BCond.h

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// -*- C++ -*-
/***************************************************************************
 *
 * The IPPL Framework
 *
 ***************************************************************************/

#ifndef BCOND_H
#define BCOND_H

#include "Utility/IpplInfo.h"
#include "Utility/RefCounted.h"
#include "Utility/vmap.h"

#include <iostream>
#include <complex>

// forward declarations
template <unsigned D> class NDIndex;
template <class T, unsigned D> class Vektor;
template <class T, unsigned D> class Tenzor;
template <class T, unsigned D> class SymTenzor;
template <class T, unsigned D> class AntiSymTenzor;
template<unsigned D, class T> class UniformCartesian;
template<class T, unsigned D> class LField;
template<class T, unsigned D> class BareField;
template<class T, unsigned D, class M, class C> class Field;
template <class T, unsigned D, class M, class C> class BCondBase;
template <class T, unsigned D, class M, class C>
std::ostream& operator<<(std::ostream&, const BCondBase<T,D,M,C>&);
template <class T, unsigned D, class M, class C> class BConds;
template <class T, unsigned D, class M, class C>
std::ostream& operator<<(std::ostream&, const BConds<T,D,M,C>&);


//
// Traits used by the single-component version of the applicative templates.
// General case: this covers intrinsic types like double, bool automatically:
//

template<class T>
struct ApplyToComponentType 
{
  typedef T type;
};

//
// Specializations for multicomponent IPPL types;
//
template<class T,unsigned D>
struct ApplyToComponentType< Vektor<T,D> > 
{
  typedef T type;
};

template<class T,unsigned D>
struct ApplyToComponentType< Tenzor<T,D> > 
{
  typedef T type;
};

template<class T,unsigned D>
struct ApplyToComponentType< SymTenzor<T,D> > 
{
  typedef T type;
};

template<class T,unsigned D>
struct ApplyToComponentType< AntiSymTenzor<T,D> > 
{
  typedef T type;
};

// Helper classes for getting info about number of indices into 
// BCond-class ctor functions.
// Define tag types (like iterator tags in stl):

class scalar_tag
{
};

class vektor_tag
{
};

class tenzor_tag
{
};

class symtenzor_tag
{
};

class antisymtenzor_tag
{
};

// Implement tag types for intrinsic types:
inline scalar_tag get_tag(std::complex<double>) { return scalar_tag(); }
inline scalar_tag get_tag(double)   { return scalar_tag(); }
inline scalar_tag get_tag(float)    { return scalar_tag(); }
inline scalar_tag get_tag(int)      { return scalar_tag(); }
inline scalar_tag get_tag(bool)     { return scalar_tag(); }
inline scalar_tag get_tag(short)    { return scalar_tag(); }

// Tag for Vektor types:
template<class T, unsigned D>
inline vektor_tag 
get_tag(Vektor<T,D>) { return vektor_tag(); }

// Tag for Tenzor types:
template<class T, unsigned D>
inline tenzor_tag 
get_tag(Tenzor<T,D>) { return tenzor_tag(); }

// Tag for AntiSymTenzor types
template<class T, unsigned D>
inline antisymtenzor_tag 
get_tag(AntiSymTenzor<T,D>) { return antisymtenzor_tag(); }

// Tag for SymTenzor types
template<class T, unsigned D>
inline symtenzor_tag 
get_tag(SymTenzor<T,D>) { return symtenzor_tag(); }

// Functions which return an enum value indicating scalar, vector, tensor,
// or anti/symtensor type; used in constructors for PeriodicFace, etc., to
// determine how to turn two 1D component indices into a single index value
// for pointer offsetting into the Tenzor/Anti/SymTenzor object:
enum TensorOrder_e { IPPL_SCALAR=0, IPPL_VECTOR=1, IPPL_TENSOR=2, 
                     IPPL_SYMTENSOR=3, IPPL_ANTISYMTENSOR=4 } ;
inline TensorOrder_e getTensorOrder(const scalar_tag& )
{return IPPL_SCALAR;}
inline TensorOrder_e getTensorOrder(const vektor_tag& )
{return IPPL_VECTOR;}
inline TensorOrder_e getTensorOrder(const tenzor_tag& )
{return IPPL_TENSOR;}
inline TensorOrder_e getTensorOrder(const antisymtenzor_tag& )
{return IPPL_ANTISYMTENSOR;}
inline TensorOrder_e getTensorOrder(const symtenzor_tag& )
{return IPPL_SYMTENSOR;}


template<class T, unsigned D, class M, class C>
class BCondBase : public RefCounted
{
public:

  // Special value designating application to all components of elements:
  static int allComponents;

  // Constructor takes:
  // face: the face to apply the boundary condition on.
  // i,j : what component of T to apply the boundary condition to.
  // The components default to setting all components.
  BCondBase(unsigned int face,
            int i = allComponents,
            int j = allComponents);
  virtual ~BCondBase() { }

  virtual void apply( Field<T,D,M,C>& ) = 0;
  virtual BCondBase<T,D,M,C>* clone() const = 0;

  virtual void write(std::ostream&) const;

  // Return component of Field element on which BC applies
  int getComponent() const { return m_component; }

  // Return face on which BC applies
  unsigned int getFace() const { return m_face; }

  // Returns whether or not this BC changes physical cells.
  bool changesPhysicalCells() const { return m_changePhysical; }

protected:

  // Following are hooks for BC-by-Field-element-component support:
  // Component of Field elements (Vektor, e.g.) on which the BC applies:
  int m_component;
  
  // What face to apply the boundary condition to.
  unsigned int m_face;

  // True if this boundary condition changes physical cells.
  bool m_changePhysical;
};


template<
  class T,
  unsigned D,
  class M=UniformCartesian<D,double>,
  class C=typename M::DefaultCentering>
class BConds
  : public vmap<int, RefCountedP< BCondBase<T,D,M,C> > >
{
public: 
  typedef typename vmap<int, RefCountedP <BCondBase<T,D,M,C> > >::iterator 
    iterator; 
  typedef typename vmap<int, RefCountedP <BCondBase<T,D,M,C> > >::const_iterator 
    const_iterator; 
  void apply( Field<T,D,M,C>& a );
  bool changesPhysicalCells() const;
  virtual void write(std::ostream&) const;
};


// TJW: so far, componentwise specification of BCondNoAction not possible

template<class T,
         unsigned D, 
         class M=UniformCartesian<D,double>, 
         class C=typename M::DefaultCentering>
class BCondNoAction : public BCondBase<T,D,M,C>
{
public:
  BCondNoAction(int face) : BCondBase<T,D,M,C>(face) {}

  virtual void apply( Field<T,D,M,C>& ) {}
  BCondBase<T,D,M,C>* clone() const
  {
    return new BCondNoAction<T,D,M,C>( *this );
  }

  // Print out information about the BC to a stream.
  virtual void write(std::ostream& out) const;
};


template<class T,
         unsigned D, 
         class M=UniformCartesian<D,double>, 
         class C=typename M::DefaultCentering>
class PeriodicFace : public BCondBase<T,D,M,C>
{
public:
  // Constructor takes zero, one, or two int's specifying components of 
  // multicomponent types like Vektor/Tenzor/Anti/SymTenzor this BC applies to.
  // Zero int's specified means apply to all components; one means apply to
  // component (i), and two means apply to component (i,j),
  typedef BCondBase<T,D,M,C> BCondBaseTDMC;

  PeriodicFace(unsigned f, 
               int i = BCondBaseTDMC::allComponents,
               int j = BCondBaseTDMC::allComponents);

  // Apply the boundary condition to a particular Field.
  virtual void apply( Field<T,D,M,C>& );

  // Make a copy of the concrete type.
  virtual BCondBase<T,D,M,C>* clone() const
  {
    return new PeriodicFace<T,D,M,C>( *this );
  }

  // Print out information about the BC to a stream.
  virtual void write(std::ostream& out) const;
};



//BENI adds Periodic Boundary Conditions for Interpolations///////////
template<class T,
         unsigned D,
         class M=UniformCartesian<D,double>,
         class C=typename M::DefaultCentering>
class InterpolationFace : public BCondBase<T,D,M,C>
{
public:
  // Constructor takes zero, one, or two int's specifying components of
  // multicomponent types like Vektor/Tenzor/Anti/SymTenzor this BC applies to.
  // Zero int's specified means apply to all components; one means apply to
  // component (i), and two means apply to component (i,j),
  typedef BCondBase<T,D,M,C> BCondBaseTDMC;

  InterpolationFace(unsigned f,
               int i = BCondBaseTDMC::allComponents,
               int j = BCondBaseTDMC::allComponents);

  // Apply the boundary condition to a particular Field.
  virtual void apply( Field<T,D,M,C>& );

  // Make a copy of the concrete type.
  virtual BCondBase<T,D,M,C>* clone() const
  {
    return new InterpolationFace<T,D,M,C>( *this );
  }

  // Print out information about the BC to a stream.
  virtual void write(std::ostream& out) const;
};


template<class T, unsigned D, 
         class M=UniformCartesian<D,double>, 
         class C=typename M::DefaultCentering>
class ParallelPeriodicFace : public PeriodicFace<T,D,M,C>
{
public:

  // Constructor takes zero, one, or two int's specifying components
  // of multicomponent types like Vektor/Tenzor/AntiTenzor/SymTenzor
  // this BC applies to.  Zero int's means apply to all components;
  // one means apply to component (i), and two means apply to
  // component (i,j),

  typedef BCondBase<T,D,M,C> Base_t;

  ParallelPeriodicFace(unsigned f, 
                       int i = Base_t::allComponents,
                       int j = Base_t::allComponents)
    : PeriodicFace<T,D,M,C>(f,i,j) 
  { }

  // Apply the boundary condition to a particular Field.

  virtual void apply( Field<T,D,M,C>& );

  // Make a copy of the concrete type.

  virtual Base_t * clone() const
  {
    return new ParallelPeriodicFace<T,D,M,C>( *this );
  }

  // Print out information about the BC to a stream.

  virtual void write(std::ostream& out) const;
};



// BENI adds parallel Interpolation Face

template<class T, unsigned D,
         class M=UniformCartesian<D,double>,
         class C=typename M::DefaultCentering>
class ParallelInterpolationFace : public InterpolationFace<T,D,M,C>
{
public:

  // Constructor takes zero, one, or two int's specifying components
  // of multicomponent types like Vektor/Tenzor/AntiTenzor/SymTenzor
  // this BC applies to.  Zero int's means apply to all components;
  // one means apply to component (i), and two means apply to
  // component (i,j),

  typedef BCondBase<T,D,M,C> Base_t;

  ParallelInterpolationFace(unsigned f,
                       int i = Base_t::allComponents,
                       int j = Base_t::allComponents)
    : InterpolationFace<T,D,M,C>(f,i,j)
  { }

  // Apply the boundary condition to a particular Field.

  virtual void apply( Field<T,D,M,C>& );

  // Make a copy of the concrete type.

  virtual Base_t * clone() const
  {
    return new ParallelInterpolationFace<T,D,M,C>( *this );
  }

  // Print out information about the BC to a stream.

  virtual void write(std::ostream& out) const;
};



template<class T,
         unsigned D, 
         class M=UniformCartesian<D,double>, 
         class C=typename M::DefaultCentering>
class ExtrapolateFace : public BCondBase<T,D,M,C>
{
public:
  // Constructor takes zero, one, or two int's specifying components of 
  // multicomponent types like Vektor/Tenzor/Anti/SymTenzor this BC applies to.
  // Zero int's specified means apply to all components; one means apply to
  // component (i), and two means apply to component (i,j),
  typedef BCondBase<T,D,M,C> BCondBaseTDMC;
  ExtrapolateFace(unsigned f, T o, T s, 
                  int i = BCondBaseTDMC::allComponents,
                  int j = BCondBaseTDMC::allComponents);

  // Apply the boundary condition to a given Field.
  virtual void apply( Field<T,D,M,C>& );

  // Make a copy of the concrete type.
  virtual BCondBase<T,D,M,C>* clone() const
  {
    return new ExtrapolateFace<T,D,M,C>( *this );
  }

  // Print out some information about the BC to a given stream.
  virtual void write(std::ostream&) const;

  const T& getOffset() const { return Offset; }
  const T& getSlope() const { return Slope; }

protected:
  T Offset, Slope;
};



// TJW added 12/16/1997 as per Tecolote team's request: this one sets last
// physical element layer to zero for vert-centered elements/components. For
// cell-centered, doesn't need to do this because the zero point of an odd
// function is halfway between the last physical element and the first guard
// element.

template<class T,
         unsigned D, 
         class M=UniformCartesian<D,double>, 
         class C=typename M::DefaultCentering>
class ExtrapolateAndZeroFace : public BCondBase<T,D,M,C>
{
public:
  // Constructor takes zero, one, or two int's specifying components of 
  // multicomponent types like Vektor/Tenzor/Anti/SymTenzor this BC applies to.
  // Zero int's specified means apply to all components; one means apply to
  // component (i), and two means apply to component (i,j),
  typedef BCondBase<T,D,M,C> BCondBaseTDMC;
  ExtrapolateAndZeroFace(unsigned f, T o, T s, 
                  int i = BCondBaseTDMC::allComponents,
                  int j = BCondBaseTDMC::allComponents);

  // Apply the boundary condition to a given Field.
  virtual void apply( Field<T,D,M,C>& );

  // Make a copy of the concrete type.
  virtual BCondBase<T,D,M,C>* clone() const
  {
    return new ExtrapolateAndZeroFace<T,D,M,C>( *this );
  }

  // Print out some information about the BC to a given stream.
  virtual void write(std::ostream&) const;

  const T& getOffset() const { return Offset; }
  const T& getSlope() const { return Slope; }

protected:
  T Offset, Slope;
};



template<class T,
         unsigned D, 
         class M=UniformCartesian<D,double>, 
         class C=typename M::DefaultCentering>
class PosReflectFace : public ExtrapolateFace<T,D,M,C>
{
public: 
  typedef BCondBase<T,D,M,C> BCondBaseTDMC;
  PosReflectFace(unsigned f,
                 int i = BCondBaseTDMC::allComponents,
                 int j = BCondBaseTDMC::allComponents)
    : ExtrapolateFace<T,D,M,C>(f,0,1,i,j) {}

  // Print out information about the BC to a stream.
  virtual void write(std::ostream& out) const;
};


template<class T,
         unsigned D, 
         class M=UniformCartesian<D,double>, 
         class C=typename M::DefaultCentering>
class NegReflectFace : public ExtrapolateFace<T,D,M,C>
{
public: 
  typedef BCondBase<T,D,M,C> BCondBaseTDMC;
  NegReflectFace(unsigned f,
                 int i = BCondBaseTDMC::allComponents,
                 int j = BCondBaseTDMC::allComponents)
    : ExtrapolateFace<T,D,M,C>(f,0,-1,i,j) {}

  // Print out information about the BC to a stream.
  virtual void write(std::ostream& out) const;
};


// TJW added 12/16/1997 as per Tecolote team's request: this one sets last
// physical element layer to zero for vert-centered elements/components. For
// cell-centered, doesn't need to do this because the zero point of an odd
// function is halfway between the last physical element and the first guard
// element.

template<class T,
         unsigned D, 
         class M=UniformCartesian<D,double>, 
         class C=typename M::DefaultCentering>
class NegReflectAndZeroFace : public ExtrapolateAndZeroFace<T,D,M,C>
{
public: 
  typedef BCondBase<T,D,M,C> BCondBaseTDMC;
  NegReflectAndZeroFace(unsigned f,
                        int i = BCondBaseTDMC::allComponents,
                        int j = BCondBaseTDMC::allComponents)
    : ExtrapolateAndZeroFace<T,D,M,C>(f,0,-1,i,j) {}

  // Print out information about the BC to a stream.
  virtual void write(std::ostream& out) const;
};


template<class T,
         unsigned D, 
         class M=UniformCartesian<D,double>, 
         class C=typename M::DefaultCentering>
class ConstantFace : public ExtrapolateFace<T,D,M,C>
{
public: 
  typedef BCondBase<T,D,M,C> BCondBaseTDMC;
  ConstantFace(unsigned f, T c,
               int i = BCondBaseTDMC::allComponents,
               int j = BCondBaseTDMC::allComponents)
    : ExtrapolateFace<T,D,M,C>(f,c,0,i,j) {}

  // Print out information about the BC to a stream.
  virtual void write(std::ostream& out) const;
};


template<class T,
         unsigned D, 
         class M=UniformCartesian<D,double>, 
         class C=typename M::DefaultCentering>
class ZeroFace : public ExtrapolateFace<T,D,M,C>
{
public: 
  typedef BCondBase<T,D,M,C> BCondBaseTDMC;
  ZeroFace(unsigned f,
           int i = BCondBaseTDMC::allComponents,
           int j = BCondBaseTDMC::allComponents)
    : ExtrapolateFace<T,D,M,C>(f,0,0,i,j) {}

  // Print out information about the BC to a stream.
  virtual void write(std::ostream& out) const;
};


// TJW added 1/25/1998 as per Blanca's (Don Marshal's, for the Lagrangian
// code) request: this one sets last physical element layer to zero for
// vert-centered elements/components. For cell-centered, doesn't need to do
// this because the zero point of an odd function is halfway between the last
// physical element and the first guard element.

template<class T,
         unsigned D, 
         class M=UniformCartesian<D,double>, 
         class C=typename M::DefaultCentering>
class ZeroGuardsAndZeroFace : public ExtrapolateAndZeroFace<T,D,M,C>
{
public: 
  typedef BCondBase<T,D,M,C> BCondBaseTDMC;
  ZeroGuardsAndZeroFace(unsigned f,
                        int i = BCondBaseTDMC::allComponents,
                        int j = BCondBaseTDMC::allComponents)
    : ExtrapolateAndZeroFace<T,D,M,C>(f,0,0,i,j) {}

  // Print out information about the BC to a stream.
  virtual void write(std::ostream& out) const;
};


//-----------------------------------------------------------------------------
// Had to depart from the paradigm of the other boundary condition types to
// implement FunctionFace. Couldn't use the same single FunctionFace class for
// both whole-Field-element and componentwise functions, because the return 
// of the user-provided function has to be different for the two cases. 
// Instead, left FunctionFace as whole-element-only (no component specification
// allowed) and introduced new ComponentFunctionFace for componentwise, 
// disallowing via runtime error the allComponents specification allowed in all
// the other BC types. --Tim Williams 3/31/1997
//-----------------------------------------------------------------------------

template<class T,
         unsigned D, 
         class M=UniformCartesian<D,double>, 
         class C=typename M::DefaultCentering>
class FunctionFace : public BCondBase<T,D,M,C>
{
public: 
  // Constructor does *not* allow extra one or two arguments specifying
  // components of multicomponent types, as PeriodicFace and all other BC types
  // here do; user must use ComponentFunctionFace for these cases. This
  // constructor only takes the takes arguments for the user-supplied function
  // and for the active face on the mesh to which this BC applies. The function
  // must have return type T (can't return single components; must use the
  // other class ComponentFunctionFace to do this):
  FunctionFace(T (*func)(const T&), unsigned face);

  void apply( Field<T,D,M,C>& );

  BCondBase<T,D,M,C>* clone() const
  {
    return new FunctionFace<T,D,M,C>( *this );
  }

  // Print out information about the BC to a stream.
  virtual void write(std::ostream& out) const;

  // tjw 3/12/1999: see below
  T (*Func)(const T&);

private:
  // tjw 3/12/1999; had to make this public for test/simple/bc2.cpp to work:
  //  T (*Func)(T&);
};


template<class T,
         unsigned D, 
         class M=UniformCartesian<D,double>, 
         class C=typename M::DefaultCentering>
class ComponentFunctionFace : public BCondBase<T,D,M,C>
{
public: 
  // In addition to arguments for FunctionFace, this constructor takes
  // one, or two unsigned's specifying components of multicomponent types like 
  // Vektor/Tenzor/Anti/SymTenzor this BC applies to.
  // One unsigned means apply to component (i), and two means apply to 
  // component (i,j). Note: unlike all other non-FunctionFace BC types here,
  // you *can't* specify nothing or BCondBase<T,D,M,C>::allComponents to 
  // indicate all components; you *must* use FunctionFace class for doing
  // all components. 
  // ComponentFunctionFace() will give a runtime error if you try to construct
  // it for all components (which it defaults to, meaning the default is a
  // runtime error, which should probably be changed some time if somebody can
  // figure out how). This is not as bad as you might think, though; most 
  // likely the user would be specifying T as the return type of his supplied
  // function when he is trying to do the all-component case, in which he'd
  // get a compile error on the type of the constructor argument Func.
  typedef BCondBase<T,D,M,C> BCondBaseTDMC;
  ComponentFunctionFace(typename ApplyToComponentType<T>::type 
                        (*func)( typename ApplyToComponentType<T>::type), 
                        unsigned face,
                        int i = BCondBaseTDMC::allComponents,
                        int j = BCondBaseTDMC::allComponents);

  void apply( Field<T,D,M,C>& );

  BCondBase<T,D,M,C>* clone() const
  {
    return new ComponentFunctionFace<T,D,M,C>( *this );
  }

  // Print out information about the BC to a stream.
  virtual void write(std::ostream& out) const;

  // tjw 3/12/1999: see below
  typename ApplyToComponentType<T>::type 
    (*Func)( typename ApplyToComponentType<T>::type );

private:
  // tjw 3/12/1999; had to make this public for test/simple/bc2.cpp to work:
  //  typename ApplyToComponentType<T>::type 
  //  (*Func)( typename ApplyToComponentType<T>::type );
};


/*
  Special for Conejo: The Eureka boundary condition.
  
  This is an augmented zero boundary condition which sets
  more locations to zero for some cases.
  
  Instead of setting just the guard layers to zero, it sets the guard 
  layers plus one to zero in all cases except one:
  Face centered data (which as all but one dimension cell centered), 
  on the directions in which it is cell centered.  
  
*/

template<class T,
         unsigned D, 
         class M=UniformCartesian<D,double>, 
         class C=typename M::DefaultCentering>
class EurekaFace : public BCondBase<T,D,M,C>
{
public:
  // Constructor takes:
  // face: the face to apply the boundary condition on.
  // i,j : what component of T to apply the boundary condition to.
  // The components default to setting all components.
  // All it has to do is tell the base class to set itself up.
  typedef BCondBase<T,D,M,C> BCondBaseTDMC;
  EurekaFace(unsigned int face,
             int i = BCondBaseTDMC::allComponents,
             int j = BCondBaseTDMC::allComponents)
    : BCondBase<T,D,M,C>(face,i,j) { BCondBase<T,D,M,C>::m_changePhysical = true; }

  // Apply the boundary condition to a given Field.
  virtual void apply( Field<T,D,M,C>& ) ;

  // Make a copy of one of these.
  BCondBase<T,D,M,C>* clone() const
  {
    return new EurekaFace<T,D,M,C>(*this);
  }

  // Print out information about the BC to a stream.
  virtual void write(std::ostream& out) const;

};         


// ----------------------------------------------------------------------------
// TJW added 1/26/1998 as per Blanca's (Jerry Brock's, for the tracer particle
// code) request: this one takes the values of the last two physical elements,
// and linearly extrapolates from the line through them out to all the guard
// elements. This is independent of centering. The intended use is for filling
// global guard layers of a Field of Vektors holding the mesh node position
// values, for which this does the right thing at hi and lo faces (exactly
// right for uniform cartesian meshes, and a reasonable thing to do for
// nonuniform cartesian meshes).
// 
// Had to depart from the paradigm of the other boundary condition types to
// implement LinearExtrapolateFace. Couldn't use the same single
// LinearExtrapolateFace class for both whole-Field-element and componentwise
// functions, because I couldn't figure out how to implement it using PETE and
// applicative templates.  Instead, created LinearExtrapolateFace as
// whole-element-only (no component specification allowed) and separate
// ComponentLinearExtrapolateFace for componentwise, disallowing via runtime
// error the allComponents specification allowed in all the other BC
// types. --Tim Williams 1/26/1999
// ----------------------------------------------------------------------------

template<class T,
         unsigned D, 
         class M=UniformCartesian<D,double>, 
         class C=typename M::DefaultCentering>
class LinearExtrapolateFace : public BCondBase<T,D,M,C>
{
public:
  // Constructor takes zero, one, or two int's specifying components of 
  // multicomponent types like Vektor/Tenzor/Anti/SymTenzor this BC applies to.
  // Zero int's specified means apply to all components; one means apply to
  // component (i), and two means apply to component (i,j),
  typedef BCondBase<T,D,M,C> BCondBaseTDMC;
  LinearExtrapolateFace(unsigned f) :
    BCondBase<T,D,M,C>(f) {}

  // Apply the boundary condition to a given Field.
  virtual void apply( Field<T,D,M,C> &A);

  // Make a copy of the concrete type.
  virtual BCondBase<T,D,M,C>* clone() const
  {
    return new LinearExtrapolateFace<T,D,M,C>( *this );
  }

  // Print out some information about the BC to a given stream.
  virtual void write(std::ostream&) const;

};


template<class T,
         unsigned D, 
         class M=UniformCartesian<D,double>, 
         class C=typename M::DefaultCentering>
class ComponentLinearExtrapolateFace : public BCondBase<T,D,M,C>
{
public:
  // Constructor takes zero, one, or two int's specifying components of 
  // multicomponent types like Vektor/Tenzor/Anti/SymTenzor this BC applies to.
  // Zero int's specified means apply to all components; one means apply to
  // component (i), and two means apply to component (i,j),
  typedef BCondBase<T,D,M,C> BCondBaseTDMC;
  ComponentLinearExtrapolateFace(unsigned f,
                        int i = BCondBaseTDMC::allComponents,
                        int j = BCondBaseTDMC::allComponents) :
    BCondBase<T,D,M,C>(f,i,j) {
      // Disallow specification of all components (default, unfortunately):
      if ( (j == BCondBase<T,D,M,C>::allComponents) &&
           (i == BCondBase<T,D,M,C>::allComponents) )
        ERRORMSG("ComponentLinearExtrapolateFace(): allComponents specified; "
                 << "not allowed; use LinearExtrapolateFace "
                 << "class instead." << endl);
  }

  // Apply the boundary condition to a given Field.
  virtual void apply( Field<T,D,M,C> &A);

  // Make a copy of the concrete type.
  virtual BCondBase<T,D,M,C>* clone() const
  {
    return new ComponentLinearExtrapolateFace<T,D,M,C>( *this );
  }

  // Print out some information about the BC to a given stream.
  virtual void write(std::ostream&) const;

};



template<class T,
         unsigned D, 
         class M=UniformCartesian<D,double>, 
         class C=typename M::DefaultCentering>
class PatchBC : public BCondBase<T,D,M,C>
{
public: 

  //
  // Initialize with a functor and the face to apply that functor to.
  //
  PatchBC(unsigned face);

  //
  // Virtual function to apply this BC to a Field.
  //
  void apply( Field<T,D,M,C>& );

  //
  // Virtual function for the user to supply to apply this BC to
  // a given vnode.
  //
  virtual void applyPatch(typename Field<T,D,M,C>::iterator,
                          const NDIndex<D>&) = 0;

  //
  // Print out information about the BC to a stream.
  //
  virtual void write(std::ostream& out) const
    {
        out << "PatchBC(" << this->getFace() << ")";
    }

private:

};


//
// Define global streaming functions that just call the
// write function for each of the above base classes.
//

template<class T, unsigned D, class M, class C >
inline std::ostream&
operator<<(std::ostream& o, const BCondBase<T,D,M,C>& bc)
{
  bc.write(o);
  return o;
}


template<class T, unsigned D, class M, class C >
inline std::ostream&
operator<<(std::ostream& o, const BConds<T,D,M,C>& bc)
{
  bc.write(o);
  return o;
}


#include "Field/BCond.hpp"

#endif // BCOND_H

/***************************************************************************
 * $RCSfile: BCond.h,v $   $Author: adelmann $
 * $Revision: 1.1.1.1 $   $Date: 2003/01/23 07:40:26 $
 * IPPL_VERSION_ID: $Id: BCond.h,v 1.1.1.1 2003/01/23 07:40:26 adelmann Exp $ 
 ***************************************************************************/