From c62fe2f41c8a5bed306d3a61e1bc9202d50d51a9 Mon Sep 17 00:00:00 2001
From: guido <guido@0785d39b-7218-0410-832d-ea1e28bc413d>
Date: Thu, 7 Dec 2000 10:42:19 +0000
Subject: [PATCH] Krylov-space methods do not use residual() anymore

git-svn-id: https://svn.dealii.org/trunk@3527 0785d39b-7218-0410-832d-ea1e28bc413d
---
 deal.II/lac/include/lac/solver_bicgstab.h | 10 ++++++++--
 deal.II/lac/include/lac/solver_cg.h       |  7 +++++--
 deal.II/lac/include/lac/solver_gmres.h    |  6 ++++--
 deal.II/lac/include/lac/solver_qmrs.h     | 10 ++++++++--
 4 files changed, 25 insertions(+), 8 deletions(-)

diff --git a/deal.II/lac/include/lac/solver_bicgstab.h b/deal.II/lac/include/lac/solver_bicgstab.h
index ed2a1fcbe6..c01f19051b 100644
--- a/deal.II/lac/include/lac/solver_bicgstab.h
+++ b/deal.II/lac/include/lac/solver_bicgstab.h
@@ -241,7 +241,10 @@ template <class MATRIX>
 double
 SolverBicgstab<VECTOR>::criterion (const MATRIX& A, const VECTOR& x, const VECTOR& b)
 {
-  res = A.residual(*Vt, x, b);
+  A.vmult(*Vt, x);
+  Vt->sadd(-1.,1.,b);
+  res = Vt->l2_norm();
+  
   return res;
 }
 
@@ -252,7 +255,10 @@ template <class MATRIX>
 SolverControl::State
 SolverBicgstab<VECTOR>::start(const MATRIX& A)
 {
-  res = A.residual(*Vr, *Vx, *Vb);
+  A.vmult(*Vr, *Vx);
+  Vr->sadd(-1.,1.,*Vb);
+  res = Vr->l2_norm();
+  
   Vp->reinit(*Vx);
   Vv->reinit(*Vx);
   Vrbar->equ(1.,*Vr);
diff --git a/deal.II/lac/include/lac/solver_cg.h b/deal.II/lac/include/lac/solver_cg.h
index 5ebb3e822e..d6c8aeae32 100644
--- a/deal.II/lac/include/lac/solver_cg.h
+++ b/deal.II/lac/include/lac/solver_cg.h
@@ -199,8 +199,11 @@ SolverCG<VECTOR>::solve (const MATRIX &A,
 				   // library
   int  it=0;
   double res,gh,alpha,beta;
- 
-  res = A.residual(g,x,b);
+
+  A.vmult(g,x);
+  g.sadd(-1.,1.,b);
+  res = g.l2_norm();
+  
   conv = control().check(0,res);
   if (conv) 
     {
diff --git a/deal.II/lac/include/lac/solver_gmres.h b/deal.II/lac/include/lac/solver_gmres.h
index 23e5e190b1..fd77abd2a5 100644
--- a/deal.II/lac/include/lac/solver_gmres.h
+++ b/deal.II/lac/include/lac/solver_gmres.h
@@ -279,10 +279,12 @@ unsigned int dim = 0;
       
       if (left_precondition)
 	{
-	  A.residual(p,x,b);
+	  A.vmult(p,x);
+	  p.sadd(-1.,1.,b);
 	  precondition.vmult(v,p);
 	} else {
-	  A.residual(v,x,b);
+	  A.vmult(v,x);
+	  v.sadd(-1.,1.,b);
 	};
  
       double rho = v.l2_norm();
diff --git a/deal.II/lac/include/lac/solver_qmrs.h b/deal.II/lac/include/lac/solver_qmrs.h
index 81a2ac359f..3376d6263f 100644
--- a/deal.II/lac/include/lac/solver_qmrs.h
+++ b/deal.II/lac/include/lac/solver_qmrs.h
@@ -304,7 +304,9 @@ SolverQMRS<VECTOR>::iterate(const MATRIX& A,
 				   // Apply right preconditioning to x
   precondition.vmult(q,x);  
 				   // Preconditioned residual
-  res = A.residual(v, q, b);
+  A.vmult(v,q);
+  v.sadd(-1.,1.,b);
+  res = v.l2_norm();
 
   if (control().check(step, res) == SolverControl::success)
     return success;
@@ -352,7 +354,11 @@ while (state == SolverControl::iterate)
       print_vectors(step,x,v,d);
 				       // Step 5
       if (additional_data.exact_residual)
-	res = A.residual(q,x,b);
+	{
+	  A.vmult(q,x);
+	  q.sadd(-1.,1.,b);
+	  res = q.l2_norm();
+	}
       else
 	res = sqrt((it+1)*tau);
       state = control().check(step,res);
-- 
2.39.5