[Paraview] trying to achieve odd symmetry reflection where axis is inside original domain

[Noah Reddell]

Hi,

	I’ve simulated a problem in 2D where an odd symmetry boundary condition is applied across the x=0 plane.  I now want to visualize the full domain.
	There seem to be three complications making Paraview capabilities that I currently know about not workable.  Maybe other’s can point out a pipeline that works.  If I need a programmable filter, so far I am lost at what to implement.
	1)  My original data extends beyond the x=0 symmetry plane by two data points.  And I have no data point on x=0 itself.  This is because in the simulation, there is a third-order polynomial element centered on x=0.
	2)  My data is represented as Structured Curvilinear Grid (.VTS files) though in actuality, it is rectilinear.
	3)  Some data arrays have odd symmetry, such that f(x<0) = -f(x>0)

Here’s what I’ve tried.
A) Use the Reflect filter, reflect about x=0.  Works quite well for even symmetry data, but the odd-symmetry data is misrepresented with opposite sign for (x<0).  Also, there are glitches with the doubled-up mesh points about x=0.  That becomes obvious when I tried to add a calculator to correct the odd symmetry based on (x<0) boolean expression.
B) Manually select data points with (x>0); Extract Selection; Reflect that extraction; Group original and new selection.  Problem:  I end up with a band of missing data for the cell centered on x=0.

Ideally, I want to end up with a consistent full-domain representation such that I can perform stream line traces across the x=0 mid-plane.

I’d be very grateful if anyone could point out a working solution.   Here’s one of my data files and some screenshots of my failed attempts.  ( The scalar data item EM_field_n_c4 is a good odd-symmetry example. )

VTS data file 800 kB <https://dl.dropboxusercontent.com/u/54478577/supporting%20forum%20posts/paraview_odd_symmetry_help/harris_current_sheet_equilibreum_2.vts>

Existing Curvilinear Mesh representation <https://dl.dropboxusercontent.com/u/54478577/supporting%20forum%20posts/paraview_odd_symmetry_help/By.jpg>

ProblemA demonstration of missing band about x=0 <https://dl.dropboxusercontent.com/u/54478577/supporting%20forum%20posts/paraview_odd_symmetry_help/missingband.jpg>

ProblemB demonstration of glitch at centerline <https://dl.dropboxusercontent.com/u/54478577/supporting%20forum%20posts/paraview_odd_symmetry_help/glitch_at_centerline.jpg>


Best Regards,

Noah Reddell
University of Washington

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://public.kitware.com/pipermail/paraview/attachments/20151101/d533a362/attachment.html>