# Axis Symmetric Postprocessing

Hi there, I’m learning Elmer for electromagnetic simulations. I’m also using the opportunity to learn and use Paraview.

The main goal is to compare FEMM 2D and Elmer 2D.

For Cartesian problems, I can integrate variables (Paraview) over surfaces and get the exact same results.

However, after different types of trials, I can’t reproduce the results for axis Symmetric solution. After reading other topics, my doubt remains. Thus I decided to ask.

Does Paraview knows that the result is axis Symmetric by default?

If I integrate variables over surface, I was expecting to get a volume, not an area. Also, I get a wrong contour plot.

Probably, I just need brainstorming to understand if this can be a paraview problem, as it doesn’t seems to be Elmer solution problem.

https://www.elmerfem.org/forum/viewtopic.php?t=8231

I’ve posted the link for the Elmer fórum. I hope not to break any rules.

ParaView has no idea if your geometry is symmetric or not and does not make such assumption.

From my understanding, to integrate the result (axis symmetric) using Paraview, I need to convert it to 3D and than integrate.

I can do that using Transform → Rotate Extrusion.

However, I still get the wrong integral result. Probably I’m not selecting the entire body?
Any suggestion?

Is there a way to convert x,y to r,z?

If you know the axis of rotation, computing r and z should be trivial.

Hi @mwestphal , I do know the axis of rotation. Can you give me a tip of how to calculate it?

You should be able to find that on the internet without issues, here is one

Really sorry about the confusion. It is clear how to convert (mathematically speaking). However, it’s unclear how to manipulate coordinates in paraview. I can only view Variables Results.

I’m still learning paraview, the workflow and filters are not completely clear.

Should I use a specific filter or I should use calculator? If so, where can I see the list of available variables?

Thx

Indeed, Calculator and PythonCalculator should let you compute that easily

Best,