2 unit_test_equals("The identity is positive definite", ...
4 is_positive_definite(A));
7 unit_test_equals("All-ones matrix is not positive definite", ...
9 is_positive_definite(A));
11 A = [5,1,2;1,6,3;2,3,7];
12 unit_test_equals("A diagonally-dominant matrix is positive definite", ...
14 is_positive_definite(A));