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 |
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.
typedef Tensor<rank,dim> TensorFunction< rank, dim >::value_type |
Define typedefs for the return types of the value
functions.
typedef Tensor<rank+1,dim> TensorFunction< rank, dim >::gradient_type |
TensorFunction< rank, dim >::TensorFunction | ( | const double | initial_time = 0.0 |
) |
Constructor. May take an initial value for the time variable, which defaults to zero.
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.
virtual value_type TensorFunction< rank, dim >::value | ( | const Point< dim > & | p | ) | const [virtual] |
Return the value of the function at the given point.
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.
virtual gradient_type TensorFunction< rank, dim >::gradient | ( | const Point< dim > & | p | ) | const [virtual] |
Return the gradient of the function at the given point.
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.