Will Pazner

> is it normal that this function > > ``` > PCG(A, M, B, X, 1, 200, 1e-12, 0.0); > ``` > > needed to go so far away? >...

> The later needs 46 iterations, while the former needs 69. What's special about LORSolver that it's more efficient than a GSSmoother with lor bilinearform as operator? I haven't looked...

> Recently, I have been working with VTK Lagrange cells. I can confirm that they work on equidistant points in the parametric space. For the node ordering, I found [this...

> Should we be worried about the possibility that parts of mfem or external codes rely on the `null` pointer, to distinguish linear from high-order meshes? > > My guess...

This PR is now [under review](https://github.com/mfem/mfem/blob/master/CONTRIBUTING.md#pull-requests) (see the table in the PR description). To help with the review process, please **do not force push** to the branch.

Given @mlstowell's comments, this is liable to be a breaking change in actual user code (though I do agree with @YohannDudouit that we want to move in the direction of...

Lowest-order Nédélec DOFs correspond to the mesh edges, and lowest-order Raviart-Thomas DOFs correspond to the mesh faces. Note that `FiniteElementSpace` provides functions `GetVertexDofs`, `GetEdgeDofs`, and `GetFaceDofs` that will give you...

> I think it is also important to include a note on the webpage: https://mfem.org/mesh-formats/ so users can discover this information without combing through the source code. PR for the...

> The logic for only comparing the `rows` and `cols` partitionings as pointers is used in other places too, I think. It's probably best to factor out the full comparison...

> Looks good to me. Thanks @pazner Thanks, @liruipeng. BTW, is there any update on hypre-space/hypre#168? Is `hypre_ParCSRMatrixReadIJ` essentially deprecated?