TensorFunction< rank, dim > Class Template Reference
[Functions]

Inheritance diagram for TensorFunction< rank, dim >:

Inheritance graph
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List of all members.

Classes

class  ExcPureFunctionCalled
class  ExcVectorHasWrongSize

Public Types

typedef Tensor< rank, dim > value_type
typedef Tensor< rank+1, dim > gradient_type

Public Member Functions

 TensorFunction (const double initial_time=0.0)
virtual ~TensorFunction ()
virtual value_type value (const Point< dim > &p) const
virtual void value_list (const std::vector< Point< dim > > &points, std::vector< value_type > &values) const
virtual gradient_type gradient (const Point< dim > &p) const
virtual void gradient_list (const std::vector< Point< dim > > &points, std::vector< gradient_type > &gradients) const


Detailed Description

template<int rank, int dim>
class TensorFunction< rank, dim >

This class is a model for a tensor valued function. The interface of the class is mostly the same as that for the Function class, with the exception that it does not support vector-valued functions with several components, but that the return type is always tensor-valued. The returned values of the evaluation of objects of this type are always whole tensors, while for the Function class, one can ask for a specific component only, or use the vector_value function, which however does not return the value, but rather writes it into the address provided by its second argument. The reason for the different behaviour of the classes is that in the case if tensor valued functions, the size of the argument is known to the compiler a priori, such that the correct amount of memory can be allocated on the stack for the return value; on the other hand, for the vector valued functions, the size is not known to the compiler, so memory has to be allocated on the heap, resulting in relatively expensive copy operations. One can therefore consider this class a specialization of the Function class for which the size is known. An additional benefit is that tensors of arbitrary rank can be returned, not only vectors, as for them the size can be determined similarly simply.

Author:
Guido Kanschat, 1999

Member Typedef Documentation

template<int rank, int dim>
typedef Tensor<rank,dim> TensorFunction< rank, dim >::value_type

Define typedefs for the return types of the value functions.

template<int rank, int dim>
typedef Tensor<rank+1,dim> TensorFunction< rank, dim >::gradient_type


Constructor & Destructor Documentation

template<int rank, int dim>
TensorFunction< rank, dim >::TensorFunction ( const double  initial_time = 0.0  ) 

Constructor. May take an initial value for the time variable, which defaults to zero.

template<int rank, int dim>
virtual TensorFunction< rank, dim >::~TensorFunction (  )  [virtual]

Virtual destructor; absolutely necessary in this case, as classes are usually not used by their true type, but rather through pointers to this base class.


Member Function Documentation

template<int rank, int dim>
virtual value_type TensorFunction< rank, dim >::value ( const Point< dim > &  p  )  const [virtual]

Return the value of the function at the given point.

template<int rank, int dim>
virtual void TensorFunction< rank, dim >::value_list ( const std::vector< Point< dim > > &  points,
std::vector< value_type > &  values 
) const [virtual]

Set values to the point values of the function at the points. It is assumed that values already has the right size, i.e. the same size as the points array.

template<int rank, int dim>
virtual gradient_type TensorFunction< rank, dim >::gradient ( const Point< dim > &  p  )  const [virtual]

Return the gradient of the function at the given point.

template<int rank, int dim>
virtual void TensorFunction< rank, dim >::gradient_list ( const std::vector< Point< dim > > &  points,
std::vector< gradient_type > &  gradients 
) const [virtual]

Set gradients to the gradients of the function at the points. It is assumed that values already has the right size, i.e. the same size as the points array.


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

deal.II documentation generated on Sat Aug 15 16:52:27 2009 by doxygen 1.5.9