Jacobian is fine.  Important: Make sure initial condition satisfies boundary conditions.  Also this reduces SNES iteration count to minimum (of one).
Jacobian is fine.  Important: Make sure initial condition satisfies boundary conditions.  Also this reduces SNES iteration count to minimum (of one).

bueler/p4pdes,bueler/p4pdes,bueler/p4pdes,bueler/p4pdes