// Scilab ( http://www.scilab.org/ ) - This file is part of Scilab
// Copyright (C) INRIA - Serge Steer
//
// This file must be used under the terms of the CeCILL.
// This source file is licensed as described in the file COPYING, which
// you should have received as part of this distribution.  The terms
// are also available at
// http://www.cecill.info/licences/Licence_CeCILL_V2.1-en.txt

function [sl]=imrep2ss(v,deg)

    [lhs,rhs]=argn(0)
    // hankel
    [no,nv]=size(v);
    n=nv/2;
    ns1=no-1;n2=n-1;
    l=1;
    h=0*ones(n,n);
    for k=1:n,h(l:l+ns1,:)=v(:,k:k+n2),l=l+no,end;
    //factorization
    if rhs==1 then [u,h1,v1,deg]=svd(h);else [u,h1,v1]=svd(h);end
    //extraction
    obs=u(:,1:deg);con=h1*v1';con=con(1:deg,:);
    //shift
    obstild=obs(no+1:n*no,:);obstild(n*no,deg)=0;
    sl=syslin("d",obs'*obstild,con(:,1),obs(1:no,:))
endfunction