Funes el memorioso

>> A=100*eye(50);A(1,2:50)=1;A(2:50,1)=1;
>> subplot(2, 2, 1);
>> spy(A, 'b.');
>> title('A');
>> subplot(2, 2, 2);
>> spy(A([2:50,1],[2:50,1]'), 'b.');
>> title('reordered A');
>> subplot(2, 2, 3);
>> spy(chol(A), 'b.');
>> title('chol(A)');
>> subplot(2, 2, 4);
>> spy(chol(A([2:50,1], [2:50,1]')), 'b.');
>> title('chol(reordered A)');