I would like to write Paraview data in binary to save space. I saw that VTKFile takes a file_mode argument. I tried setting it to wb without success. Looking at the source code I think this argument is unused but I could be wrong. Here is an MVP: from dolfinx import mesh, io, fem from mpi4py import…

If you are only using first order Lagrange and DG-0, I would use XDMFFile. Merging datasets with VTXWriter (.bp) would be trick as of now. I did make a PR for DG-0 fields with VTXWriter: Support DG-0 functions in VTXWriter by jorgensd · Pull Request #3107 · FEniCS/dolfinx · GitHub which in theory (…

Use VTXWriter (with engine=“BP4”). As of now VTKFile only supports ascii.

The issue with VTXWriter is that I can’t mix node and cell data the way VTKFile allows me to. MVP: from dolfinx import mesh, io, fem from mpi4py import MPI nels_per_side = 2 mesh = mesh.create_unit_square(MPI.COMM_WORLD, nels_per_side, nels_per_side, mesh.CellType.quadrilateral) V = fem.function…

[image] dokken: If you are only using first order Lagrange and DG-0, I would use XDMFFile. About this, XDMF is a bit buggy when you write multiple functions. I reported this in this issue . Not only it duplicates the data so that it occupies more memory, the coloring of a dataset can be “hidde…

[image] ordinary-slim: About this, XDMF is a bit buggy when you write multiple functions. I reported this in this issue . Not only it duplicates the data so that it occupies more memory, This is not true. If you look at the actual xdmf-file, the data is: <?xml version="1.0"?> <!DOCTYPE Xdmf S…

I’ve added a fix to the VTK duplicate piece issue at: Move piece node outside of function loop in VTKFile by jorgensd · Pull Request #3120 · FEniCS/dolfinx · GitHub

[image] dokken: You need to use the Extract Block filter in Paraview to view each individual block in the dataset. I tried to follow your steps but I am only shown a single block in the extract block and nothing special happens, see picture below: [extractBlock] I am not familiar with XDMF…

Thank you, I managed to get it to work by using a different Paraview reader. Was using Xdmf3_Reader_S and with Xdmf3_Reader_T it works for me even without the extract_block. [image] dokken: This is not true. If you look at the actual xdmf-file, the data is: I was talking about RAM. In the in…

This is a Paraview issue, not a storage/DOLFINx issue. We provide pointers to the same data in the h5 file for both of them. As I mentioned earlier, XDMF is no longer maintained by its developers (Kitware) and is not a format that is receiving updates in Paraview. Thus there is very little we will …

Thanks for the help and information, much appreciated!

How to write binary data with VTK/XDMFFile?

General

dokken April 4, 2024, 2:25pm 9

You need to select the correct block in the top right left corner, see:

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Converting legacy FEniCS code to FEniCSx causes issue

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How to write binary data with VTK/XDMFFile?

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