From 4c9419041a7d6fb3b4ca323461b4b2f4b2f6bb5f Mon Sep 17 00:00:00 2001
From: Peter Munch <peterrmuench@gmail.com>
Date: Wed, 9 Dec 2020 09:12:33 +0100
Subject: [PATCH] Implement Simplex::FE_Poly::get_constant_modes

---
 include/deal.II/simplex/fe_lib.h |  7 +++++++
 source/simplex/fe_lib.cc         | 12 ++++++++++++
 2 files changed, 19 insertions(+)

diff --git a/include/deal.II/simplex/fe_lib.h b/include/deal.II/simplex/fe_lib.h
index e7c45a8ed9..201620d543 100644
--- a/include/deal.II/simplex/fe_lib.h
+++ b/include/deal.II/simplex/fe_lib.h
@@ -43,6 +43,13 @@ namespace Simplex
     FE_Poly(const unsigned int               degree,
             const std::vector<unsigned int> &dpo_vector);
 
+    /**
+     * Return a list of constant modes of the element. For this element, the
+     * list consists of true arguments for all components.
+     */
+    std::pair<Table<2, bool>, std::vector<unsigned int>>
+    get_constant_modes() const override;
+
   private:
     /**
      * @copydoc dealii::FiniteElement::convert_generalized_support_point_values_to_dof_values()
diff --git a/source/simplex/fe_lib.cc b/source/simplex/fe_lib.cc
index abd6e59042..93fbed41cb 100644
--- a/source/simplex/fe_lib.cc
+++ b/source/simplex/fe_lib.cc
@@ -228,6 +228,18 @@ namespace Simplex
 
 
 
+  template <int dim, int spacedim>
+  std::pair<Table<2, bool>, std::vector<unsigned int>>
+  FE_Poly<dim, spacedim>::get_constant_modes() const
+  {
+    Table<2, bool> constant_modes(1, this->n_dofs_per_cell());
+    constant_modes.fill(true);
+    return std::pair<Table<2, bool>, std::vector<unsigned int>>(
+      constant_modes, std::vector<unsigned int>(1, 0));
+  }
+
+
+
   template <int dim, int spacedim>
   void
   FE_Poly<dim, spacedim>::
-- 
2.39.5