expected_A = [-1, 0, 0, 0, 0; ...
              -16, 32,  -16,  0,  0; ...
	      0,   -16, 32,  -16, 0; ...
	      0,   0,   -16, 32, -16; ...
	      0,   0,   0,   0,  -1];

unit_test_equals("Homework #1 problem #1 Poisson matrix is correct", ...
		 true, ...
		 expected_A == poisson_matrix(4, 0, 1));
