Question on extending mesh boundaries

PyLith
1

Hello,

I’m currently running Pylith 4.1.1 and I’m trying to create a new mesh using Gmsh with wider boundaries. However, there’s an error with generating the mesh when I tried to extend the boundary (x-axis) -2500 km to 2500 km while using DX_FAULT = 5.0e+3 and DX_BIAS = 1.09. I can only generate the mesh at this boundary when the DX_BIAS = 1.099.

I’ve attached the necessary files here (the “generate_gmsh_boundary_error.txt” has to be converted to a “.py”). Thanks!

generate_gmsh_boundary_error.txt (12.7 KB)

slab_bot_geom_linear_v4.txt (6.8 KB)
slab_top_geom_linear_v4.txt (6.8 KB)

2

In the future, please include the error message you see. That way, we can verify that we are able to reproduce your error.
I get the following error message when I use your mesh generation script:

./generate_gmsh.py --generate --gui
Info    : Meshing 1D...
Info    : [  0%] Meshing curve 3 (Nurb)
Info    : [ 10%] Meshing curve 4 (Line)
Info    : [ 20%] Meshing curve 5 (Line)
Info    : [ 30%] Meshing curve 8 (Line)
Info    : [ 30%] Meshing curve 9 (Line)
Info    : [ 40%] Meshing curve 10 (Nurb)
Info    : [ 50%] Meshing curve 11 (Nurb)
Info    : [ 60%] Meshing curve 12 (Nurb)
Info    : [ 60%] Meshing curve 13 (Nurb)
Info    : [ 70%] Meshing curve 14 (Nurb)
Info    : [ 80%] Meshing curve 15 (Line)
Info    : [ 80%] Meshing curve 16 (Line)
Info    : [ 90%] Meshing curve 17 (Line)
Info    : [100%] Meshing curve 18 (Line)
Info    : Done meshing 1D (Wall 0.0577142s, CPU 0.119331s)
Info    : Meshing 2D...
Info    : [  0%] Meshing surface 1 (Plane, Frontal-Delaunay)
Warning : Impossible to recover edge 605 605 (error tag -1)
Warning : Impossible to recover edge 607 607 (error tag -1)
Error   : Unable to recover the edge 611 (15/55) on curve 10 (on surface 1)
Traceback (most recent call last):
  File "Downloads/tmp/./generate_gmsh.py", line 307, in <module>
    App().main()
  File "software/unix/py3.12-venv/pylith-debug/lib/python3.12/site-packages/pylith/meshio/gmsh_utils.py", line 110, in main
    self.generate_mesh(args.cell)
  File "Downloads/tmp/./generate_gmsh.py", line 302, in generate_mesh
    gmsh.model.mesh.generate(2)
  File "software/unix/py3.12-venv/pylith-debug/lib/python3.12/site-packages/gmsh.py", line 2060, in generate
    raise Exception(logger.getLastError())
Exception: Unable to recover the edge 611 (15/55) on curve 10 (on surface 1)

The error goes away when I change curve 10 (top of the model) from a spline (add_spline) to a polyline (add_polyline). I think there is a problem with creating the spline for your points as they are almost colinear.

3

Hi Brad,

Thank you for your help and I will make sure to include it next time, thanks!