Index

NAME

FieldConst - constant scalar field

INCLUDE

include "FieldConst.h"

SYNTAX

 class FieldConst : public Field
 {
   NUMT constvalue;

 public:
   FieldConst (const char* name = NULL);
   FieldConst (NUMT value, const char* name = NULL);
  ~FieldConst () {}

   virtual bool ok () const;
   virtual void minmax (NUMT& min, NUMT& max, GridWithPts* grid =NULL) const;

   NUMT& value ()        { return constvalue; }
   NUMT  value () const  { return constvalue; }

   virtual NUMT valuePt (const Ptv(real)& x, real t = DUMMY);
   virtual NUMT valueFEM (const FiniteElement& fe, real t = DUMMY);
   virtual Ptv(NUMT) derivativePt (const Ptv(real)& x, real t);
   virtual void derivativeFEM (Ptv(NUMT)& d, const FiniteElement& fe,
                               real t = DUMMY);

   virtual void fill  (NUMT value);
   virtual void add   (NUMT value);
   virtual void mult  (NUMT value);
   virtual void apply (Func(NUMT) f);
   virtual void add   (Field& field, int power, NUMT front_factor);

   virtual void print (Os os) const;

   virtual Field&   scale ();
   virtual Field& unscale ();


   CLASS_INFO

   VIRTUAL_CAST(FieldConst)
 };

KEYWORDS

scalar field, constant

DESCRIPTION

The  class  implements  a scalar field that is simply a constant.
It may seem as an overkill to have a  special  field  class  with
lots of virtual functions to represent a constant value. However,
the purpose is to offer a complete scalar  field  hierarchy  such
that the programmer can work with a general Field without knowing
whether the field is actually a complicated  finite  element,  an
explicit function or a constant. The FieldConst ensures that con­
stant fields has the same interface as all other fields.  At  the
same  time, the FieldConst gives (nearly) optimal efficiency when
the field is constant.

With the class Field documentation, the functions  and  the  data
should be self-explanatory.

SEE ALSO

class Field.

DEVELOPED BY

SINTEF Applied Mathematics, Oslo, Norway, and University of Oslo,
Dept. of Mathematics, Norway

AUTHOR

Hans Petter Langtangen, SINTEF/UiO