Reading xdmf file in the new version of dolfinx

General
1

Hello,

I would like to know how I can read an xdmf file in the new version of dolfinx. I know that there exists a tool called adios4dolfinx but I have not found any example regarding its implementation with an xdmf file. My xdmf file contains the mesh and a multiblock function.

2 
with XDMFFile(MPI.COMM_WORLD, "mesh.xdmf", "r") as xdmf:
    mesh = xdmf.read_mesh(name="Grid")
    ct = xdmf.read_meshtags(mesh, name="Grid")
mesh.topology.create_connectivity(mesh.topology.dim, mesh.topology.dim - 1)
with XDMFFile(MPI.COMM_WORLD, "mt.xdmf", "r") as xdmf:
    ft = xdmf.read_meshtags(mesh, name="Grid")

More detail are in Defining subdomains for different materials .

3

Thank you so much. My problem is more with displacements function, how can I read them? If I do the read_mesh I get the coordinates of the mesh but I think I do not get other functions

4

Mayabe you can re-mesh in python? For my case, I write a function to re-define the boundary in every time step.

5

Checkpointing of solutions (e.g., your displacement functions) is only available through adios4dolfinx, at least for the time being.

6

Thank you for your answers. Yes, it is only possible through adios4dolfinx but the examples I have seen they talk about a .bp file, not a xdmf file. When I try to repeat changing the extension, I get errors. However, in the description of the tool it says that it is possible. So I was wondering if there exists an example that I can follow to import the results I have saved in a xdmf file and use them again in dolfinx using that tool.

7

As I said, no, it does not. You can export in bp format using a writer which is different from XDMFFile (VTXFile, for instance), but you cannot read back in the solution.