Commit a220cfb4 authored by Jakub Klinkovský's avatar Jakub Klinkovský
Browse files

Fixed and optimized the CG solver

parent 30b25f63

src/TNL/Solvers/Linear/CG_impl.h

+14 −16
Original line number Original line Diff line number Diff line
@@ -12,8 +12,6 @@ 




#include "CG.h"

#include "CG.h"





#include <TNL/Solvers/Linear/LinearResidueGetter.h>



namespace TNL {

namespace TNL {

namespace Solvers {

namespace Solvers {

namespace Linear {

namespace Linear {
@@ -32,9 +30,7 @@ CG< Matrix >:: 
solve( ConstVectorViewType b, VectorViewType x )

solve( ConstVectorViewType b, VectorViewType x )

{

{

   this->setSize( this->matrix->getRows() );

   this->setSize( this->matrix->getRows() );



   this->resetIterations();

   this->resetIterations();

   this->setResidue( this->getConvergenceResidue() + 1.0 );





   RealType alpha, beta, s1, s2;

   RealType alpha, beta, s1, s2;

   RealType bNorm = b.lpNorm( ( RealType ) 2.0 );

   RealType bNorm = b.lpNorm( ( RealType ) 2.0 );
@@ -46,20 +42,23 @@ solve( ConstVectorViewType b, VectorViewType x ) 
   r.addVector( b, 1.0, -1.0 );

   r.addVector( b, 1.0, -1.0 );

   p = r;

   p = r;





   s1 = r.scalarProduct( r );

   // TODO

   //this->setResidue( std::sqrt(s1) / bNorm );

   this->setResidue( std::sqrt(s1) );



   while( this->nextIteration() )

   while( this->nextIteration() )

   {

   {

      /****

      /****

       * 1. alpha_j = ( r_j, r_j ) / ( A * p_j, p_j )

       * 1. alpha_j = ( r_j, r_j ) / ( A * p_j, p_j )

       */

       */

      this->matrix->vectorProduct( p, Ap );

      this->matrix->vectorProduct( p, Ap );



      s1 = r.scalarProduct( r );

      s2 = Ap.scalarProduct( p );

      s2 = Ap.scalarProduct( p );





      /****

      /****

       * if s2 = 0 => p = 0 => r = 0 => we have the solution (provided A != 0)

       * if s2 = 0 => p = 0 => r = 0 => we have the solution (provided A != 0)

       */

       */

      if( s2 == 0.0 ) alpha = 0.0;

      if( s2 == 0.0 ) break;

      else alpha = s1 / s2;

      else alpha = s1 / s2;





      /****

      /****
@@ -70,14 +69,13 @@ solve( ConstVectorViewType b, VectorViewType x ) 
      /****

      /****

       * 3. r_{j+1} = r_j - \alpha_j A * p_j

       * 3. r_{j+1} = r_j - \alpha_j A * p_j

       */

       */

      new_r = r;

      new_r.addVectors( r, 1, Ap, -alpha, 0 );

      new_r.addVector( Ap, -alpha );





      /****

      /****

       * 4. beta_j = ( r_{j+1}, r_{j+1} ) / ( r_j, r_j )

       * 4. beta_j = ( r_{j+1}, r_{j+1} ) / ( r_j, r_j )

       */

       */

      s2 = s1;

      s1 = new_r.scalarProduct( new_r );

      s1 = new_r.scalarProduct( new_r );

      s2 = r. scalarProduct( r );





      /****

      /****

       * if s2 = 0 => r = 0 => we have the solution

       * if s2 = 0 => r = 0 => we have the solution
@@ -95,10 +93,10 @@ solve( ConstVectorViewType b, VectorViewType x ) 
       */

       */

      new_r.swap( r );

      new_r.swap( r );





      if( this->getIterations() % 10 == 0 )

      // TODO

         this->setResidue( LinearResidueGetter::getResidue( *this->matrix, x, b, bNorm ) );

      //this->setResidue( std::sqrt(s1) / bNorm );

      this->setResidue( std::sqrt(s1) );

   }

   }

   this->setResidue( LinearResidueGetter::getResidue( *this->matrix, x, b, bNorm ) );

   this->refreshSolverMonitor( true );

   this->refreshSolverMonitor( true );

   return this->checkConvergence();

   return this->checkConvergence();

}

}