function test9
%TEST9 test cs_qr
%
% Example:
%   test9
% See also: testall

%   Copyright 2006-2007, Timothy A. Davis.
%   http://www.cise.ufl.edu/research/sparse

rand ('state', 0) ;

index = UFget ;
[ignore f] = sort (max (index.nrows, index.ncols)) ;
f = f (1:100) ;
clf

% f = 185 ;
% f = 449 ;
% f = 186

for i = f
    Prob = UFget (i) ;
    disp (Prob) ;
    A = Prob.A ;
    [m n] = size (A) ;
    if (m < n)
        A = A' ;
    end
    [m n] = size (A) ;
    sp = sprank (A) ;
%    if (sprank (A) < min (m,n))
%       continue
%    end


    for cmplex = 0:double(~ispc)

        if (cmplex)
            A = A + 1i * sprand (A) ;
        end

        Aorig = A ;

        A = A (:, colamd (A)) ;
        s1 = svd (full (A)) ;

        if (cmplex)
            try
                tic ;
                R = chol (A'*A) ;
                t1 = toc ;                                                  %#ok
            catch
                fprintf ('chol (A''*A) failed\n') ;
                R = [ ] ;
            end
        else
            tic ;
            R = qr (A) ;
            t1 = toc ;                                                      %#ok
        end

        % tic ;
        % [Q,R] = qr (A) ;
        % t1 = toc ;

        [c,h,parent] = symbfact (A, 'col') ;
        rnz = sum (c) ;                                                     %#ok
        tic ;
        [V2,Beta2,p,R2] = cs_qr (sparse(A)) ;
        t2 = toc ;                                                          %#ok

        v2 = full (V2) ;
        if (any (spones (v2) ~= spones (V2)))
            error ('got zeros!') ;
        end

        C = A ;
        m2 = size (V2,1) ;
        if (m2 > m)
            C = [A ; sparse(m2-m, n)] ;
        end
        C = C (p,:) ;

    %    [H1,R1] = myqr (C) ;
    %    err1 = norm (R1-R2,1) / norm (R1)
    %    % [svd(A) svd(R1) svd(full(R2))]
    %    s2 = svd (full (R2)) ;
    %    err2 = norm (s1 - s2) / s1 (1) 
    %    fprintf ('%10.6f %10.6f  cs speedup %8.3f sprank %d n %d\n', ...
    %   t1, t2, t1/t2, sp, n) ;
    %    err2

        % left-looking:
        [V,Beta3,R3] = qr_left (C) ;                                        %#ok
        s3 = svd (full (R2)) ;
        err3 = norm (s1 - s3) / s1 (1) ;
        disp ('err3 = ') ; disp (err3) ;
        if (err3 > 1e-12)
            error ('!') ;
        end

        % right-looking:
        [V,Beta4,R4] = qr_right (C) ;                                       %#ok
        s4 = svd (full (R2)) ;
        err4 = norm (s1 - s4) / s1 (1) ;
        disp ('err4 = ') ; disp (err4) ;
        if (err4 > 1e-12)
            error ('!') ;
        end

        % H2 = full (H2)
        % R2 = full (R2)

        subplot (2,4,1) ; spy (A) ;             title ('A colamd') ;
        subplot (2,4,2) ; spy (C) ;             title ('A rperm') ;
        subplot (2,4,3) ; treeplot (parent) ;
        subplot (2,4,4) ; spy (Aorig) ; title ('Aorig') ;
        subplot (2,4,5) ; spy (abs(R2)>0) ;     title ('spqr R, no zeros') ;
        subplot (2,4,6) ; spy (R) ;             title ('matlab R') ;
        subplot (2,4,7) ; spy (R2) ;    title ('spqr R') ;
        subplot (2,4,8) ; spy (V2) ;    title ('spqr V') ;
        drawnow

    %    if (err2 > 1e-9)
    %   error ('!') ;
    %    end
        if (m2 > m)
            fprintf ('added %d rows, sprank %d n %d\n', m2-m, sp, n) ;
        end
        % pause
    end

end
