numcxx::TPreconILU< T > Class Template Reference

Description

template<typename T>
class numcxx::TPreconILU< T >

ILU preconditioner class.

Definition at line 16 of file tprecon-ilu.hxx.

Inheritance diagram for numcxx::TPreconILU< T >:

Collaboration diagram for numcxx::TPreconILU< T >:

Public Member Functions
	TPreconILU (const std::shared_ptr< TSparseMatrix< T >> pA)
	Create Preconditioner. More...
	TPreconILU (TSparseMatrix< T > &A)
	~TPreconILU ()
void	update (TSparseMatrix< T > &A)
	Perform actual computation preconditioner. More...
void	solve (TArray< T > &Sol, const TArray< T > &Rhs) const
	Solve preconditioning system. More...
virtual void	update (void)

Static Public Member Functions
static std::shared_ptr< TPreconILU< T > >	create (const std::shared_ptr< TSparseMatrix< T >> pA)
	Create preconditioner. More...

Public Attributes
std::shared_ptr< TArray1< T > >	pInvDiag
std::shared_ptr< TArray1< int > >	pDiagIdx

Private Attributes
std::shared_ptr< TArray1< T > >	pA
std::shared_ptr< TArray1< int > >	pIA
std::shared_ptr< TArray1< int > >	pJA

Constructor & Destructor Documentation

template<typename T >

numcxx::TPreconILU< T >::TPreconILU ( const std::shared_ptr< TSparseMatrix< T >>  pA )

inline

Create Preconditioner.

Definition at line 7 of file tprecon-ilu.ixx.

  {
    pInvDiag=std::make_shared<TArray1<T>>(pMatrix->shape(0));
    pDiagIdx=std::make_shared<TArray1<int>>(pMatrix.shape(0));
    update(*pMatrix);
  }

template<typename T >

numcxx::TPreconILU< T >::TPreconILU ( TSparseMatrix< T > &  A )

inline

Definition at line 15 of file tprecon-ilu.ixx.

  {
    pInvDiag=std::make_shared<TArray1<T>>(A.shape(0));
    pDiagIdx=std::make_shared<TArray1<int>>(A.shape(0));
    update(A);
  }

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template<typename T >

numcxx::TPreconILU< T >::~TPreconILU ( )

inline

Definition at line 27 of file tprecon-ilu.hxx.

{};

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Member Function Documentation

template<typename T >

std::shared_ptr< TPreconILU< T > > numcxx::TPreconILU< T >::create ( const std::shared_ptr< TSparseMatrix< T >>  pA )

inlinestatic

Create preconditioner.

Definition at line 24 of file tprecon-ilu.ixx.

  {
    return std::make_shared<TPreconILU<T>>(pA);
  }

template<typename T >

void numcxx::TPreconILU< T >::update ( TSparseMatrix< T > &  A )

inline

Perform actual computation preconditioner.

Perform actual computation of LU factorization.

Definition at line 31 of file tprecon-ilu.ixx.

  {

    int n=M.shape(0);
    pA=M.pA;
    pIA=M.pIA;
    pJA=M.pJA;

    auto & A=*pA;
    auto & IA=*pIA;
    auto & JA=*pJA;
    auto & XD=*pInvDiag;
    auto & ID=*pDiagIdx;

    for (int i=0; i<n; i++)
    {
      for (int j=IA(i);j<IA(i+1);j++)
        if (JA(j)==i)
        {
          ID(i)=j;
          break;
        }
      XD(i)=A(ID(i));
    }
    
    for (int i=0; i<n; i++)
    {
      XD(i)=1.0/XD(i);
      for(int j=ID(i)+1;j<IA(i+1);j++)
      {
        int k;
        bool found=false;
        for(k=IA(JA(j));k<IA(JA(j)+1);k++)
        {
          if (JA(k)==i)
          {
            found=true;
            break;
          }
        }
        if (found) XD(JA(j))-=A(k)*XD(i)*A(j);
      }
    }

   M.pattern_changed(false);
  }

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template<typename T >

void numcxx::TPreconILU< T >::solve ( TArray< T > &  Sol, const TArray< T > &  Rhs  ) const

inlinevirtual

Solve preconditioning system.

Solve LU factorized system.

Reimplemented from numcxx::TLinSolver< T >.

Definition at line 80 of file tprecon-ilu.ixx.

  {
    int n=pIA->size()-1;
    auto & A=*pA;
    auto & IA=*pIA;
    auto & JA=*pJA;
    auto & XD=*pInvDiag;
    auto & ID=*pDiagIdx;

    Sol.resize(Rhs.size());
    for (int i=0; i<n; i++)
    {
      T x=0.0;
      for(int j=IA(i);j<ID(i);j++)
        x+=A(j)*Sol(JA(j));
      Sol(i)=XD(i)*(Rhs(i)-x);
    }

    for (int i=n-1; i>=0; i--)
    {
      T x=0.0;
      for(int j=ID(i)+1;j<IA(i+1);j++)
        x += Sol(JA(j))*A(j);
      Sol(i)-=x*XD(i);
    }
  }

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template<typename T >

virtual void numcxx::TLinSolver< T >::update ( void  )

inlinevirtualinherited

Reimplemented in numcxx::TSolverUMFPACK< T >, and numcxx::TSolverLapackLU< T >.

Definition at line 280 of file tarray.hxx.

{};

Member Data Documentation

template<typename T >

std::shared_ptr< TArray1<T> > numcxx::TPreconILU< T >::pInvDiag

Definition at line 20 of file tprecon-ilu.hxx.

template<typename T >

std::shared_ptr< TArray1<int> > numcxx::TPreconILU< T >::pDiagIdx

Definition at line 21 of file tprecon-ilu.hxx.

template<typename T >

std::shared_ptr<TArray1<T> > numcxx::TPreconILU< T >::pA

private

Definition at line 39 of file tprecon-ilu.hxx.

template<typename T >

std::shared_ptr<TArray1<int> > numcxx::TPreconILU< T >::pIA

private

Definition at line 40 of file tprecon-ilu.hxx.

template<typename T >

std::shared_ptr<TArray1<int> > numcxx::TPreconILU< T >::pJA

private

Definition at line 41 of file tprecon-ilu.hxx.

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The documentation for this class was generated from the following files:

• tprecon-ilu.hxx
• tprecon-ilu.ixx