nschloe/meshio

FlowVC compatible mesh format

raptistasos opened this issue · 2 comments

raptistasos commented

Hi and thanks for the great tool that is meshio!

May I request a new format for unstructured mesh data to be compatible with the FlowVC tool that facilitates the calculation of finite-time Lyapunov exponent (FTLE) fields.

Format specification

The format is detailed here, https://shaddenlab.berkeley.edu/uploads/releasenotes.pdf

nschloe commented

I would need some example files to play around with it.

raptistasos commented

Thanks for the interest.

Here you can download some example data. In the folder, you will find the input data (/data/input) and the configuration file (/data/input/FTLE_example.in). Also download (Linux64) the two executables (flowVC and bin2vtk) and place them in the path (e.g. /usr/local/bin). The output data (FTLE field) are generated by running the command (in /data/input),

flowVC FTLE_example.in

and are converted to vtk (to check in ParaView) by the command (in /data/output),

bin2vtk 5 2 dg_forwardFTLE 0 10 1 dg_forwardFTLE (the meaning of the arguments is described in the configuration file)

The provided example though refers to a structured mesh, which is not the common case.

For unstructured data, the program requires the following binary files,
InFilePrefix_coordinates.bin, InFilePrefix_connectivity.bin, InFilePrefix_adjacency.bin

Please check their format in paragraph 3.2.2 of the release notes

It would be great if meshio could provide these files. Besides the mesh, FlowVC requires the velocity data to be provided in a specific format (paragraph 3.1), which is outside the scope of meshio. I am using FEniCS for some flow simulations, so I think I can convert the output velocity data into the required format.