function info = try3(A,pin); % TRY3 : test SUPERLU with 3 outputs % % info = try3(A,pin); % normally info is the residual norm; % but info is at least 10^6 if the factors are not triangular, % or the permutation isn't a permutation. % 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,pr] = superlu(A); elseif nargin == 2 [l,u,pr] = 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 3 outputs:'); if any(any(triu(l,1))) disp('L is *NOT* lower triangular.'); info = info + 10^6; 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 pr == [1:n] disp('PROW is the identity permutation.'); elseif isperm(pr) disp('PROW is a non-identity permutation.'); else disp('PROW is *NOT* a permutation.'); info = info + 10^6; end; if nargin == 1 rnorm = norm(A(pr,:) - l*u,inf); fprintf(1,'||A(PROW,:) - L*U|| = %d\n', rnorm); elseif size(pin) == [n n] rnorm = norm(A(pr,:)*pin' - l*u,inf); fprintf(1,'||A(PROW,:)*PIN'' - L*U|| = %d\n', rnorm); elseif max(size(pin)) == n rnorm = norm(A(pr,pin) - l*u,inf); fprintf(1,'||A(PROW,PIN) - L*U|| = %d\n', rnorm); if pr == pin disp('PROW is the same as the input permutation.'); else disp('PROW is different from the input permutation.'); end; else rnorm = norm(A(pr,:) - l*u,inf); fprintf(1,'||A(PROW,:) - L*U|| = %d\n', rnorm); end; info = info + rnorm; disp(' ');