Dear Jordi, Firstly, welcome to the forum. Well, as this is a course assignment I think that its fair to assume that some course mentor should be available to guide you toward the solution to the problem. You say that you’ve had no luck on the course site forum — that’s a bit poor. Anyway, I wouldn’t want to give away the answer, but after skimming through your code and seeing your comment that
> I checked my basis functions and its gradients and seem to be correct I would say that you’re looking in the right sorts of places for the problem. Remember that in the finite element method we use basis functions to approximate the solution, and these need to evaluated in certain places where we form approximations for certain calculations. You’ve seem to have the “evaluated” part sorted, but what about the other part? What might need to change when you move from linear to higher order shape functions in order to ensure that those approximate calculations are performed accurately? I hope that my somewhat cryptic response will give you a nudge in the right direction. Oh, and I also hope that you take a look at our tutorial programs sometime to see how we typically code up FEM problems. It’s good to get a hand on the basics, but you might be pleased to know that the deal.II library does most of this for you in a clean and easy to understand manner. Best, Jean-Paul > On 28 Dec 2019, at 02:01, Jordi Parra Porcar <jordiparrapor...@gmail.com> > wrote: > > Dear all, > > I am new to this group. I wanted to ask for some help as I am unable to find > the solution to a problem. > I am following a course in Coursera called "The Finite Element Method for > problems in physics". The course first assignment it is about coding with > dealii. > I have posted in the Coursera forum but got no answer so, I am trying by here > just to see if I am lucky and someone give me a hand. > The issue that I have is that I can only solve the problem with 1st order > basis functions as with quadratic and cubic basis functions it gives me an > error related with the K global matrix. > I have been going around discussions but still unable to find where is the > problem. I checked my basis functions and its gradients and seem to be > correct. > I uploaded all the files related to the problem. Now the ./main executes the > problem=1 with order=1, that is the linear basis function. > > Thank you all in advance and happy ending of the year! > > Jordi, > > -- > The deal.II project is located at http://www.dealii.org/ > <http://www.dealii.org/> > For mailing list/forum options, see > https://groups.google.com/d/forum/dealii?hl=en > <https://groups.google.com/d/forum/dealii?hl=en> > --- > You received this message because you are subscribed to the Google Groups > "deal.II User Group" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to dealii+unsubscr...@googlegroups.com > <mailto:dealii+unsubscr...@googlegroups.com>. > To view this discussion on the web visit > https://groups.google.com/d/msgid/dealii/5a12993f-9687-4b5a-9ad5-e4711e49f6a4%40googlegroups.com > > <https://groups.google.com/d/msgid/dealii/5a12993f-9687-4b5a-9ad5-e4711e49f6a4%40googlegroups.com?utm_medium=email&utm_source=footer>. > <CMakeCache.txt><CMakeLists.txt><FEM1.h><Makefile><cmake_install.cmake><main1><main1.cc><writeSolutions.h><_b66323d90964cccb91c92f77bcb02ab0_codingAssign1.pdf> -- The deal.II project is located at http://www.dealii.org/ For mailing list/forum options, see https://groups.google.com/d/forum/dealii?hl=en --- You received this message because you are subscribed to the Google Groups "deal.II User Group" group. To unsubscribe from this group and stop receiving emails from it, send an email to dealii+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/dealii/75B2F41E-2A31-49E9-BBB6-5B165B871BB7%40gmail.com.
