From 67b527d383aefffd4a62392ddf623dea1cc45a7a Mon Sep 17 00:00:00 2001
From: Magdalena Schreter <magdalena.schreter@tum.de>
Date: Wed, 15 May 2024 09:06:14 +0200
Subject: [PATCH] make FE_Nothing and FE_DGQ consistent

---
 doc/news/9.4.0-vs-9.5.0.h                          |  2 +-
 doc/news/changes/minor/20240118Schreter            |  2 +-
 doc/news/changes/minor/20240219SchreterRitthaler   |  2 +-
 examples/step-85/step-85.cc                        |  2 +-
 include/deal.II/lac/affine_constraints.templates.h |  2 +-
 include/deal.II/matrix_free/shape_info.h           |  4 ++--
 include/deal.II/matrix_free/tools.h                | 10 +++++-----
 tests/hp/fe_nothing_05.cc                          |  2 +-
 tests/hp/fe_nothing_06.cc                          |  2 +-
 tests/hp/fe_nothing_07.cc                          |  2 +-
 tests/hp/fe_nothing_12.cc                          |  2 +-
 tests/hp/fe_nothing_13.cc                          |  2 +-
 tests/hp/fe_nothing_14.cc                          |  2 +-
 tests/hp/solution_transfer_03.cc                   |  2 +-
 tests/mpi/hp_step-4.cc                             |  5 +++--
 15 files changed, 22 insertions(+), 21 deletions(-)

diff --git a/doc/news/9.4.0-vs-9.5.0.h b/doc/news/9.4.0-vs-9.5.0.h
index abdd443ca1..e355b7897f 100644
--- a/doc/news/9.4.0-vs-9.5.0.h
+++ b/doc/news/9.4.0-vs-9.5.0.h
@@ -1052,7 +1052,7 @@ inconvenience this causes.
   New: The new class MatrixFreeTools::ElementActivationAndDeactivationMatrixFree
   is a wrapper around MatrixFree designed to deal with
   DoFHandler objects involving cells without degrees of freedom, i.e.,
-  cells using FENothing as element type. The class helps to implement the
+  cells using FE_Nothing as element type. The class helps to implement the
   "element birth and death technique".
   <br>
   (Peter Munch, Sebastian Proell, 2022/07/09)
diff --git a/doc/news/changes/minor/20240118Schreter b/doc/news/changes/minor/20240118Schreter
index 3021b4753a..2931ce6990 100644
--- a/doc/news/changes/minor/20240118Schreter
+++ b/doc/news/changes/minor/20240118Schreter
@@ -1,4 +1,4 @@
 Changed:
-FE_DGQ::get_interpolation_matrix() now also takes as a source element FENothing.
+FE_DGQ::get_interpolation_matrix() now also takes as a source element FE_Nothing.
 <br>
 (Magdalena Schreter, Peter Munch, 2024/01/18)
diff --git a/doc/news/changes/minor/20240219SchreterRitthaler b/doc/news/changes/minor/20240219SchreterRitthaler
index bf1f8986b0..e77acd6ccd 100644
--- a/doc/news/changes/minor/20240219SchreterRitthaler
+++ b/doc/news/changes/minor/20240219SchreterRitthaler
@@ -1,3 +1,3 @@
-Fixed: Fix make_flux_sparsity_pattern for a FECollection containing FENothing elements. 
+Fixed: Fix make_flux_sparsity_pattern for a FECollection containing FE_Nothing elements. 
 <br>
 (Magdalena Schreter-Fleischhacker, Andreas Ritthaler, 2024/02/19)
diff --git a/examples/step-85/step-85.cc b/examples/step-85/step-85.cc
index 7bf39154d2..5afa0d2ed3 100644
--- a/examples/step-85/step-85.cc
+++ b/examples/step-85/step-85.cc
@@ -359,7 +359,7 @@ namespace Step85
                                                       level_set);
 
     // As we iterate over the cells, we don't need to do anything on the cells
-    // that have FENothing elements. To disregard them we use an iterator
+    // that have FE_Nothing elements. To disregard them we use an iterator
     // filter.
     for (const auto &cell :
          dof_handler.active_cell_iterators() |
diff --git a/include/deal.II/lac/affine_constraints.templates.h b/include/deal.II/lac/affine_constraints.templates.h
index 87dec4533c..06172a6da3 100644
--- a/include/deal.II/lac/affine_constraints.templates.h
+++ b/include/deal.II/lac/affine_constraints.templates.h
@@ -4714,7 +4714,7 @@ AffineConstraints<number>::add_entries_local_to_global(
   const size_type n_local_cols = col_indices.size();
 
   // Early return if the length of row and column indices is zero, relevant
-  // for the usage with FENothing.
+  // for the usage with FE_Nothing.
   if (n_local_cols == 0 && n_local_rows == 0)
     return;
 
diff --git a/include/deal.II/matrix_free/shape_info.h b/include/deal.II/matrix_free/shape_info.h
index 96d88ed373..b3d5252464 100644
--- a/include/deal.II/matrix_free/shape_info.h
+++ b/include/deal.II/matrix_free/shape_info.h
@@ -430,9 +430,9 @@ namespace internal
        * Return whether an element is supported by MatrixFree.
        *
        * The following scalar elements are supported:
-       * - FENothing, FE_DGP, and FE_Q_DG0
+       * - FE_Nothing, FE_DGP, and FE_Q_DG0
        * - polynomial tensor-product elements based on
-       *   Polynomials::Polynomial (FE_Q, FE_DG_Q, FE_DGQArbitraryNodes,
+       *   Polynomials::Polynomial (FE_Q, FE_DGQ, FE_DGQArbitraryNodes,
        *   FE_DGQHermite, FE_DGQLegendre) or Polynomials::PiecewisePolynomial
        *   (FE_Q_iso_Q1).
        * - elements for simplex, pyramids, and wedges (FE_SimplexP,
diff --git a/include/deal.II/matrix_free/tools.h b/include/deal.II/matrix_free/tools.h
index f56436f9f0..73f77159f6 100644
--- a/include/deal.II/matrix_free/tools.h
+++ b/include/deal.II/matrix_free/tools.h
@@ -160,10 +160,10 @@ namespace MatrixFreeTools
   /**
    * A wrapper around MatrixFree to help users to deal with DoFHandler
    * objects involving cells without degrees of freedom, i.e.,
-   * cells using FENothing as element type.  In the following we call such cells
-   * deactivated. All other cells are activated. In contrast to MatrixFree,
-   * this class skips deactivated cells and faces between activated and
-   * deactivated cells are treated as boundary faces.
+   * cells using FE_Nothing as element type.  In the following we call such
+   * cells deactivated. All other cells are activated. In contrast to
+   * MatrixFree, this class skips deactivated cells and faces between activated
+   * and deactivated cells are treated as boundary faces.
    */
   template <int dim,
             typename Number,
@@ -196,7 +196,7 @@ namespace MatrixFreeTools
      *
      * @note At the moment, only DoFHandler objects are accepted
      * that are initialized with FECollection objects with at most
-     * two finite elements (i.e., `FENothing` and another finite
+     * two finite elements (i.e., `FE_Nothing` and another finite
      * element).
      */
     void
diff --git a/tests/hp/fe_nothing_05.cc b/tests/hp/fe_nothing_05.cc
index decae2ecf8..5b25902d6e 100644
--- a/tests/hp/fe_nothing_05.cc
+++ b/tests/hp/fe_nothing_05.cc
@@ -43,7 +43,7 @@
 
 
 // Create a mesh with hanging
-// nodes and FEQ/FENothing interfaces
+// nodes and FEQ/FE_Nothing interfaces
 // in several admissible configurations
 // we'd like to check.  In 2D the mesh
 // looks like the following (with 0
diff --git a/tests/hp/fe_nothing_06.cc b/tests/hp/fe_nothing_06.cc
index 1fc6b9beb3..b8b1e7cfa0 100644
--- a/tests/hp/fe_nothing_06.cc
+++ b/tests/hp/fe_nothing_06.cc
@@ -43,7 +43,7 @@
 
 
 // Create a mesh with hanging
-// nodes and FEQ/FENothing interfaces
+// nodes and FEQ/FE_Nothing interfaces
 // in several admissible configurations
 // we'd like to check.  In 2D the mesh
 // looks like the following.
diff --git a/tests/hp/fe_nothing_07.cc b/tests/hp/fe_nothing_07.cc
index d21624b511..64d48aac6e 100644
--- a/tests/hp/fe_nothing_07.cc
+++ b/tests/hp/fe_nothing_07.cc
@@ -16,7 +16,7 @@
 
 // test that FE_Nothing works as intended
 
-// Create a mesh with hanging nodes and FEQ/FENothing interfaces in
+// Create a mesh with hanging nodes and FEQ/FE_Nothing interfaces in
 // several admissible configurations we'd like to check.  In 2D the
 // mesh looks like the following.
 //
diff --git a/tests/hp/fe_nothing_12.cc b/tests/hp/fe_nothing_12.cc
index 4c969c3d21..1b9726a70c 100644
--- a/tests/hp/fe_nothing_12.cc
+++ b/tests/hp/fe_nothing_12.cc
@@ -15,7 +15,7 @@
 
 
 // check the case where the two children on a face with a hanging node
-// have different FENothing structure:
+// have different FE_Nothing structure:
 
 // active_fe_index
 // *-----*--*--*
diff --git a/tests/hp/fe_nothing_13.cc b/tests/hp/fe_nothing_13.cc
index d26e5b11af..dc50bfe062 100644
--- a/tests/hp/fe_nothing_13.cc
+++ b/tests/hp/fe_nothing_13.cc
@@ -15,7 +15,7 @@
 
 
 // check the case where the two children on a face with a hanging node have
-// different FENothing structure. while all cells in the _12 test had degrees
+// different FE_Nothing structure. while all cells in the _12 test had degrees
 // of freedom, here, cells with active_fe_index==1 are simply FE_Nothing:
 
 // active_fe_index
diff --git a/tests/hp/fe_nothing_14.cc b/tests/hp/fe_nothing_14.cc
index f49c2a4b94..b7dfd16f0f 100644
--- a/tests/hp/fe_nothing_14.cc
+++ b/tests/hp/fe_nothing_14.cc
@@ -15,7 +15,7 @@
 
 
 // check the case where the two children on a face with a hanging node have
-// different FENothing structure. compared to _12 and _13, the situation is
+// different FE_Nothing structure. compared to _12 and _13, the situation is
 // even more wicked since in the picture below 0=FE_Q(1), 1=FE_Nothing,
 // 2=FE_Q(2), i.e. 2 dominates 1
 
diff --git a/tests/hp/solution_transfer_03.cc b/tests/hp/solution_transfer_03.cc
index a16279b751..75edf39d6b 100644
--- a/tests/hp/solution_transfer_03.cc
+++ b/tests/hp/solution_transfer_03.cc
@@ -15,7 +15,7 @@
 
 
 // SolutionTransfer got into trouble when interpolating between an old and a
-// new mesh where some cells are set to use FENothing, see bug #83
+// new mesh where some cells are set to use FE_Nothing, see bug #83
 // (https://code.google.com/p/dealii/issues/detail?id=83)
 //
 // the testcase is really invalid -- it forgot to call
diff --git a/tests/mpi/hp_step-4.cc b/tests/mpi/hp_step-4.cc
index c40b4619e1..d985132624 100644
--- a/tests/mpi/hp_step-4.cc
+++ b/tests/mpi/hp_step-4.cc
@@ -16,8 +16,9 @@
 // A lightly adapted version of the step-4 tutorial program. Compared
 // to step-4, this test uses hp::DoFHandler and
 // parallel::distributed::Triangulation. In the upper half of the domain
-// FENothing is used to save effort, as these elements would only be used later.
-// The test checks whether the hanging-node constraints are setup correctly.
+// FE_Nothing is used to save effort, as these elements would only be used
+// later. The test checks whether the hanging-node constraints are setup
+// correctly.
 
 #include <deal.II/base/conditional_ostream.h>
 #include <deal.II/base/function.h>
-- 
2.39.5