[petsc-users] HDF5 and ParaView

[Lawrence Mitchell]

> On 13 Jul 2020, at 10:46, Matthew Knepley <knepley at gmail.com> wrote:
> 
> For now its complexity of moving simulation data around and scripting for it. However, now I have at least two meshes in my problem, and
> I anticipate having several more. I believe this will be the long term trend.
>  
> I would probably move out of VTK files in favor of something else if I had a way to encode VTK's (the library, not the file format) high-order Lagrange elements.
> Actually, I'm toying with dumping files with PETSc's raw binary I/O with MPI, and writing a proper ParaView plugin in Python to read the data.
> 
> I have again discussed higher order with the Firedrake people. They are using the Paraview mechanism, but it is so fragile and baroque that I
> refuse. Currently, the cleanest way is still to refine the mesh and project to P_1. There have been so many attempts at high order in VTK, I can
> only conclude that Kitware does not give a crap about it.

FWIW, they went with an approach to defining a basis, it just disagrees with what you want. 

Lisandro, in terms of using XDMF rather than VTK files for high order Lagrange. There appears to be work going on at the moment to add support in the VTK XDMF-reader for these elements: https://gitlab.kitware.com/vtk/vtk/-/merge_requests/7068

You still have to map your basis to theirs, of course.

Lawrence