From 4226ace5e58522b3994f800bcb0297b0da4ccdb7 Mon Sep 17 00:00:00 2001
From: Denis Davydov <davydden@gmail.com>
Date: Mon, 13 Feb 2017 10:00:23 +0100
Subject: [PATCH] FE_Enriched: add prolongation/restriction matrices

---
 include/deal.II/fe/fe_enriched.h | 26 ++++++++++++++++++++++++++
 source/fe/fe_enriched.cc         | 18 ++++++++++++++++++
 2 files changed, 44 insertions(+)

diff --git a/include/deal.II/fe/fe_enriched.h b/include/deal.II/fe/fe_enriched.h
index 5de44ece9f..d983feda8f 100644
--- a/include/deal.II/fe/fe_enriched.h
+++ b/include/deal.II/fe/fe_enriched.h
@@ -316,6 +316,32 @@ public:
   virtual double shape_value(const unsigned int      i,
                              const Point< dim >     &p) const;
 
+  /**
+   * @name Transfer matrices
+   * @{
+   */
+
+  /**
+   * Projection from a fine grid space onto a coarse grid space.
+   *
+   * This function only makes sense when all child elements are also enriched
+   * using the same function(s) as the parent element.
+   */
+  virtual const FullMatrix<double> &
+  get_restriction_matrix (const unsigned int child,
+                          const RefinementCase<dim> &refinement_case=RefinementCase<dim>::isotropic_refinement) const;
+
+  /**
+   * Embedding matrix between grids.
+   *
+   * This function only makes sense when all child elements are also enriched
+   * using the same function(s) as the parent element.
+   */
+  virtual const FullMatrix<double> &
+  get_prolongation_matrix (const unsigned int child,
+                           const RefinementCase<dim> &refinement_case=RefinementCase<dim>::isotropic_refinement) const;
+
+  //@}
 
   /**
    * @name Functions to support hp
diff --git a/source/fe/fe_enriched.cc b/source/fe/fe_enriched.cc
index 405a39d3a8..0962bb99cf 100644
--- a/source/fe/fe_enriched.cc
+++ b/source/fe/fe_enriched.cc
@@ -892,6 +892,24 @@ compare_for_face_domination (const FiniteElement<dim,spacedim> &fe_other) const
     }
 }
 
+template <int dim, int spacedim>
+const FullMatrix<double> &
+FE_Enriched<dim,spacedim>::get_prolongation_matrix (const unsigned int child,
+                                                    const RefinementCase<dim> &refinement_case) const
+{
+  return fe_system.get_prolongation_matrix(child, refinement_case);
+}
+
+
+template <int dim, int spacedim>
+const FullMatrix<double> &
+FE_Enriched<dim,spacedim>::get_restriction_matrix (const unsigned int child,
+                                                   const RefinementCase<dim> &refinement_case) const
+{
+  return fe_system.get_restriction_matrix(child, refinement_case);
+}
+
+
 /* ----------------------- FESystem::InternalData ------------------- */
 
 
-- 
2.39.5