[R] create matrices with constraint
Richard M. Heiberger
rmh at temple.edu
Sat Dec 13 06:20:57 CET 2014
I think you might be looking for incomplete block designs. See
Cochran and Cox 1957, page 481
for Plan 11.38
t=28, k=4, r=9, b=63, lambda=1, E=.78. Type I
This design might be the set of 4 x 7 matrices you are looking for.
On Fri, Dec 12, 2014 at 12:00 PM, Kathryn Lord
<kathryn.lord2000 at gmail.com> wrote:
> Dear all,
>
> Suppose that I have natural numbers 1 through 28.
>
> Based on these numbers, choose 4 numbers 7 times without replacement and
> make a 4 by 7 matrix, for example,
>
>> a1
> [,1] [,2] [,3] [,4] [,5] [,6] [,7]
> [1,] 1 5 9 13 17 21 25
> [2,] 2 6 10 14 18 22 26
> [3,] 3 7 11 15 19 23 27
> [4,] 4 8 12 16 20 24 28
>
> and again create another 4 * 7 matrix, say a2, in the same way; however,
> every element of each column in a2 does not exist in any column of a1 like
> this, e.g.
>
>> a2
> [,1] [,2] [,3] [,4] [,5] [,6] [,7]
> [1,] 1 2 3 4 5 6 7
> [2,] 8 9 10 11 12 13 14
> [3,] 15 16 17 18 19 20 21
> [4,] 22 23 24 25 26 27 28
>>
>
> and again create another 4 * 7 matrix, say a3, in the same way; however,
> every element of each column in a3 does not exist in any column of a1 and
> a2.
>
> Using same logic, I'd like to make the matrices (a3, a4, a5....) as many as
> possible.
>
>
> Any suggestion will be greatly appreciated.
>
> Best,
>
> Kathryn Lord
>
> [[alternative HTML version deleted]]
>
> ______________________________________________
> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
More information about the R-help
mailing list