Find the adjacent tetrahedron of a specific tetrahedron by vertex e?

[MatrixVector]

Dear Dr. Bouchut,

Thanks for your reply. Regarding that “finding the tetrahedra with a common vertex“, maybe the way using lists proposed by Prof. Hecht works better.

Mesh connectivity details

You want for each vertices of the mesh the list of triangle contening this vertex: // you can do that in few line of code: mesh Th=square(4,4); int[int] headv(Th.nv), next(Th.nt*3); headv=-1; // for(int k =0;k< Th.nt; ++k) for(int i =0;i< 3; ++i) { int v = Th[k][i]; // vertex number next[3k+i] = headv[v]; headv[v]= 3k+i; } // show the list of triangle of vertex v for(int v=0; v<Th.nv;++v) { cout << v << " : "; for(int p=headv[v]; p >=0; p=next[p]) { int k = p/3, i = p%3; ass…