dolfin team mailing list archive

[Garth Wells <question138742@xxxxxxxxxxxxxxxxxxxxx>]

Question #138742 on DOLFIN changed:
https://answers.launchpad.net/dolfin/+question/138742

    Status: Open => Answered

Garth Wells proposed the following answer:

On 22/12/10 16:10, B. Emek Abali wrote:
> New question #138742 on DOLFIN:
> https://answers.launchpad.net/dolfin/+question/138742
>
> hi, where can I find what VariationalProblem(...nonlinear=True...) is really doing, I can follow until the cpp.py where the classes have been defined, but cannot find the .cpp data where the functions are written, my aim to find out is why,
>

Look in dolfin/fem/VariationalProblem.cpp

> if I use my own Newton iteration procedure, like
> ...
> problem = VariationalProblem(G, F, bcs=bc, ...)
> dv = problem.solve()
> differ = dv.vector().array()
> eps = numpy.linalg.norm(differ, ord=2)
> print 'K=%g : after iteration=%d , the L2-Norm of perturbation: %g ' % (mat['K'],iter, eps)
> v.vector()[:] += dv.vector()
> ...
>

The above code doesn't apply non-zero Dirichlet bcs correctly for a 
Newton method.

Garth


> vs. the automatized one
> ...
> problem = VariationalProblem(G, F, bcs=bc, nonlinear=True, ...)
> problem.solve(v)
> ...
>
> they do not have the same convergence tendency, neither the same solution (if both would converge to one)?
>

-- 
You received this question notification because you are a member of
DOLFIN Team, which is an answer contact for DOLFIN.