Dear developers I tried to run ex24.c https://petsc.org/release/src/snes/tutorials/ex24.c.html using the following command line ./ex24 -sol_type quadratic -dm_plex_simplex 0 -field_petscspace_degree 1 -potential_petscspace_degree 1 -dm_plex_box_faces 2,1 I discovered that at 254: PetscCall(PetscWeakFormSetIndexBdResidual(wf, label, 1, 0, 0, 0, f0_bd_quadratic_q, 0, NULL)); reverses the value of the integrals at the top only. That isThe boundary integral corresponding to node 5 becomes that of 4 and vise-versa. Same thing for nodes 5 and 6. The mesh index is as follows *4---*5---*6 | | | | | |*1--- *2---*3 However, if I use -dm_plex_simplex 1 there is no problem. The model is in the form Au = b the value of b with "-dm_plex_simplex 0" is[0.25 0.0104167 0. 0. 0.145833 0. -0.583333 0.177083 0. 0.0833333 -0.28125 0. 0. -0.6875 0. -0.75 -0.364583 0.] and for -dm_plex_simplex 1 [0.0833333 0.0104167 0. 0. 0.145833 0. -0.583333 0.177083 0. 0.25 -0.260417 0. 1.43404e-16 -0.645833 0. -0.75 -0.427083 0.]
you can see that the value at node 1 =0.25 and node 4 = 0.0833333 ( simplex 0) which is reversed, that is, node 4 =0.25 and node 1 = 0.0833333 (simplex 1) So, my own calculation shows that at node 1 should be 0.083333 not 0.25.The -dm_plex_simplex 1 gives the correct answer but -dm_plex_simplex 0 gives wrong answer. Would you please help me in this matter. Sincerely yoursAzeddine M
