# ngsolve.comp.MeshNode

Hi,

I tried to retrieve the vertices coordinate using netgen 6.2, following example from:1.8 Exploring the mesh topology — NGS-Py 6.2.2302 documentation

but i get this message : AttributeError: ‘ngsolve.comp.MeshNode’ object has no attribute ‘point’

Is this feature not available in netgen 6.2?

Best,

never mind, i have it resolved
thanks

I was able to get the coordinate of the vertices, but how do i get the nodal coordinates used in finite element spaces (fes). i could show the nodal in each element , such as :
fes = H1(mesh, order=3)
for el in fes.Elements(VOL):
print(el.dofs[5])

how to get the coordinates of el.dofs[5] ?

Thanks

Hi,
our dofs are associated with mesh nodes (vertices, edges, faces, cells), but not with geometric coordinates. Only vertex nodes have coordinates.
Typically we are using hierarchical (modal) basis functions.
Joachim

Hi,

Thansk for your reply. So, could you please help to further elaborate this hierarchical basis function assignment flow?
How to find what the el.ndofs[i] (where i >=4) 's related vertices are. ( i know the first 4 are just the vertices of the tetrahedral cell (in 3D case) and the other 6 ndofs (e.g, case of order=2) are computed from the first 4). and also, are these (4+6) ndofs mapped in serially in GridFunction(fes) ?

Futhermore, suppose i have a solution (dimension Nsol), and i want to load/map it into fes, how do i do it correctly?

Best,
Alex

Hi,

for the general concept of hierarchical high order finite elements have a look into literature such as Leszek Demkowicz “Computing with hp-Adaptive Finite Elemens”, or the thesis of Sabine Zaglmayr:
http://www.numa.uni-linz.ac.at/Teaching/PhD/Finished/zaglmayr

to see a prototype implementation of high-order elements have a look into the C++ tutorials my-little-ngsolve:

The actual basis used in NGSolve does not belong to the documented user interface. It should not be relevant to the NGSolve-users. The basis may also change between versions.

Joachim