Outputting

In the previous sections we have only considered continuous and discontinuous Lagrange elements. However, there is a large variety of elements that is supported in DOLFINx.

Many of these elements have functionals that are not point evaluations, and they span a large amount of different polynomials.

VTK, used in visualization in Pyvista and Paraview does not support most of these elements. However, they support arbitrary order Lagrange elements, which means that if we can interpolate or project the solution we would like to output into a P-th order space that is compatible, we can use Paraview/VTK to visualize the solution.

The engines VTXWriter and VTKFile in DOLFINx to write output compatible with Paraview.