FEPointEvaluation: ordering of DoF/shape functions

[Michał Wichrowski]

Dear all,

It seems that FEPointEvalaution::evaluate and ::integrate assume order of degrees of freedom as if it was returned from cell->get_dof_indices() even if StidedArrayView is passed. This is contrary to what is stated in the documentation:
https://www.dealii.org/developer/doxygen/deal.II/classFEPointEvaluation.html#a3a5c60eb2d57403c4670922f23a62e55

The tests in non_matching only compare using FE_DGQ element on which ordering of DoF is lexycographic, identical as in FEEvaluation

Anyway, I think that different ordering of DoF indicated only by the type of provided data is a potential source of bugs that are hard to find. There is no way to catch that through an assertion, maybe it would be possible to set force the user to explicitely state the ordering of DoF as a function argument? Although I do not have a good idea how to do it while maintaining backward compatibility.

For me, it took4 days to figure out what exactly is going on

Best,

Michał