From 5bb2f788ebcce0697463aedad401c5a2da59e63d Mon Sep 17 00:00:00 2001
From: Wolfgang Bangerth <bangerth@colostate.edu>
Date: Fri, 9 Jun 2023 15:50:47 -0600
Subject: [PATCH] Clarify the name of a variable.

While there, also update some documentation.
---
 include/deal.II/fe/fe_data.h | 22 +++++++++++++---------
 source/fe/fe_data.cc         |  2 +-
 2 files changed, 14 insertions(+), 10 deletions(-)

diff --git a/include/deal.II/fe/fe_data.h b/include/deal.II/fe/fe_data.h
index 3689d511d6..2ecbf3b37e 100644
--- a/include/deal.II/fe/fe_data.h
+++ b/include/deal.II/fe/fe_data.h
@@ -140,8 +140,11 @@ namespace internal
   /**
    * Internal data structure for setting up FiniteElementData. It stores for
    * each object the (inclusive/exclusive) number of degrees of freedoms, as
-   * well as, the index of its first degree of freedom within a cell and the
-   * index of the first d-dimensional object within each face.
+   * well as the index of its first degree of freedom within a cell and the
+   * index of the first d-dimensional object within each face. Here, inclusive
+   * means "the number of DoFs located on this object as well as the
+   * lower-dimensional objects that bound it", and exclusive is then the
+   * number not including the lower-dimensional objects.
    *
    * The information is saved as a vector of vectors. One can query the
    * inclusive number of dofs of the i-th d-dimensional object via:
@@ -156,15 +159,15 @@ namespace internal
    * obj_index 0 1 2 3 4 5 | 6 7 8 9 10 11 12 13 14 | 15 15 15 16 17 | 18
    * @endcode
    *
-   * Since the above table looks as follows for:
+   * The above table has these numbers because of the following considerations:
    *
-   * - a triangle:
+   * - For each triangular face:
    * @code
    * dpo_excl  1  1  1 | 1  1  1 |  0
    * obj_index 0  1  2 | 3  4  5 |  6
    * @endcode
    *
-   * - quadrilateral:
+   * - For each quadrilateral face:
    * @code
    * dpo_excl  1  1  1  1 | 1  1  1  1 |  1
    * obj_index 0  1  2  3 | 4  5  6  7 |  8
@@ -305,10 +308,11 @@ private:
   const ReferenceCell reference_cell_kind;
 
   /**
-   * Number of unique quads. If all quads have the same type, the value is
-   * one; else it equals the number of quads.
+   * Number of unique two-dimensional sub-objects. If all
+   * two-dimensional sub-objects have the same type, the value is one;
+   * else it equals the number of quads.
    */
-  const unsigned int number_unique_quads;
+  const unsigned int number_of_unique_2d_subobjects;
 
   /**
    * Number of unique faces. If all faces have the same type, the value is
@@ -772,7 +776,7 @@ template <int dim>
 inline unsigned int
 FiniteElementData<dim>::n_unique_quads() const
 {
-  return number_unique_quads;
+  return number_of_unique_2d_subobjects;
 }
 
 
diff --git a/source/fe/fe_data.cc b/source/fe/fe_data.cc
index 98b9cd8f2f..032b3ba080 100644
--- a/source/fe/fe_data.cc
+++ b/source/fe/fe_data.cc
@@ -157,7 +157,7 @@ FiniteElementData<dim>::FiniteElementData(
   const Conformity                      conformity,
   const BlockIndices &                  block_indices)
   : reference_cell_kind(reference_cell)
-  , number_unique_quads(
+  , number_of_unique_2d_subobjects(
       internal::number_unique_entries(data.dofs_per_object_inclusive[2]))
   , number_unique_faces(
       internal::number_unique_entries(data.dofs_per_object_inclusive[dim - 1]))
-- 
2.39.5