How do I export the results of mixed formulation?

[dokken]

If you search for this error on the forum

@lilac

Degree of output Function must be same as mesh degree. Maybe the Function needs to be interpolated?

You get the following posts where I explain what is going on

TypeError: BoundingBoxTree.__init__() takes 2 positional arguments but 3 were given

Meshtags now require the geometry as second input The decision of having to explicitly interpolate into a supported XDMF-file function space (will be a continuous lagrange space of same order as the mesh geometry) was made to highlight that this makes a loss of accuracy and can be an expensive operation. If you are using higher order Lagrange/DG elements, you should use VTKFile or VTXWriter, as they support this kind of output. If you are using other spaces, such as RT, Nedelec etc, they sho…