1 ---------- Testing Jacobian ------------- 2 Run with -snes_test_jacobian_view and optionally -snes_test_jacobian <threshold> to show difference 3 of hand-coded and finite difference Jacobian entries greater than <threshold>. 4 Testing hand-coded Jacobian, if (for double precision runs) ||J - Jfd||_F/||J||_F is 5 O(1.e-8), the hand-coded Jacobian is probably correct. 6 ||J - Jfd||_F/||J||_F = 1.98363e-12, ||J - Jfd||_F = 7.88431e-09 7