function test9
%TEST9 test metis, etree, bisect, nesdis
% Example:
%   test9
% See also cholmod_test

% Copyright 2006-2023, Timothy A. Davis, All Rights Reserved.
% SPDX-License-Identifier: GPL-2.0+

fprintf ('=================================================================\n');
fprintf ('test9: test metis, etree, bisect, nesdis\n') ;

% Prob = ssget ('LPnetlib/lp_qap15') ;
Prob = ssget ('HB/bcsstk15')                                                %#ok
A = Prob.A ;
C = A'*A ;
R = A*A' ;

fprintf ('\nmetis:\n') ;
tic ; p0 = metis (R) ; toc                                                  %#ok
% [pa po] = etree2 (R (p0,p0)) ; sparse (po - (1:size(R,1)))

tic ; p1 = metis (C) ; toc                                                  %#ok
% [pa po] = etree2 (C (p1,p1)) ; sparse (po - (1:size(C,1)))

tic ; p2 = metis (C, 'sym') ; toc                                           %#ok
% [pa po] = etree2 (C (p1,p1)) ; sparse (po - (1:size(C,1)))

tic ; p3 = metis (A, 'row') ; toc                                           %#ok
% [pa po] = etree2 (A (p1,:), 'row') ; sparse (po - (1:size(A,1)))

tic ; p4 = metis (A, 'col') ; toc                                           %#ok
% [pa po] = etree2 (A (:,p1), 'col') ; sparse (po - (1:size(A,2)))

fprintf ('\nmetis(A):\n') ;
[m n] = size(A) ;
if (m == n)
    if (nnz (A-A') == 0)
        tic ; p5 = metis (A) ; toc
        % spy (A (p5,p5)) ;
        [ignore q] = etree (A(p5,p5)) ;
        p5post = p5 (q) ;                                                   %#ok
        % spy (A (p5post,p5post)) ;
        lnz0 = sum (symbfact (A (p5,p5)))                                   %#ok
    end
end

fprintf ('\namd:\n') ;
if (m == n)
    if (nnz (A-A') == 0)
        tic ; z0 = amd2 (A) ; toc                                           %#ok
        lnz = sum (symbfact (A (z0,z0)))                                    %#ok
    end
end

fprintf ('\nbisect:\n') ;
tic ; s0 = bisect (R) ; toc                                                 %#ok
tic ; s1 = bisect (C) ; toc                                                 %#ok
tic ; s2 = bisect (C, 'sym') ; toc                                          %#ok
tic ; s3 = bisect (A, 'row') ; toc                                          %#ok
tic ; s4 = bisect (A, 'col') ; toc                                          %#ok


fprintf ('\nnested dissection:\n') ;
tic ; [c0 cp0 cmem0] = nesdis (R) ; toc                                     %#ok
tic ; [c1 cp1 cmem1] = nesdis (C) ; toc                                     %#ok
tic ; [c2 cp2 cmem2] = nesdis (C, 'sym') ; toc                              %#ok
tic ; [c3 cp3 cmem3] = nesdis (A, 'row') ; toc                              %#ok
tic ; [c4 cp4 cmem4] = nesdis (A, 'col') ; toc                              %#ok

fprintf ('\nnested_dissection(A):\n') ;
if (m == n)
    if (nnz (A-A') == 0)
        tic ; c5 = nesdis (A) ; toc                                         %#ok
        lnz1 = sum (symbfact (A (c5,c5)))                                   %#ok
    end
end

fprintf ('test9 passed\n') ;