On Tue, Jul 05, 2011 at 07:49:51AM +0100, Garth N. Wells wrote: > > > On 05/07/11 07:24, Anders Logg wrote: > > On Mon, Jul 04, 2011 at 11:46:00PM +0100, Garth N. Wells wrote: > >> > >> > >> On 04/07/11 23:37, Anders Logg wrote: > >>> On Mon, Jul 04, 2011 at 11:28:56PM +0100, Garth N. Wells wrote: > >>>> > >>>> > >>>> On 04/07/11 17:22, Anders Logg wrote: > >>>>> On Mon, Jul 04, 2011 at 04:47:46PM +0100, Garth N. Wells wrote: > >>>>>> > >>>>>> > >>>>>> On 04/07/11 16:44, Anders Logg wrote: > >>>>>>> On Mon, Jul 04, 2011 at 04:39:04PM +0100, Garth N. Wells wrote: > >>>>>>>> I'm not sold on the NonlinearVariationalProblem interface. I would > >>>>>>>> prefer a constructor takes the Jacobian as an argument. It's much > >>>>>>>> cleaner to do things at construction and removes the need to later > >>>>>>>> attach the Jacobian. > >>>>>>> > >>>>>>> The point is that one should be able to define a nonlinear problem > >>>>>>> with or without a Jacobian. Not all nonlinear solvers need a Jacobian. > >>>>>>> > >>>>>> > >>>>>> That's why I wrote 'a' constructor. We can have two versions. > >>>>> > >>>>> Yes, that's an option. The drawback with that is that it would double > >>>>> the number of constructors (from 6 to 12) but it's a small thing to > >>>>> fix. I wouldn't mind moving it to the constructor. > >>>>> > >>>> > >>>> I think that we can rationalise the number of constructors in > >>>> FooVariationalProblem. For the shared pointer versions, it would be > >>>> enough to have just > >>>> > >>>> LinearVariationalProblem(boost::shared_ptr<const Form> a, > >>>> boost::shared_ptr<const Form> L, > >>>> boost::shared_ptr<Function> u, > >>>> std::vector<boost::shared_ptr<const BoundaryCondition> > bcs); > >>>> > >>>> and > >>>> > >>>> NonlinearVariationalProblem(boost::shared_ptr<const Form> F, > >>>> boost::shared_ptr<const Form> J, > >>>> boost::shared_ptr<Function> u, > >>>> std::vector<boost::shared_ptr<const BoundaryCondition> > bcs); > >>> > >>> I think it's important that we keep the same argument order as for the > >>> reference versions, and that the Jacobian comes last to emphasize > >>> that it is an optional/auxiliary argument. It also removes some of the > >>> confusion we had be for with (a, L) vs (F, J). How about this: > >>> > >>> LinearVariationalProblem(boost::shared_ptr<const Form> a, > >>> boost::shared_ptr<const Form> L, > >>> boost::shared_ptr<Function> u, > >>> std::vector<boost::shared_ptr<const > >>> BoundaryCondition> > bcs); > >>> > >>> NonlinearVariationalProblem(boost::shared_ptr<const Form> F, > >>> int rhs, > >>> boost::shared_ptr<Function> u, > >>> std::vector<boost::shared_ptr<const > >>> BoundaryCondition> > bcs, > >>> boost::shared_ptr<const Form> J); > >>> > >>> Same as your suggestion (just one shared ptr constructor in each > >>> class) but placing the Jacobian last and keeping the right-hand side > >>> in there. > >>> > >> > >> I'm don't mind the order being the same (I didn't pay any attention to > >> it). My main point is that the shared_ptr interface is lower level so we > >> don't need to provide multiple convenience versions. > > > > Agree. > > > >>> Keeping the right-hand side is important since it makes it possible to > >>> check for errors (like a nonzero right-hand side) in one single > >>> place (inside NonlinearVariationaProblem.cpp). We would otherwise need > >>> to check it inside Equation.cpp and possibly in the Python layer. > >>> > >> > >> I don't like it. It makes the nonlinear interface clumsy. Reading > >> the signature it's not clear to me what it's for or what I should > >> pass in. > > > > The point is that it makes the interface for all variational problems > > (linear or nonlinear) the same: > > > > lhs, rhs, solution, [bcs], [jacobian] > > > > I think this is helpful to minimize errors. > > > > I don't agree. It's confusing. It's not clear to me why I would want to > pass a pointless integer to a NonlinearVariationalProblem. I wouldn't > expect a pointless argument, so I would start to wonder what it should > be and what it's for.
Looks like this is a matter of taste. Other opinions? -- Anders _______________________________________________ Mailing list: https://launchpad.net/~dolfin Post to : [email protected] Unsubscribe : https://launchpad.net/~dolfin More help : https://help.launchpad.net/ListHelp
