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MATLAB function producing Alan Edelman's matrix for which det is computed as the wrong integer.
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function A = edelman | |
%EDELMAN Alan Edelman's matrix for which det is computed as the wrong integer. | |
% A = EDELMAN is a 27-by-27 matrix of 1s and -1s for which the | |
% MATLAB det function returns an odd integer, though the exact | |
% determinant is an even integer. | |
A = [% | |
1 1 1 1 -1 -1 -1 1 1 -1 1 -1 -1 1 -1 1 -1 1 -1 -1 -1 -1 -1 1 -1 -1 -1 | |
1 -1 -1 1 -1 1 -1 -1 -1 -1 -1 1 -1 -1 -1 -1 -1 1 -1 -1 -1 -1 1 -1 1 1 1 | |
-1 1 -1 -1 1 1 1 1 1 -1 1 -1 1 1 1 1 -1 -1 1 -1 -1 1 1 -1 1 1 -1 | |
-1 -1 1 -1 -1 -1 -1 1 -1 -1 -1 -1 1 -1 1 -1 -1 1 1 -1 -1 1 -1 -1 -1 -1 -1 | |
-1 1 1 -1 -1 -1 -1 -1 1 -1 -1 1 1 1 -1 -1 -1 -1 -1 1 1 1 -1 1 1 1 -1 | |
1 1 1 1 1 1 -1 1 -1 -1 1 1 -1 1 -1 -1 1 1 -1 -1 1 1 1 1 -1 1 -1 | |
-1 -1 -1 -1 -1 -1 1 -1 1 -1 1 -1 1 -1 1 1 1 1 1 -1 1 -1 1 -1 -1 1 -1 | |
1 1 1 -1 1 1 -1 -1 1 1 -1 -1 1 1 -1 1 -1 1 1 1 1 1 -1 -1 1 1 -1 | |
-1 1 -1 1 1 1 -1 -1 1 -1 1 1 1 1 -1 1 1 1 -1 1 1 -1 1 1 1 -1 -1 | |
-1 1 -1 1 1 -1 -1 -1 -1 1 1 1 1 1 -1 1 -1 1 1 -1 -1 1 1 1 1 -1 -1 | |
-1 -1 -1 -1 1 1 -1 -1 -1 1 1 -1 -1 1 -1 -1 1 1 1 1 -1 1 1 1 -1 -1 1 | |
1 1 -1 -1 1 -1 -1 -1 1 -1 -1 -1 -1 -1 -1 1 -1 1 -1 1 1 -1 1 1 1 -1 -1 | |
-1 1 -1 -1 -1 -1 1 -1 -1 -1 -1 1 -1 -1 1 1 -1 1 -1 -1 1 1 -1 -1 1 -1 -1 | |
1 1 -1 1 1 -1 1 1 -1 -1 -1 1 1 1 1 -1 -1 1 -1 1 1 -1 1 -1 -1 1 -1 | |
-1 1 -1 1 -1 1 1 1 -1 -1 1 1 -1 -1 -1 -1 -1 1 1 1 1 1 -1 1 1 -1 -1 | |
-1 -1 1 -1 1 -1 1 -1 -1 1 -1 -1 -1 -1 -1 -1 1 -1 1 -1 1 1 -1 1 -1 -1 1 | |
1 1 -1 1 1 -1 1 -1 -1 1 1 -1 -1 1 -1 -1 1 1 -1 1 -1 1 1 -1 1 1 -1 | |
1 1 -1 1 1 -1 1 1 1 -1 1 -1 1 -1 1 1 1 1 -1 -1 -1 1 1 1 -1 1 1 | |
1 -1 -1 -1 1 -1 1 -1 -1 -1 -1 1 1 -1 -1 1 1 -1 -1 -1 1 -1 1 1 1 1 -1 | |
-1 -1 -1 1 1 -1 1 -1 1 -1 1 1 1 1 1 -1 -1 -1 -1 -1 -1 1 1 1 -1 -1 -1 | |
1 1 -1 -1 -1 -1 -1 -1 -1 -1 1 1 1 -1 -1 1 -1 -1 1 -1 -1 1 1 -1 -1 -1 1 | |
-1 -1 1 1 -1 -1 1 -1 -1 -1 1 -1 1 -1 -1 1 1 -1 1 -1 1 1 -1 1 -1 1 -1 | |
-1 1 -1 1 1 1 1 1 -1 1 -1 1 -1 1 -1 1 1 1 1 1 1 1 1 -1 -1 -1 1 | |
-1 -1 1 1 1 -1 -1 -1 1 -1 1 -1 -1 1 -1 -1 -1 -1 1 -1 -1 1 1 1 1 1 -1 | |
1 1 1 1 1 -1 1 -1 1 -1 -1 1 1 -1 -1 1 1 1 -1 1 -1 -1 1 1 -1 1 1 | |
1 -1 1 -1 1 -1 1 1 -1 1 -1 1 1 -1 1 -1 -1 1 -1 -1 1 1 1 -1 1 -1 -1 | |
1 -1 1 1 -1 -1 1 1 1 -1 1 1 -1 1 1 1 1 1 -1 1 -1 1 -1 1 1 -1 1]; |
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It's been awhile since Alan's name has been associated with MATLAB code ;-)