Index

NAME

Fields  -  base class for collection of scalar fields (ie. vector
fields)

INCLUDE

include "Field.h"

SYNTAX

 class Fields : public virtual HandleId
 {
 protected:
   String fieldname;
 public:

   Fields (const char* fieldname = NULL);
   virtual ~Fields ();

   void setFieldname (const char* name);
   String getFieldname () const           { return fieldname; }
   bool hasFieldname () const;

   virtual Field* getFieldBase (int i = 1) const;
   virtual void attach (Field& field, int i = 1);

   virtual void redim (int nsf, const char* fieldname);
   virtual bool ok () const;

   virtual int getNoFields () const;
   virtual int getNoValues () const;

   virtual void valuePt   (Ptv(NUMT)& vec, const Ptv(real)& x, real t = DUMMY);
   virtual void valueFEM  (Ptv(NUMT)& vec, const FiniteElement& fe,
                           real t = DUMMY);
   virtual void valueNode (Ptv(NUMT)& vec, int node) const;

   virtual void print
     (Os os, const char* heading = "0rinting of Fields object") const;

   virtual Grid* getGridBase();

   CLASS_INFO

   DEF_VIRTUAL_CAST(FieldsLattice)
   DEF_VIRTUAL_CAST(FieldsFE)
   DEF_VIRTUAL_CAST(FieldsWithPtValues)
   DEF_VIRTUAL_CAST(FieldsScatPt)
   DEF_VIRTUAL_CAST(FieldsPiWisConst)
   DEF_VIRTUAL_CAST(FieldsFunc)
   DEF_VIRTUAL_CAST(FieldsConst)
 };

KEYWORDS

vector field, base class

DESCRIPTION

The class represents the base class for vector  fields.  It  con­
tains  simply  a  collection  of scalar fields of type Field. All
subclasses implement their own collection of their specific field
type. See class Field for documentation.

Fields and its subclasses are not limited to vector fields. Since
subclasses implement the vector field in terms  of  a  vector  of
pointers  to  fields  (actually  handles,  Handle(Field)),  it is
straightforward to represent tensor fields. In 3D, a typical ten­
sor field requires six scalar fields.

MEMBER FUNCTIONS

Many member functions are described in class Fields.

getFieldBase  -  returns a Field base class pointer for component
number i in the vector field. Used  when  reading/writing  vector
fields from/to SimRes files.

attach - attaches a scalar field ascomponent number i in the vec­
tor field.

redim - redimensions the number of scalar fields that make up the
vector field.

getNoFields  -  returns  the number of scalar fields that make up
the vector field.

getNoValues - returns the total number of degrees of  freedom  in
the  vector  field.  For example, for a 3D velocity field, repre­
sented in terms of trilinear finite elements with  X  nodes,  the
getNoValues function should return 3*X.

getGridBase  - enables access to the (common) underlying grid for
the field components. NOTE: This  function  will  return  a  NULL
pointer  in  many  subclasses  of Fields. It is, at present, only
used for some special vector field classes.

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