Paraview 5.10 error messages

1

One year ago I wrote some Fenics code and visualized the results with paraview 5.9. Now - on a new computer - i’m using paraview 5.10 an get with the same data following error message:

ERROR: In C:\glr\builds\paraview\paraview-ci\build\superbuild\paraview\src\VTK\IO\XML\vtkXMLPDataReader.cxx, line 372
vtkXMLPUnstructuredGridReader (0000021E44FDFCA0): Piece cell data array connectivity not found

ERROR: In C:\glr\builds\paraview\paraview-ci\build\superbuild\paraview\src\VTK\IO\XML\vtkXMLPDataReader.cxx, line 372
vtkXMLPUnstructuredGridReader (0000021E44FDFCA0): Piece cell data array offsets not found

The files are generated (as last year) by

vtkfileT = File(‘t_modell/solutionTemperature.pvd’)
…
vtkfileT << (T, 0)

The Fenics version is rather new, i.e. installed today (how to find the version?).

What do I have to change?

2

I cannot reproduce your issue running the following code:

from dolfin import *
from dolfin import __version__ as version
print(version)
mesh = UnitSquareMesh(10, 10)
V = FunctionSpace(mesh, "DG", 0)

u = interpolate(Expression("x[0]", degree=1), V)
File("u.pvd") << u

which returns:

2019.1.0

and the file opens nicely in Paraview:

paraview --version
paraview version 5.10.0-RC1
1 Like
3

Hmmm … I checked the same with paraview 5.9 and get the same error.

On my Ubuntu 20.04 (WSL2) I get

sudo apt list fenics
> fenics/focal,now 1:2019.1.0.3 amd64 [installed]

pip3 freeze | grep fenics

fenics-dijitso==2019.1.0
fenics-dolfin==2019.1.0
fenics-ffc==2019.1.0.post0
fenics-fiat==2019.1.0
fenics-ufl==2019.1.0

Seems to depend the implemented problem, since I get also no error with your example :frowning:

4

If you could make a minimal example (similar to mine above) that can reproduce your issue I can look further into it.

5

Well, it’s an entire program with external meshes. I don’t want to upload it in a public space because of confidentiality. Reducing it to the core might take some time …

6

Try with built in meshes (and make some fake boundary conditions for uniquness).
You should not even need to solve any problem, just create a vector in the appropriate space and save it to file.

7

Here is a minimal example to reproduce the error:

from dolfin import *
import mshr
from dolfin import __version__ as version

comm = MPI.comm_world
rank = MPI.rank(comm)

if rank==0:
    print(version)

bl = Point(0,0)
tr = Point(1,1)
geom = mshr.Rectangle(bl,tr)
mesh = mshr.generate_mesh(geom, 100)

V = FunctionSpace(mesh, "CG", 2)

u = interpolate(Expression("x[0]", degree=1), V)
File("test.pvd") << u.leaf_node()

XDMFFile('test.xdmf').write(u)

which runs in parallel with MPI:

mpirun -np 2 python3 testmpi.py

and returns:

2019.1.0

When I try to open the PVD file in ParaView 5.10.1, it gives a bunch of errors:

(3977.191s) [pvserver        ]  vtkXMLPDataReader.cxx:372    ERR| vtkXMLPUnstructuredGridReader (0x14e52b20): Piece cell data array connectivity not found
(3977.191s) [pvserver        ]  vtkXMLPDataReader.cxx:372    ERR| vtkXMLPUnstructuredGridReader (0x14e52b20): Piece cell data array offsets not found
(3977.191s) [pvserver        ]  vtkXMLPDataReader.cxx:372    ERR| vtkXMLPUnstructuredGridReader (0x14e52b20): Piece cell data array types not found
(3977.229s) [pvserver        ]  vtkXMLPDataReader.cxx:354    ERR| vtkXMLPUnstructuredGridReader (0x14e52b20): Piece point data array f_19 not found

But one can still open the XDMF file in ParaView without any problems.

Conclusion
There are several necessary ingredients to reproduce the error:
MPI + mshr + 2nd order continuous Galerkin + export to PVD

My recommendation
Use XDMF instead of PVD files.