Add custom Newton's method example #85
Conversation
There was a problem hiding this comment.
Looks perfect! Thanks for putting it together @jorgensd
It would be a good resource for anyone trying to implement their own Newton's method/nonlinear solver
| # Compute norm of update | ||
| correction_norm = dx.vector.norm(0) | ||
| print(f"Iteration {i}: Correction norm {correction_norm}") | ||
| if correction_norm < 1e-10: |
There was a problem hiding this comment.
I guess this is fine too, but shouldn't one check the norm of L for a termination criterion.
There was a problem hiding this comment.
I didn't see that it is verified further down the line that L.norm(0) is indeed small. Either way it fine!
There was a problem hiding this comment.
There are many ways of terminering a Newton solver. I might add a section on that later, as one could Also compute the residual of the Newton solver (Which is different to L(uh), if uh does not satisfy the boundary condition).
| dx_norm.append(correction_norm) | ||
|
|
||
| print(f"Iteration {i}: Correction norm {correction_norm}, L2 error: {L2_error[-1]}") | ||
| if correction_norm < 1e-10: |
There was a problem hiding this comment.
I am guessing this corresponds to "incremental" as the convergence_criterion when using an inbuilt newton solver.
[Update] Indeed it is!
Addresses #60. @bhaveshshrimali could you have a look and see what you think?