Reference documentation for deal.II version GIT relicensing-837-gaf73e64026 2024-06-15 22:40:02+00:00
\(\newcommand{\dealvcentcolon}{\mathrel{\mathop{:}}}\) \(\newcommand{\dealcoloneq}{\dealvcentcolon\mathrel{\mkern-1.2mu}=}\) \(\newcommand{\jump}[1]{\left[\!\left[ #1 \right]\!\right]}\) \(\newcommand{\average}[1]{\left\{\!\left\{ #1 \right\}\!\right\}}\)
No Matches
Public Member Functions | Static Public Member Functions | Private Types | Private Member Functions | Private Attributes | Static Private Attributes | List of all members
Algorithms::TimestepControl Class Reference

#include <deal.II/algorithms/timestep_control.h>

Inheritance diagram for Algorithms::TimestepControl:
Inheritance graph

Public Member Functions

 TimestepControl (double start=0., double final=1., double tolerance=1.e-2, double start_step=1.e-2, double print_step=-1., double max_step=1.)
void parse_parameters (ParameterHandler &param)
double start () const
double final () const
double tolerance () const
double step () const
double now () const
bool advance ()
void start (double)
void final (double)
void tolerance (double)
void start_step (const double step)
void max_step (double)
void restart ()
bool print ()
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 void declare_parameters (ParameterHandler &param)
static ::ExceptionBaseExcInUse (int arg1, std::string arg2, std::string arg3)
static ::ExceptionBaseExcNoSubscriber (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

double start_val
double final_val
double tolerance_val
double start_step_val
double max_step_val
double min_step_val
double current_step_val
double step_val
double now_val
double print_step
double next_print_val
std::atomic< unsigned intcounter
std::map< std::string, unsigned intcounter_map
std::vector< std::atomic< bool > * > validity_pointers
const std::type_info * object_info

Static Private Attributes

static std::mutex mutex

Detailed Description

Control class for timestepping schemes. Its main task is determining the size of the next time step and the according point in the time interval. Additionally, it controls writing the solution to a file.

The size of the next time step is determined as follows:

  1. According to the strategy, the step size is tentatively added to the current time.
  2. If the resulting time exceeds the final time of the interval, the step size is reduced in order to meet this time.
  3. If the resulting time is below the final time by just a fraction of the step size, the step size is increased in order to meet this time.
  4. The resulting step size is used from the current time.

The variable print_step can be used to control the amount of output generated by the timestepping scheme.

Many of the features of this class are available in DiscreteTime with a more modern interface and better programming guarantees. Consider using DiscreteTime instead of TimestepControl.

Definition at line 60 of file timestep_control.h.

Member Typedef Documentation

◆ map_value_type

using Subscriptor::map_value_type = decltype(counter_map)::value_type

The data type used in counter_map.

Definition at line 229 of file subscriptor.h.

◆ map_iterator

using Subscriptor::map_iterator = decltype(counter_map)::iterator

The iterator type used in counter_map.

Definition at line 234 of file subscriptor.h.

Constructor & Destructor Documentation

◆ TimestepControl()

Algorithms::TimestepControl::TimestepControl ( double  start = 0.,
double  final = 1.,
double  tolerance = 1.e-2,
double  start_step = 1.e-2,
double  print_step = -1.,
double  max_step = 1. 

Constructor setting default values

Definition at line 24 of file

Member Function Documentation

◆ declare_parameters()

void Algorithms::TimestepControl::declare_parameters ( ParameterHandler param)

Declare the control parameters for parameter handler.

Definition at line 50 of file

◆ parse_parameters()

void Algorithms::TimestepControl::parse_parameters ( ParameterHandler param)

Read the control parameters from a parameter handler.

This function also calls restart() to reset all other internal parameters of this class to their appropriate values based on the parameters just read.

Definition at line 63 of file

◆ start() [1/2]

double Algorithms::TimestepControl::start ( ) const

Return the left end of the time interval.

Definition at line 231 of file timestep_control.h.

◆ final() [1/2]

double Algorithms::TimestepControl::final ( ) const

Return the right end of the time interval. The control mechanism ensures that the final time step ends at this point.

Definition at line 238 of file timestep_control.h.

◆ tolerance() [1/2]

double Algorithms::TimestepControl::tolerance ( ) const

Return the tolerance value controlling the time steps.

Definition at line 252 of file timestep_control.h.

◆ step()

double Algorithms::TimestepControl::step ( ) const

Return the size of the current time step.

Definition at line 245 of file timestep_control.h.

◆ now()

double Algorithms::TimestepControl::now ( ) const

Return the current time.

Definition at line 259 of file timestep_control.h.

◆ advance()

bool Algorithms::TimestepControl::advance ( )

Compute the size of the next step and return true if it differs from the current step size. Advance the current time by the new step size.

Definition at line 76 of file

◆ start() [2/2]

void Algorithms::TimestepControl::start ( double  t)

Set start value.

Definition at line 266 of file timestep_control.h.

◆ final() [2/2]

void Algorithms::TimestepControl::final ( double  t)

Set final time value.

Definition at line 273 of file timestep_control.h.

◆ tolerance() [2/2]

void Algorithms::TimestepControl::tolerance ( double  t)

Set tolerance

Definition at line 280 of file timestep_control.h.

◆ start_step()

void Algorithms::TimestepControl::start_step ( const double  step)

Set size of the first step. This may be overwritten by the time stepping strategy.

[in]stepThe size of the first step, which may be overwritten by the time stepping strategy.

Definition at line 287 of file timestep_control.h.

◆ max_step()

void Algorithms::TimestepControl::max_step ( double  t)

Set size of the maximum step size.

Definition at line 294 of file timestep_control.h.

◆ restart()

void Algorithms::TimestepControl::restart ( )

Set now() equal to start(). Initialize step() and print() to their initial values.

Definition at line 301 of file timestep_control.h.

◆ print()

bool Algorithms::TimestepControl::print ( )

Return true if this timestep should be written to disk.

Definition at line 101 of file

◆ subscribe()

void Subscriptor::subscribe ( std::atomic< bool > *const  validity,
const std::string &  identifier = "" 
) const

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

◆ unsubscribe()

void Subscriptor::unsubscribe ( std::atomic< bool > *const  validity,
const std::string &  identifier = "" 
) const

Unsubscribes a user from the object.

The identifier and the validity pointer must be the same as the one supplied to subscribe().

Definition at line 155 of file

◆ n_subscriptions()

unsigned int Subscriptor::n_subscriptions ( ) const

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.

◆ list_subscribers() [1/2]

template<typename StreamType >
void Subscriptor::list_subscribers ( StreamType &  stream) const

List the subscribers to the input stream.

Definition at line 317 of file subscriptor.h.

◆ list_subscribers() [2/2]

void Subscriptor::list_subscribers ( ) const

List the subscribers to deallog.

Definition at line 203 of file

◆ serialize()

template<class Archive >
void Subscriptor::serialize ( Archive &  ar,
const unsigned int  version 

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.

◆ check_no_subscribers()

void Subscriptor::check_no_subscribers ( ) const

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.

Since this function is just a consistency check it does nothing in release mode.
If this function is called when there is an uncaught exception then, rather than aborting, this function prints an error message to the standard error stream and returns.

Definition at line 52 of file

Member Data Documentation

◆ start_val

double Algorithms::TimestepControl::start_val

The beginning of the time interval.

Definition at line 173 of file timestep_control.h.

◆ final_val

double Algorithms::TimestepControl::final_val

The end of the time interval.

Definition at line 178 of file timestep_control.h.

◆ tolerance_val

double Algorithms::TimestepControl::tolerance_val

The tolerance value controlling the time steps.

Definition at line 183 of file timestep_control.h.

◆ start_step_val

double Algorithms::TimestepControl::start_step_val

The size of the first step.

Definition at line 188 of file timestep_control.h.

◆ max_step_val

double Algorithms::TimestepControl::max_step_val

The maximum step size.

Definition at line 193 of file timestep_control.h.

◆ min_step_val

double Algorithms::TimestepControl::min_step_val

The minimum step size.

Definition at line 198 of file timestep_control.h.

◆ current_step_val

double Algorithms::TimestepControl::current_step_val

The size of the current time step. This may differ from step_val, if we aim at final_val.

Definition at line 204 of file timestep_control.h.

◆ step_val

double Algorithms::TimestepControl::step_val

The size of the current time step determined by the strategy. This may differ from current_step_val, if we aim at final_val.

Definition at line 210 of file timestep_control.h.

◆ now_val

double Algorithms::TimestepControl::now_val

The current time.

Definition at line 215 of file timestep_control.h.

◆ print_step

double Algorithms::TimestepControl::print_step

Determines the approximate time interval between generated outputs. If negative, output will be generated at all time steps.

Definition at line 221 of file timestep_control.h.

◆ next_print_val

double Algorithms::TimestepControl::next_print_val

If current time exceeds this value, it is time to generate the output.

Definition at line 226 of file timestep_control.h.

◆ counter

std::atomic<unsigned int> Subscriptor::counter

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.

◆ counter_map

std::map<std::string, unsigned int> Subscriptor::counter_map

In this map, we count subscriptions for each different identification string supplied to subscribe().

Definition at line 224 of file subscriptor.h.

◆ validity_pointers

std::vector<std::atomic<bool> *> Subscriptor::validity_pointers

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.

◆ object_info

const std::type_info* Subscriptor::object_info

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.

◆ mutex

std::mutex Subscriptor::mutex

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.

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