Newtoniteration output / see solution / initial data

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See for example:
Newton’s method, The nonlinear Poisson demo and

Set krylov linear solver paramters in newton solver

I recommend designing your own NewtonSolver and setting the options using PETSc. Here’s a quick example based on the nonlinear poisson demo. import matplotlib.pyplot as plt from dolfin import * class Problem(NonlinearProblem): def __init__(self, J, F, bcs): self.bilinear_form = J self.linear_form = F self.bcs = bcs NonlinearProblem.__init__(self) def F(self, b, x): assemble(self.linear_form, tensor=b) for bc in self.bcs: bc.…

The initial residual is constructed from whatever you pass for the solution vector. In the example you’ve provided m.vector().