dump2vtk: empty vtk files due to invalid snapshot headers

[Dion Weatherley]

This is to document a known bug affecting some ESyS-Particle users, that results in production of "empty" vtk files when using the 'dump2vtk' tool. Most users notice this when trying to visualise simulations using Paraview.

It would appear to only affect users who have installed ESyS-Particle using pre-built packages (e.g. version 2.3.5) rather than installing from source obtained via the launchpad repository.

The problem appears to be a missing revision number in the headers of the ESyS-Particle snapshot/checkpointer files. An example of such a header is here:
V 3
10000
0.001
0
ESyS-Particle_2.3.4_bzr_rev.
BoundingBox -20 -20 -20 20 20 20
PeriodicBoundaries 0 0 0
Dimension 3D
snapshot_t=0_1.txt

The offending line is "ESyS-Particle_2.3.4_bzr_rev.". dump2vtk expects this line to contain both a string and a number, separated by white-space. When dump2vtk is executed over such faulty files, output similar to the following ensues:

$ dump2vtk -i snapshot -o test_ -t 0 1 100
version : 3
infilename : snapshot_t=0_0.txt
nr. of filenames: 0

The generated vtk file contains no points/cells e.g.

$head test_0.vtu
<VTKFile type="UnstructuredGrid" version="0.1">
<UnstructuredGrid>
<Piece NumberOfPoints="0" NumberOfCells="0">
<Points>
<DataArray NumberOfComponents="3" type="Float64" format="ascii">
</DataArray>
</Points>
<PointData Scalars="radius">
<DataArray type="Float64" Name="radius" NumberOfComponents="1" format="ascii">
</DataArray>

[Note that NumberofPoints="0" and NumberOfCells="0" above]

Workarounds:
1) uninstall the pre-built version of ESyS-Particle (sudo apt-get remove esys-particle) and install the latest version from the source code repository. Instructions for that are available here:
https://answers.launchpad.net/esys-particle/+faq/1613

2) In the folder containing faulty snapshot files, a quick fix is possible with this command:

$ sed -i -e 's/rev./rev. 1080/g' *_0.txt

This bug will be triaged and fixed prior to the next stable release of ESyS-Particle.