No, I have not checked it using Valgrind. Perhaps it will help me trace the problem.
Regards, Mukkund > On 18 Jun 2020, at 00:43, Dave May <dave.mayhe...@gmail.com> wrote: > > Is the code valgrind clean? > > On Wed, 17 Jun 2020 at 23:25, MUKKUND SUNJII <mukkundsun...@gmail.com > <mailto:mukkundsun...@gmail.com>> wrote: > I agree with the structured nature of the noise. I did play around with the > PetscFV implementation a bit to allow for the computation of different fluxes > left and right side of every interface. > > Nevertheless it is indeed strange that the problem disappears when I use a > PLEX dm. > > Regards, > > Mukkund > >> On 17 Jun 2020, at 22:53, Dave May <dave.mayhe...@gmail.com >> <mailto:dave.mayhe...@gmail.com>> wrote: >> >> >> >> On Wed 17. Jun 2020 at 21:21, MUKKUND SUNJII <mukkundsun...@gmail.com >> <mailto:mukkundsun...@gmail.com>> wrote: >> Yes, precisely! I am not sure how I can replicate using the original version >> of ex11.c because it does not support bathymetry. >> >> Regardless, to demonstrate the discrepancy, I have uploaded three plots. The >> scenario is a lake at rest. Essentially, you have a varying bathymetry but a >> level water surface. If the model is well balanced, then the water surface >> height must not change. The description of the files are below >> >> 1) Bathymetry.png : It shows you the bathymetry profile (z(x)) and the water >> surface height (H = h+z(x)) at t = 0. >> <Bathymetry.png> >> >> 2) Plex.png : This is the water surface height after 1 time step (0.007055 >> sec) and the dm type is Plex. As you can see, the water surface height is >> undisturbed as expected. >> <Plex.png> >> >> 3) P4est.png : This is the result after 1 time step (same final time) if I >> set the dm type as p4est. The noise is in the order of 1e-3 to be a little >> more specific. Since its not specifically at the boundaries and more or less >> spread throughout, it could indeed be noise introduced. But of course I >> could be wrong. >> <p4est.png> >> >> >> The (wrong) result has seemingly a lot of structure. Have you verified your >> code using p4est is valgrind clean? This looks too much like a weird >> indexing bug for me to not ask this question. >> >> Thanks, >> Dave >> >> >> Maybe this paints a better picture. >> >> Regards, >> >> Mukkund >> >> For your reference, the Riemann Solver is a modified version of the HLL >> solver: A simple well-balanced and positive numerical scheme for the >> shallow-water system by Emmanuel Audusse, Christophe Chalons, Philippe Ung. >> (https://www.intlpress.com/site/pub/files/_fulltext/journals/cms/2015/0013/0005/CMS-2015-0013-0005-a011.pdf >> >> <https://www.intlpress.com/site/pub/files/_fulltext/journals/cms/2015/0013/0005/CMS-2015-0013-0005-a011.pdf>) >> >>> On 17 Jun 2020, at 20:47, Mark Adams <mfad...@lbl.gov >>> <mailto:mfad...@lbl.gov>> wrote: >>> >>> So you get this noise with a regular grid in p4est. So the same grid as >>> will Plex, and you are not getting the same results. >>> >>> I don't know of any difference from p4est on a non-adapted grid. Can you >>> reproduce this with ex11? >>> >>> Matt and Toby could answer this better. >>> >>> >>> On Wed, Jun 17, 2020 at 1:33 PM MUKKUND SUNJII <mukkundsun...@gmail.com >>> <mailto:mukkundsun...@gmail.com>> wrote: >>> Greetings, >>> >>> I am a master’s student working on the shallow water model of the TS >>> example 'ex11.c' as part of my thesis. Therefore, I am working with >>> DMForest for the implementation of adaptive grids. I have a question and an >>> observation. >>> >>> I am trying to find relevant information about interpolation that takes >>> place through the routine DMForestTransferVec. Perhaps it could be my >>> inability to find it, but I am unable to locate the implementation of the >>> routine >>> >>> (forest->transfervec)(dmIn,vecIn,dmOut,vecOut,useBCs,time). >>> >>> Any information on this particular routine is highly appreciated. >>> >>> Furthermore, I have developed a well balanced Riemann Solver that includes >>> topography in the model. In the process of testing both the non-adaptive >>> and adaptive version, I found that my results differed when I changed the >>> type of DM. For instance, when I run a scenario in a fixed, non-adaptive >>> grid with a DM of type 'P4est', I find that the well balanced nature is >>> lost due to small perturbations all across the domain. However, this does >>> not occur when I use a DM of type ‘plex’. Is there a radical change in the >>> routines between the two DM’s? This is not as much of a question as it is >>> an observation. >>> >>> Thank you for all of your suggestions! >>> >>> Regards, >>> >>> Mukkund >
