Does mfem support 2nd order triangular elements?

[AlemayehuB]

Hello, I'm new user and have been creating meshes of simple 2D shapes with netgen and gmsh that implement 2nd order triangular elements. However when I run glvis on these meshes I encounter a segmentation fault.

netgen> Mesh -> Meshing Options:
select "Second order elements"
select "Mesh granularity" = very fine
netgen> Mesh -> Generate Mesh
netgen> File -> Export mesh -> <name.mesh>

ng2-to-mfem.sh <name.mesh> <newname.mesh>

I've done the same thing without selecting "Second order elements" and glvis runs without any issues.

The following is a sample input that gave me issues:

`
areamesh2

8
1 1 5 11
1 5 2 12
2 2 6 13
2 6 3 14
3 3 7 15
3 7 4 16
4 4 8 17
4 8 1 18
10
1 3 1 5 9
1 3 2 9 5
1 3 2 6 10
1 3 2 10 9
1 3 3 10 6
1 3 3 7 10
1 3 4 10 7
1 3 4 8 10
1 3 1 9 8
1 3 8 9 10
29
0.000000 -1.000000
1.000000 0.000000
0.000000 1.000000
-1.000000 0.000000
0.707107 -0.707107
0.707107 0.707107
-0.707107 0.707107
-0.707107 -0.707107
0.151753 -0.409423
-0.072105 0.222714
0.368095 -0.929788
0.929788 -0.368095
0.929788 0.368095
0.368095 0.929788
-0.368095 0.929788
-0.929788 0.368095
-0.929788 -0.368095
-0.368095 -0.929788
0.429430 -0.558265
0.075877 -0.704711
0.575877 -0.204711
0.317501 0.464910
0.463947 0.111357
0.039824 -0.093354
-0.036053 0.611357
-0.389606 0.464910
-0.536053 0.111357
-0.389606 -0.242196
-0.277677 -0.558265
`

Thank You!

[tzanio]

Yes we do support second order (actually arbitrary) order triangular elements.

I don't believe we have tested NETGEN in a while though, and their format may have changed. Do you mind sharing the input file and which NETGEN version you used?

Tzanio

[AlemayehuB]

Hi I think the issue might have been on my end.

Thank You!