[R] randomize a matrix

Alex Brown alex at transitive.com
Fri Oct 20 08:50:04 CEST 2006


hi Cameron

	It so happens that the particular example P you chose has no  
partners under the symmetry you describe.

	Can you explain what this is to be used for?

	Could you also give an example of what the operation you desire  
might look like if it was successful, and show exactly what you mean  
by row and column sums?  Does the order of row and column sums have  
to stay the same, ie:

	is

	0 1
	0 0

	symmetric with

	1 0
	0 0

	or not?

-Alex Brown

On 19 Oct 2006, at 20:49, Guenther, Cameron wrote:

> Hello everyone,
>
> If I have an incidence matrix of 0 and 1's
>
> P=[1 1 1 1 1 1
>    1 1 1 1 0 0
>    1 1 1 0 0 0
>    1 1 1 0 0 0
>    1 1 0 0 0 0]
>
> I want to create a new uniform random matrix [a] that is filled  
> with 0's
> and 1's but constrained so that the row and column sums are the  
> same as
> in [P].  Does anyone know how to accomplish this?
>
> Thanks in advance
>
> Cameron Guenther, Ph.D.
> Associate Research Scientist
> FWC/FWRI, Marine Fisheries Research
> 100 8th Avenue S.E.
> St. Petersburg, FL 33701
> (727)896-8626 Ext. 4305
> cameron.guenther at myfwc.com
>
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