0    1
7    0    1    1
8    1    1    1


> Hi all R users,
> I want to create a matrix having n columns and 2^n rows, and all its 
> entries
> are only 0 or 1. In each row, column i is 0 means dimension i is 
> chosen, 0
> means not.  The matrix will contains all the possible combination of 
> those n
> dimensions.
>
> Here is an example, if n = 3, the matrix will look like:
> 0 0 0
> 0 0 1
> 0 1 0
> 1 0 0
> 0 1 1
> 1 0 1
> 1 1 1
>
>
> I know I can use n "for" loops to do this, but is there a better way?
> Thanks,
> -zm
>
> 	[[alternative HTML version deleted]]
>
>