Re: [deal.II] bug in program only with adaptive mesh refinement

> > OK, so F_i would then be (f(u),\varphi_i), right? > > I think the question is whether you do or do not apply > ConstraintMatrix::condense to F. I never really know whether you do or > do not have to do that when you want to use F that way, so I typically > just assemble the (scalar number)

Re: [deal.II] bug in program only with adaptive mesh refinement

> > ...which you compute via quadrature? Or do you compute a vector F that > corresponds to f(u) somehow? > > If you go the route via vectors you have to pay attention to *what kind > of vector you have*, namely one that does or does not incorporate > constraints. Dealing with dual space vecto

[deal.II] Re: bug in program only with adaptive mesh refinement

> > The vectors you have in this equation P(u+h*v) =..., which of those have > constrains distributed and which zeroed? > If you assembly matrices with ConstraintMatrix.distribute_local_to_global() > the diagonal elements corresponding to constrained DoFs > ... > Along the same lines: does yo

Re: [deal.II] bug in program only with adaptive mesh refinement

Hi Wolfgang, thanks for looking! > * In the formula above, P(.) is a functional, I assume, i.e., it takes a > function and returns a number, right? > * If so, what exactly does > f(u) . v > actually mean? How do you compute this? > * Same for the second derivatives? > Sorry if that w

[deal.II] bug in program only with adaptive mesh refinement

Hi all -- I'm writing a library that involves solving a nonlinear elliptic PDE, which I'll write as f(u) = 0. There is an exact solution for this PDE for a certain simplified geometry. To test everything, I check that my numerical solution is tolerably close to the analytic solution, with both

Re: [deal.II] WorkStream iterator

So glad I asked this question instead of reinventing the wheel :) I was mostly working off the Boussinesq and elasticity examples, so I missed step-35. On Sunday, June 19, 2016 at 3:18:33 PM UTC-7, bangerth wrote: > > On 06/19/2016 04:12 PM, Daniel Shapero wrote: > > I'm wor

[deal.II] WorkStream iterator

I'm working on a problem which involves iterating over the DoFHandlers of both a scalar and a vector field at the same time, similar to step 31 . I'm creating an iterator class which will wrap