From 31e0804d0a95abebf51fdbd618d2d4f892b3fe1d Mon Sep 17 00:00:00 2001
From: Wolfgang Bangerth <bangerth@math.tamu.edu>
Date: Tue, 19 Apr 2011 00:12:15 +0000
Subject: [PATCH] Compute correct sparsity pattern. Use proper coupling term.
 Copy local contribution into global matrix.

git-svn-id: https://svn.dealii.org/trunk@23608 0785d39b-7218-0410-832d-ea1e28bc413d
---
 deal.II/examples/step-46/step-46.cc | 24 +++++++++++++++---------
 1 file changed, 15 insertions(+), 9 deletions(-)

diff --git a/deal.II/examples/step-46/step-46.cc b/deal.II/examples/step-46/step-46.cc
index 363b7cbcfc..5e093d8e5c 100644
--- a/deal.II/examples/step-46/step-46.cc
+++ b/deal.II/examples/step-46/step-46.cc
@@ -323,7 +323,7 @@ void FluidStructureProblem<dim>::setup_dofs ()
     CompressedSimpleSparsityPattern csp (dof_handler.n_dofs(),
 					 dof_handler.n_dofs());
 
-    DoFTools::make_sparsity_pattern (dof_handler, csp, constraints, false);
+    DoFTools::make_flux_sparsity_pattern (dof_handler, csp, constraints, false);
     sparsity_pattern.copy_from (csp);
   }
 
@@ -505,16 +505,22 @@ void FluidStructureProblem<dim>::assemble_system ()
 
 		      for (unsigned int i=0; i<elasticity_dofs_per_cell; ++i)
 			for (unsigned int j=0; j<stokes_dofs_per_cell; ++j)
-			  local_interface_matrix(i,j) += (2 * viscosity *
-			                                  (stokes_phi_grads_u[j] *
-			                                  normal_vector) *
+			  local_interface_matrix(i,j) += ((2 * viscosity *
+			                                   (stokes_phi_grads_u[j] *
+			                                    normal_vector)
+							   +
+							   stokes_phi_p[j] *
+							   normal_vector) *
 			                                  elasticity_phi[i] *
 			                                  stokes_fe_face_values.JxW(q));
-			  
-			  
-			  neighbor_dof_indices.resize (elasticity_dofs_per_cell);
-			cell->neighbor(f)->get_dof_indices (neighbor_dof_indices);
-		      //constraints.distribute_local_to_global();
+
+
+		      neighbor_dof_indices.resize (elasticity_dofs_per_cell);
+		      cell->neighbor(f)->get_dof_indices (neighbor_dof_indices);
+		      constraints.distribute_local_to_global(local_interface_matrix,
+							     neighbor_dof_indices,
+							     local_dof_indices,
+							     system_matrix);
 		    }
 		}
 	      else if ((cell->neighbor(f)->level() == cell->level())
-- 
2.39.5