function info = try2(A,pin);

% TRY2 : test SUPERLU with 2 outputs

%

% info = try2(A,pin);

% normally info is the residual norm; 

% but info is at least 10^6 if U is not triangular

% or if the factors contain explicit zeros.

% Copyright (c) 1995 by Xerox Corporation.  All rights reserved.

% HELP COPYRIGHT for complete copyright and licensing notice.

n = max(size(A));

info = 0;

if nargin == 1

    [l,u] = superlu(A);

elseif nargin == 2

    [l,u] = superlu(A,pin);

else 

    error('requires 1 or 2 inputs');

end;

figure(2); spy(l); title('L');

figure(1); spy(u); title('U');

drawnow;

format compact

disp('SUPERLU with 2 outputs:');

if any(any(triu(l,1)))

    disp('L is *NOT* lower triangular.');

else

    disp('L is lower triangular.');

end;

if nnz(l) == nnz(l+l)

    disp('L has no explicit zeros.');

else

    disp('L contains explicit zeros.');

    info = info+10^6;

end;

if any(any(tril(u,-1)))

    disp('U is *NOT* upper triangular.');

    info = info + 10^6;

else

    disp('U is upper triangular.');

end;

if nnz(u) == nnz(u+u)

    disp('U has no explicit zeros.');

else

    disp('U contains explicit zeros.');

    info = info+10^6;

end;

if nargin == 1

    rnorm = norm(A - l*u,inf);

    fprintf(1,'||A -  L*U|| = %d\n', rnorm);

elseif size(pin) == [n n]

    rnorm = norm(A*pin' - l*u,inf);

    fprintf(1,'||A*PIN'' -  L*U|| = %d\n', rnorm);

elseif max(size(pin)) == n

    rnorm = norm(A(:,pin) - l*u,inf);

    fprintf(1,'||A(:,PIN) -  L*U|| = %d\n', rnorm);

else

    rnorm = norm(A - l*u,inf);

    fprintf(1,'||A -  L*U|| = %d\n', rnorm);

end;

info = info + rnorm;

disp(' ');