From 335bd0893069df60bafe2b19d29618bffd2c9d4e Mon Sep 17 00:00:00 2001
From: Guido Kanschat <dr.guido.kanschat@gmail.com>
Date: Tue, 25 May 2004 12:19:30 +0000
Subject: [PATCH] new local renumbering

git-svn-id: https://svn.dealii.org/trunk@9317 0785d39b-7218-0410-832d-ea1e28bc413d
---
 deal.II/deal.II/include/fe/fe_tools.h | 29 ++++++++++++++++-
 deal.II/deal.II/source/fe/fe_tools.cc | 46 +++++++++++++++++++++++++++
 2 files changed, 74 insertions(+), 1 deletion(-)

diff --git a/deal.II/deal.II/include/fe/fe_tools.h b/deal.II/deal.II/include/fe/fe_tools.h
index 84c9a09058..f08a705684 100644
--- a/deal.II/deal.II/include/fe/fe_tools.h
+++ b/deal.II/deal.II/include/fe/fe_tools.h
@@ -41,11 +41,38 @@ class ConstraintMatrix;
  * $id-I_h$ that is needed for evaluating $(id-I_h)z$ for e.g. the
  * dual solution $z$.
  *
- * @author Ralf Hartmann, 2000
+ * @author Ralf Hartmann, Guido Kanschat, 2000, 2004
  */
 class FETools
 {
   public:
+				     /**
+				      * Compute the vector required to
+				      * renumber the dofs of a cell by
+				      * component. Furthermore,
+				      * compute the vector storing the
+				      * start indices of each
+				      * component in the local block
+				      * vector.
+				      *
+				      * The second vector is organized
+				      * such that there is a vector
+				      * for each base element
+				      * containing the start index for
+				      * each component served by this
+				      * base element.
+				      *
+				      * While the first vector is
+				      * checked to have the correct
+				      * size, the second one is
+				      * reinitialized for convenience.
+				      */
+    template<int dim>
+    static void compute_component_wise(
+      const FiniteElement<dim>&                fe,
+      std::vector<unsigned int>&               renumbering,
+      std::vector<std::vector<unsigned int> >& start_indices);
+    
 				     /**
 				      * Gives the interpolation matrix
 				      * that interpolates a @p fe1-
diff --git a/deal.II/deal.II/source/fe/fe_tools.cc b/deal.II/deal.II/source/fe/fe_tools.cc
index ff26769d58..28eeb32df8 100644
--- a/deal.II/deal.II/source/fe/fe_tools.cc
+++ b/deal.II/deal.II/source/fe/fe_tools.cc
@@ -196,6 +196,47 @@ namespace
   }
 }
 
+template<int dim>
+void FETools::compute_component_wise(
+  const FiniteElement<dim>& element,
+  std::vector<unsigned int>& renumbering,
+  std::vector<std::vector<unsigned int> >& comp_start)
+{
+  Assert(renumbering.size() == element.dofs_per_cell,
+	 ExcDimensionMismatch(renumbering.size(),
+			      element.dofs_per_cell));
+  
+  comp_start.resize(element.n_base_elements());
+  
+  unsigned int k=0;
+  for (unsigned int i=0;i<comp_start.size();++i)
+    {
+      comp_start[i].resize(element.element_multiplicity(i));
+      const unsigned int increment
+	= element.base_element(i).dofs_per_cell;
+      
+      for (unsigned int j=0;j<comp_start[i].size();++j)
+	{
+	  comp_start[i][j] = k;
+	  k += increment;
+	}
+    }
+  
+				   // For each index i of the
+				   // unstructured cellwise
+				   // numbering, renumbering
+				   // contains the index of the
+				   // cell-block numbering
+  for (unsigned int i=0;i<element.dofs_per_cell;++i)
+    {
+      std::pair<std::pair<unsigned int, unsigned int>, unsigned int>
+	indices = element.system_to_base_index(i);
+      renumbering[i] = comp_start[indices.first.first][indices.first.second]
+			     +indices.second;
+    }
+}
+
+
 
 template <int dim, typename number>
 void FETools::get_interpolation_matrix (const FiniteElement<dim> &fe1,
@@ -1539,6 +1580,11 @@ FETools::get_fe_from_name_aux (const std::string &name)
 
 /*-------------- Explicit Instantiations -------------------------------*/
 
+
+template
+void FETools::compute_component_wise(
+  const FiniteElement<deal_II_dimension>& element,
+  std::vector<unsigned int>&, std::vector<std::vector<unsigned int> >&);
 template
 void FETools::get_interpolation_matrix<deal_II_dimension>
 (const FiniteElement<deal_II_dimension> &,
-- 
2.39.5