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## Re: Matlab rref equivalent?

 From: Dirk Laurie Subject: Re: Matlab rref equivalent? Date: Tue, 16 May 2000 08:46:52 +0200 (SAST)

```=?ISO-8859-1?Q?St=E9fan_van_der_Walt?= skryf:
>
> Hi,
>
> How do one reduce a matrix to row echelon or reduced row echelon form in
> Octave? (rref func in matlab for example)
>
> Regards,
> Stefan van der Walt
>

function [R,k]=rref(A,tol)
% reduced row echelon form
[m,n]=size(A); p=max(m,n);
if nargin<2, tol=p*eps*norm(A,inf); end
% pad matrix with zeros to make it square
if m~=n, A(p,p)=0; end
[L,U,P]=lu(A);
k=find(abs(diag(U))>tol);
R=U(k,k)\U(k,:);
% remove added columns if any, add correct number of zero rows
if n<p, R(:,n+1:p)=[]; end
if length(k)<m, R(m,n)=0; end
endfunction

Dirk

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