I have this RuntimeError and I taught it was the mesh which was causing the problem.

What I did was to change the following mesh sizes in GMSH to create different meshes but still had the same error.

size0==0.1

size1==0.01

size2==0.05

size3==0.025

size4==0.5

size5==1

Can someone please help me understand what the error is?

Newton iteration 50: r (abs) = 2.905e-08 (tol = 1.000e-10) r (rel) = 2.984e-05 (tol = 1.000e-06)

Traceback (most recent call last):

File “/Users/bernard/Desktop/working/SEIRD_var-jia.py”, line 162, in

solve(F == 0, u, solver_parameters={“newton_solver”: {“relative_tolerance”: 1e-6}})

File “/Users/bernard/anaconda3/envs/project/lib/python3.8/site-packages/dolfin/fem/solving.py”, line 220, in solve

_solve_varproblem(*args, **kwargs)

File “/Users/bernard/anaconda3/envs/project/lib/python3.8/site-packages/dolfin/fem/solving.py”, line 266, in _solve_varproblem

solver.solve()

RuntimeError: