[Gmsh] Symmetry command, simple example please?

[Richard Crozier]

Hello,

I'm just getting started using gmsh and would like to use the Symmetry
command to mirror (and duplicate) elements in a plane. Could someone
possibly give me a simple example of using this command? The manual says
I must provide the coefficients of the plane equation, but how do I
obtain these? Can I extract these from a Plane Surface somehow?

Thanks,

Richard C.

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