Reference documentation for deal.II version Git d435e92be9 20200923 09:04:26 0400

#include <deal.II/numerics/data_postprocessor.h>
Public Member Functions  
DataPostprocessorScalar (const std::string &name, const UpdateFlags update_flags)  
virtual std::vector< std::string >  get_names () const override 
virtual std::vector< DataComponentInterpretation::DataComponentInterpretation >  get_data_component_interpretation () const override 
virtual UpdateFlags  get_needed_update_flags () const override 
virtual void  evaluate_scalar_field (const DataPostprocessorInputs::Scalar< dim > &input_data, std::vector< Vector< double >> &computed_quantities) const 
virtual void  evaluate_vector_field (const DataPostprocessorInputs::Vector< dim > &input_data, std::vector< Vector< double >> &computed_quantities) const 
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 
template<class Archive >  
void  serialize (Archive &ar, const unsigned int version) 
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 Attributes  
const std::string  name 
const UpdateFlags  update_flags 
This class provides a simpler interface to the functionality offered by the DataPostprocessor class in case one wants to compute only a single scalar quantity from the finite element field passed to the DataOut class. For this particular case, it is clear what the returned value of DataPostprocessor::get_data_component_interpretation() should be and we pass the values returned by get_names() and get_needed_update_flags() to the constructor so that derived classes do not have to implement these functions by hand.
All derived classes have to do is implement a constructor and overload either DataPostprocessor::evaluate_scalar_field() or DataPostprocessor::evaluate_vector_field() as discussed in the DataPostprocessor class's documentation.
An example of how this class can be used can be found in step29 for the case where we are interested in computing the magnitude (a scalar) of a complexvalued solution. While in step29, the solution vector consists of separate real and imaginary parts of the solution, step58 computes the solution vector as a vector with complex entries and the DataPostprocessorScalar class is used there to compute the magnitude and phase of the solution in a different way there.
An example of how the closely related DataPostprocessorVector class can be used is found in the documentation of that class. The same is true for the DataPostprocessorTensor class.
Definition at line 618 of file data_postprocessor.h.
DataPostprocessorScalar< dim >::DataPostprocessorScalar  (  const std::string &  name, 
const UpdateFlags  update_flags  
) 
Constructor. Take the name of the single scalar variable computed by classes derived from the current one, as well as the update flags necessary to compute this quantity.
name  The name by which the scalar variable computed by this class should be made available in graphical output files. 
update_flags  This has to be a combination of update_values , update_gradients , update_hessians and update_quadrature_points . Note that the flag update_quadrature_points updates DataPostprocessorInputs::CommonInputs::evaluation_points. If the DataPostprocessor is to be used in combination with DataOutFaces, you may also ask for a update of normals via the update_normal_vectors flag. The description of the flags can be found at UpdateFlags. 
Definition at line 60 of file data_postprocessor.cc.

overridevirtual 
Return the vector of strings describing the names of the computed quantities. Given the purpose of this class, this is a vector with a single entry equal to the name given to the constructor.
Implements DataPostprocessor< dim >.
Definition at line 71 of file data_postprocessor.cc.

overridevirtual 
This function returns information about how the individual components of output files that consist of more than one data set are to be interpreted. Since the current class is meant to be used for a single scalar result variable, the returned value is obviously DataComponentInterpretation::component_is_scalar.
Reimplemented from DataPostprocessor< dim >.
Definition at line 80 of file data_postprocessor.cc.

overridevirtual 
Return, which data has to be provided to compute the derived quantities. The flags returned here are the ones passed to the constructor of this class.
Implements DataPostprocessor< dim >.
Definition at line 89 of file data_postprocessor.cc.

virtualinherited 
This is the main function which actually performs the postprocessing. The second argument is a reference to the postprocessed data which already has correct size and must be filled by this function.
The function takes the values, gradients, and higher derivatives of the solution at all evaluation points, as well as other data such as the cell, via the first argument. Not all of the member vectors of this argument will be filled with data – in fact, derivatives and other quantities will only be contain valid data if the corresponding flags are returned by an overridden version of the get_needed_update_flags() function (implemented in a user's derived class). Otherwise those vectors will be in an unspecified state.
This function is called when the finite element field that is being converted into graphical data by DataOut or similar classes represents scalar data, i.e., if the finite element in use has only a single realvalued vector component.
Definition at line 26 of file data_postprocessor.cc.

virtualinherited 
Same as the evaluate_scalar_field() function, but this function is called when the original data vector represents vector data, i.e., the finite element in use has multiple vector components. This function is also called if the finite element is scalar but the solution vector is complexvalued. If the solution vector to be visualized is complexvalued (whether scalar or not), then the input data contains first all real parts of the solution vector at each evaluation point, and then all imaginary parts.
Definition at line 37 of file data_postprocessor.cc.

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 136 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 156 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 290 of file subscriptor.h.

inlineinherited 
List the subscribers to the input stream
.
Definition at line 307 of file subscriptor.h.

inherited 
List the subscribers to deallog
.
Definition at line 204 of file subscriptor.cc.

inlineinherited 
Read or write the data of this object to or from a stream for the purpose of serialization.
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 299 of file subscriptor.h.

private 
Copies of the two arguments given to the constructor of this class.
Definition at line 669 of file data_postprocessor.h.

private 
Definition at line 670 of file data_postprocessor.h.