halbux / sparselizard

C++ FEM library | user-friendly | multi-physics | hp-adaptive | HPC
http://www.sparselizard.org
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Extra points getting written to .vtu files? #40

Closed caseyjamesdavis closed 3 years ago

caseyjamesdavis commented 3 years ago

Hi Alex,

When using the following code : image

Sparselizard correctly reports that there are 5 nodes and 4 elements: image

When I open the .vtu file in Paraview it reports 8 nodes or points and 4 elements: image

Inside the .vtu file there appears to be double reporting of the internal points and also the scalar of 3.14 that was written to the mesh. image

A similar thing happens in 2D if the shape is switched from "line" to "quadrangle": image

Sparselizard reports correctly: image

Paraview reports many extra points. image

Using the paraview filter 'clean to grid' appears to remove the extra points.

Any ideas?

Cheers, Casey

main.cpp.txt

halbux commented 3 years ago

Hi Casey, that's normal behavior w.r.t what I wrote. I ll have a look at it if I can indeed avoid that. But in any case I should be able to store expressions that are discontinuous between elements, therefore I will have to check if I can still allow that without the duplicated points in the paraview file (in gmsh .pos for example I really need it).

Alex

halbux commented 3 years ago

After a quick look it seems to me the duplicates are needed for the piecewise continuous case.

Try saving grad(T).write where T has a jump in slope at a mesh node.

Alex

caseyjamesdavis commented 3 years ago

Hi Alex,

I had wondered if it was the result of some other functionality that I was less familiar with. I will experiment with grad(T).write.

Thanks for taking the time to investigate and explain.

Casey