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From: leo leonardo on 21 Apr 2010 16:09
How can i calculate the rank of logical Matrix A in a in GF(2)(2) ?

In matlab to do it i schould at first use the function A_gf=gf(A,1) to creates a Galois array GF(2) from the matrix A.
then i schould calculate the rank from the function A_rank=rank(A_gf)

the problem the function rank change the matrix to double (by the function full) before calculate the rank of it.which means if I have a big logical matrix (like 32000*64000) matlab can't do it (the message from matlab is out of memory).
the question How can i calculate the rank of logical Matrix in GF(2) without change the matrix to full?

thank for your help
From: Bruno Luong on 21 Apr 2010 17:22
Using RANK() on GF(2) is totally incorrect, even if apply on tiny matrix.

The correct way is programming your own algorithm of Gaussian elimination with pivoting on GF(2).

Bruno
From: leo leonardo on 21 Apr 2010 17:59
"Bruno Luong" <b.luong(a)fogale.findmycountry> wrote in message <hqnq9t$18v$1(a)fred.mathworks.com>...
> Using RANK() on GF(2) is totally incorrect, even if apply on tiny matrix.
>
> The correct way is programming your own algorithm of Gaussian elimination with pivoting on GF(2).
>
> Bruno

thank you for your answer.but why i can't example use the function gfrank(A,2) but its problem also it takes really very long time?
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