deal.II version GIT relicensing-1927-g3de9220933 2024-10-03 08:40:00+00:00
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#include <deal.II/lac/solver_control.h>
Classes | |
class | NoConvergence |
Public Types | |
enum | State { iterate = 0 , success , failure } |
Public Member Functions | |
SolverControl (const unsigned int n=100, const double tol=1.e-10, const bool log_history=false, const bool log_result=true) | |
virtual | ~SolverControl () override=default |
void | parse_parameters (ParameterHandler ¶m) |
virtual State | check (const unsigned int step, const double check_value) |
State | last_check () const |
double | initial_value () const |
double | last_value () const |
unsigned int | last_step () const |
unsigned int | max_steps () const |
unsigned int | set_max_steps (const unsigned int) |
void | set_failure_criterion (const double rel_failure_residual) |
void | clear_failure_criterion () |
double | tolerance () const |
double | set_tolerance (const double) |
void | enable_history_data () |
const std::vector< double > & | get_history_data () const |
double | average_reduction () const |
double | final_reduction () const |
double | step_reduction (unsigned int step) const |
void | log_history (const bool) |
bool | log_history () const |
unsigned int | log_frequency (unsigned int) |
void | log_result (const bool) |
bool | log_result () const |
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 ObserverPointer 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 ¶m) |
static ::ExceptionBase & | ExcHistoryDataRequired () |
static ::ExceptionBase & | ExcInUse (int arg1, std::string arg2, std::string arg3) |
static ::ExceptionBase & | ExcNoSubscriber (std::string arg1, std::string arg2) |
Protected Attributes | |
unsigned int | maxsteps |
double | tol |
State | lcheck |
double | initial_val |
double | lvalue |
unsigned int | lstep |
bool | check_failure |
double | relative_failure_residual |
double | failure_residual |
bool | m_log_history |
unsigned int | m_log_frequency |
bool | m_log_result |
bool | history_data_enabled |
std::vector< double > | history_data |
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 | |
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 |
Control class to determine convergence of iterative solvers.
Used by iterative methods to determine whether the iteration should be continued. To this end, the virtual function check()
is called in each iteration with the current iteration step and the value indicating convergence (usually the residual).
After the iteration has terminated, the functions last_value() and last_step() can be used to obtain information about the final state of the iteration.
check() can be replaced in derived classes to allow for more sophisticated tests.
The return states of the check function are of type State, which is an enum local to this class. It indicates the state the solver is in.
The possible values of State are
iterate = 0
: continue the iteration. success:
the goal is reached, the iterative method can terminate successfully. failure:
the iterative method should stop because convergence could not be achieved or at least was not achieved within the given maximal number of iterations. Definition at line 66 of file solver_control.h.
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privateinherited |
The data type used in counter_map.
Definition at line 230 of file subscriptor.h.
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privateinherited |
The iterator type used in counter_map.
Definition at line 235 of file subscriptor.h.
enum SolverControl::State |
Enum denoting the different states a solver can be in. See the general documentation of this class for more information.
Enumerator | |
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iterate | Continue iteration. |
success | Stop iteration, goal reached. |
failure | Stop iteration, goal not reached. |
Definition at line 73 of file solver_control.h.
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explicit |
Constructor. The parameters n
and tol
are the maximum number of iteration steps before failure and the tolerance to determine success of the iteration.
log_history
specifies whether the history (i.e. the value to be checked and the number of the iteration step) shall be printed to deallog
stream. Default is: do not print. Similarly, log_result
specifies the whether the final result is logged to deallog
. Default is yes.
Definition at line 29 of file solver_control.cc.
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overridevirtualdefault |
Virtual destructor is needed as there are virtual functions in this class.
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static |
Interface to parameter file.
Definition at line 206 of file solver_control.cc.
void SolverControl::parse_parameters | ( | ParameterHandler & | param | ) |
Read parameters from file.
Definition at line 217 of file solver_control.cc.
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virtual |
Decide about success or failure of an iteration. This function gets the current iteration step to determine, whether the allowed number of steps has been exceeded and returns failure
in this case. If check_value
is below the prescribed tolerance, it returns success
. In all other cases iterate
is returned to suggest continuation of the iterative procedure.
The iteration is also aborted if the residual becomes a denormalized value (NaN
).
check()
additionally preserves step
and check_value
. These values are accessible by last_value()
and last_step()
.
Derived classes may overload this function, e.g. to log the convergence indicators (check_value
) or to do other computations.
Reimplemented in ReductionControl, IterationNumberControl, and ConsecutiveControl.
Definition at line 51 of file solver_control.cc.
SolverControl::State SolverControl::last_check | ( | ) | const |
Return the result of the last check operation.
Definition at line 108 of file solver_control.cc.
double SolverControl::initial_value | ( | ) | const |
Return the initial convergence criterion.
Definition at line 115 of file solver_control.cc.
double SolverControl::last_value | ( | ) | const |
Return the convergence value of last iteration step for which check
was called by the solver.
Definition at line 122 of file solver_control.cc.
unsigned int SolverControl::last_step | ( | ) | const |
Number of last iteration step.
Definition at line 129 of file solver_control.cc.
unsigned int SolverControl::max_steps | ( | ) | const |
Maximum number of steps.
void SolverControl::set_failure_criterion | ( | const double | rel_failure_residual | ) |
Enables the failure check. Solving is stopped with ReturnState
failure
if residual>failure_residual
with failure_residual := rel_failure_residual*first_residual
.
void SolverControl::clear_failure_criterion | ( | ) |
Disables failure check and resets relative_failure_residual
and failure_residual
to zero.
double SolverControl::tolerance | ( | ) | const |
Tolerance.
double SolverControl::set_tolerance | ( | const double | ) |
Change tolerance.
void SolverControl::enable_history_data | ( | ) |
Enables writing residuals of each step into a vector for later analysis.
Definition at line 147 of file solver_control.cc.
const std::vector< double > & SolverControl::get_history_data | ( | ) | const |
Provide read access to the collected residual data.
Definition at line 155 of file solver_control.cc.
double SolverControl::average_reduction | ( | ) | const |
Average error reduction over all steps.
Requires enable_history_data()
Definition at line 171 of file solver_control.cc.
double SolverControl::final_reduction | ( | ) | const |
Error reduction of the last step; for stationary iterations, this approximates the norm of the iteration matrix.
Requires enable_history_data()
Definition at line 199 of file solver_control.cc.
double SolverControl::step_reduction | ( | unsigned int | step | ) | const |
Error reduction of any iteration step.
Requires enable_history_data()
Definition at line 187 of file solver_control.cc.
void SolverControl::log_history | ( | const bool | ) |
Log each iteration step. Use log_frequency
for skipping steps.
bool SolverControl::log_history | ( | ) | const |
Return the log_history
flag.
Set logging frequency.
Definition at line 136 of file solver_control.cc.
void SolverControl::log_result | ( | const bool | ) |
Log start and end step.
bool SolverControl::log_result | ( | ) | const |
Return the log_result
flag.
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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 130 of file subscriptor.cc.
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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 150 of file subscriptor.cc.
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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 301 of file subscriptor.h.
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inlineinherited |
List the subscribers to the input stream
.
Definition at line 318 of file subscriptor.h.
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inherited |
List the subscribers to deallog
.
Definition at line 198 of file subscriptor.cc.
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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 310 of file subscriptor.h.
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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.
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protected |
Maximum number of steps.
Definition at line 334 of file solver_control.h.
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protected |
Prescribed tolerance to be achieved.
Definition at line 339 of file solver_control.h.
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protected |
Result of last check operation.
Definition at line 344 of file solver_control.h.
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protected |
Initial value.
Definition at line 349 of file solver_control.h.
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protected |
Last value of the convergence criterion.
Definition at line 354 of file solver_control.h.
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protected |
Last step.
Definition at line 359 of file solver_control.h.
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protected |
Is set to true
by set_failure_criterion
and enables failure checking.
Definition at line 365 of file solver_control.h.
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protected |
Stores the rel_failure_residual
set by set_failure_criterion
Definition at line 370 of file solver_control.h.
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protected |
failure_residual
equals the first residual multiplied by relative_crit
set by set_failure_criterion
(see there).
Until the first residual is known it is 0.
Definition at line 378 of file solver_control.h.
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protected |
Log convergence history to deallog
.
Definition at line 383 of file solver_control.h.
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protected |
Log only every nth step.
Definition at line 388 of file solver_control.h.
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protected |
Log iteration result to deallog
. If true, after finishing the iteration, a statement about failure or success together with lstep
and lvalue
are logged.
Definition at line 395 of file solver_control.h.
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protected |
Control over the storage of history data. Set by enable_history_data().
Definition at line 400 of file solver_control.h.
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protected |
Vector storing the result after each iteration step for later statistical analysis.
Use of this vector is enabled by enable_history_data().
Definition at line 408 of file solver_control.h.
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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 219 of file subscriptor.h.
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mutableprivateinherited |
In this map, we count subscriptions for each different identification string supplied to subscribe().
Definition at line 225 of file subscriptor.h.
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mutableprivateinherited |
In this vector, we store pointers to the validity bool in the ObserverPointer objects that subscribe to this class.
Definition at line 241 of file subscriptor.h.
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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 249 of file subscriptor.h.
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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 272 of file subscriptor.h.