Default parameters for NonLinearVariationalSolver

[nate]

If you want to do fancier things with preconditioning your system in conjunction with an iterative solver, I highly recommend migrating to DOLFINx. The Stokes demo is a great place to start.

Otherwise there are some old examples knocking around, e.g.,

https://bitbucket.org/fenics-project/dolfin/src/master/python/demo/undocumented/elasticity/demo_elasticity.py

Set krylov linear solver paramters in newton solver

Here is a silly example which should only be considered for its syntax. The preconditioner I’ve designed here is deliberately not a good approximation of the Jacobian. import matplotlib.pyplot as plt from dolfin import * class Problem(NonlinearProblem): def __init__(self, J, J_pc, F, bcs): self.bilinear_form = J self.preconditioner_form = J_pc self.linear_form = F self.bcs = bcs NonlinearProblem.__init__(self) def F(self, b, x): pass …