// Scilab ( http://www.scilab.org/ ) - This file is part of Scilab
// Copyright (C) INRIA -
//
// 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]=markp2ss(markpar,n,nout,nin)
    // Given a set of n (matrix) Markov parameters stacked in the (row)-matrix
    // markpar of size nout x (n*nin) markp2ss
    // returns a state-space linear system Sl (syslin list) such that with:
    // A=sl(2); B=sl(3); C=sl(4);
    // C*B = markpar(1:nout,1:nin),
    // C*A*B =marpar(1:nout,nin+1:2*nin),....
    // See also: pol2des
    //!

    nmax=max(size(markpar));
    H=[];H(n*nout,n*nin)=0;
    p=markpar;
    l1=1:nout;k1=1;
    H(l1,:)=p;kset=(nmax-nin+1):nmax;zeroing=0*ones(nout,nin);
    for k=2:n;
        l1=l1+nout*ones(l1);
        k1=k1+nin;
        p=markpar(:,k1:nmax);p(nout,nmax)=0;
        H(l1,:)=p;
    end;
    [u,s,v,deg]=svd(H);
    obs=u(:,1:deg);con=s*v(1:deg,:)';
    obstild=obs(nout+1:n*nout,:);obstild(n*nout,deg)=0;
    Sl=syslin("c",obs'*obstild,con(1:deg,1:nin),obs(1:nout,:))
endfunction