Reference documentation for deal.II version 9.6.0

#include <deal.II/base/tensor_function.h>
Public Types  
using  value_type = Tensor<rank, dim, Number> 
using  gradient_type = Tensor<rank + 1, dim, Number> 
using  time_type 
Public Member Functions  
TensorFunction (const time_type initial_time=time_type(0.0))  
virtual  ~TensorFunction () override=default 
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 
numbers::NumberTraits< double >::real_type  get_time () const 
virtual void  set_time (const numbers::NumberTraits< double >::real_type new_time) 
virtual void  advance_time (const numbers::NumberTraits< double >::real_type delta_t) 
template<class Archive >  
void  serialize (Archive &ar, const unsigned int version) 
Subscriptor functionality  
Classes derived from Subscriptor provide a facility to subscribe to this object. This is mostly used by the SmartPointer class.  
void  subscribe (std::atomic< bool > *const validity, const std::string &identifier="") const 
void  unsubscribe (std::atomic< bool > *const validity, const std::string &identifier="") const 
unsigned int  n_subscriptions () const 
template<typename StreamType >  
void  list_subscribers (StreamType &stream) const 
void  list_subscribers () const 
Static Public Member Functions  
static ::ExceptionBase &  ExcInUse (int arg1, std::string arg2, std::string arg3) 
static ::ExceptionBase &  ExcNoSubscriber (std::string arg1, std::string arg2) 
Private Types  
using  map_value_type = decltype(counter_map)::value_type 
using  map_iterator = decltype(counter_map)::iterator 
Private Member Functions  
void  check_no_subscribers () const noexcept 
Private Attributes  
numbers::NumberTraits< double >::real_type  time 
std::atomic< unsigned int >  counter 
std::map< std::string, unsigned int >  counter_map 
std::vector< std::atomic< bool > * >  validity_pointers 
const std::type_info *  object_info 
Static Private Attributes  
static std::mutex  mutex 
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 vectorvalued functions with several components, but that the return type is always tensorvalued. 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 behavior of the classes is that in the case of 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.
Definition at line 55 of file tensor_function.h.
using TensorFunction< rank, dim, Number >::value_type = Tensor<rank, dim, Number> 
Alias for the return types of the value
function.
Definition at line 63 of file tensor_function.h.
using TensorFunction< rank, dim, Number >::gradient_type = Tensor<rank + 1, dim, Number> 
Alias for the return types of the gradient
functions.
Definition at line 68 of file tensor_function.h.
using TensorFunction< rank, dim, Number >::time_type 
The scalarvalued real type used for representing time.
Definition at line 73 of file tensor_function.h.

privateinherited 
The data type used in counter_map.
Definition at line 229 of file subscriptor.h.

privateinherited 
The iterator type used in counter_map.
Definition at line 234 of file subscriptor.h.
TensorFunction< rank, dim, Number >::TensorFunction  (  const time_type  initial_time = time_type(0.0)  ) 
Constructor. May take an initial value for the time variable, which defaults to zero.

overridevirtualdefault 
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 
Return the value of the function at the given point.
Reimplemented in ConstantTensorFunction< rank, dim, Number >, ConstantTensorFunction< rank, dim, double >, and TensorFunctionParser< rank, dim, Number >.

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 
Return the gradient of the function at the given point.
Reimplemented in ConstantTensorFunction< rank, dim, Number >, and ConstantTensorFunction< rank, dim, double >.

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.

inherited 
Return the value of the time variable.

virtualinherited 
Set the time to new_time
, overwriting the old value.

virtualinherited 
Advance the time by the given time step delta_t
.

inherited 
Subscribes a user of the object by storing the pointer validity
. The subscriber may be identified by text supplied as identifier
.
Definition at line 135 of file subscriptor.cc.

inherited 
Unsubscribes a user from the object.
identifier
and the validity
pointer must be the same as the one supplied to subscribe(). Definition at line 155 of file subscriptor.cc.

inlineinherited 
Return the present number of subscriptions to this object. This allows to use this class for reference counted lifetime determination where the last one to unsubscribe also deletes the object.
Definition at line 300 of file subscriptor.h.

inlineinherited 
List the subscribers to the input stream
.
Definition at line 317 of file subscriptor.h.

inherited 
List the subscribers to deallog
.
Definition at line 203 of file subscriptor.cc.

inlineinherited 
Read or write the data of this object to or from a stream for the purpose of serialization using the BOOST serialization library.
This function does not actually serialize any of the member variables of this class. The reason is that what this class stores is only who subscribes to this object, but who does so at the time of storing the contents of this object does not necessarily have anything to do with who subscribes to the object when it is restored. Consequently, we do not want to overwrite the subscribers at the time of restoring, and then there is no reason to write the subscribers out in the first place.
Definition at line 309 of file subscriptor.h.

privatenoexceptinherited 
Check that there are no objects subscribing to this object. If this check passes then it is safe to destroy the current object. It this check fails then this function will either abort or print an error message to deallog (by using the AssertNothrow mechanism), but will not throw an exception.
Definition at line 52 of file subscriptor.cc.

privateinherited 
Store the present time.
Definition at line 112 of file function_time.h.

mutableprivateinherited 
Store the number of objects which subscribed to this object. Initially, this number is zero, and upon destruction it shall be zero again (i.e. all objects which subscribed should have unsubscribed again).
The creator (and owner) of an object is counted in the map below if HE manages to supply identification.
We use the mutable
keyword in order to allow subscription to constant objects also.
This counter may be read from and written to concurrently in multithreaded code: hence we use the std::atomic
class template.
Definition at line 218 of file subscriptor.h.

mutableprivateinherited 
In this map, we count subscriptions for each different identification string supplied to subscribe().
Definition at line 224 of file subscriptor.h.

mutableprivateinherited 
In this vector, we store pointers to the validity bool in the SmartPointer objects that subscribe to this class.
Definition at line 240 of file subscriptor.h.

mutableprivateinherited 
Pointer to the typeinfo object of this object, from which we can later deduce the class name. Since this information on the derived class is neither available in the destructor, nor in the constructor, we obtain it in between and store it here.
Definition at line 248 of file subscriptor.h.

staticprivateinherited 
A mutex used to ensure data consistency when accessing the mutable
members of this class. This lock is used in the subscribe() and unsubscribe() functions, as well as in list_subscribers()
.
Definition at line 271 of file subscriptor.h.