Template Numerical Library version\ main:58f2aa3f5
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TNL::Solvers::IterativeSolverMonitor< Real, Index > Class Template Reference

Object for monitoring convergence of iterative solvers. More...

#include <TNL/Solvers/IterativeSolverMonitor.h>

Inheritance diagram for TNL::Solvers::IterativeSolverMonitor< Real, Index >:
Collaboration diagram for TNL::Solvers::IterativeSolverMonitor< Real, Index >:

Public Types

using IndexType = Index
 A type for indexing.
 
using RealType = Real
 A type of the floating-point arithmetics.
 

Public Member Functions

 IterativeSolverMonitor ()=default
 Construct with no parameters.
 
void refresh () override
 Causes that the monitor prints out the status of the solver.
 
void setIterations (const IndexType &iterations)
 Set number of the current iteration.
 
void setNodesPerIteration (const IndexType &nodes)
 Set the number of nodes of the numerical mesh or lattice.
 
void setResidue (const RealType &residue)
 Set residue of the current approximation of the solution.
 
void setStage (const std::string &stage)
 This method can be used for naming a stage of the monitored solver.
 
void setTime (const RealType &time)
 Set the time of the simulated evolution if it is time dependent.
 
void setTimeStep (const RealType &timeStep)
 Set the time step for time dependent iterative solvers.
 
void setVerbose (const IndexType &verbose)
 Set up the verbosity of the monitor.
 
- Public Member Functions inherited from TNL::Solvers::SolverMonitor
 SolverMonitor ()=default
 Basic construct with no arguments.
 
bool isStopped () const
 Checks whether the main loop was stopped.
 
void runMainLoop ()
 Starts the main loop from which the method SolverMonitor::refresh is called in given time periods.
 
void setRefreshRate (const int &refreshRate)
 Set the time interval between two consecutive calls of SolverMonitor::refresh.
 
void setTimer (Timer &timer)
 Set a timer object for the solver monitor.
 
void stopMainLoop ()
 Stops the main loop of the monitor. See runMainLoop.
 

Protected Member Functions

int getLineWidth ()
 
- Protected Member Functions inherited from TNL::Solvers::SolverMonitor
double getElapsedTime ()
 

Protected Attributes

std::atomic_bool attributes_changed { false }
 
RealType elapsed_time_before_refresh = 0
 
IndexType iterations = 0
 
IndexType iterations_before_refresh = 0
 
RealType last_mlups = 0
 
IndexType nodesPerIteration = 0
 
RealType residue = 0
 
std::atomic_bool saved { false }
 
IndexType saved_iterations = 0
 
RealType saved_residue = 0
 
std::string saved_stage
 
RealType saved_time = 0
 
RealType saved_timeStep = 0
 
std::string stage
 
RealType time = 0
 
RealType timeStep = 0
 
IndexType verbose = 2
 
- Protected Attributes inherited from TNL::Solvers::SolverMonitor
std::atomic_bool started { false }
 
std::atomic_bool stopped { false }
 
std::atomic_int timeout_milliseconds { 500 }
 
Timertimer = nullptr
 

Detailed Description

template<typename Real = double, typename Index = int>
class TNL::Solvers::IterativeSolverMonitor< Real, Index >

Object for monitoring convergence of iterative solvers.

Template Parameters
Realis a type of the floating-point arithmetics.
Indexis an indexing type.

The following example shows how to use the iterative solver monitor for monitoring convergence of linear iterative solver:

1#include <iostream>
2#include <memory>
3#include <chrono>
4#include <thread>
5#include <TNL/Matrices/SparseMatrix.h>
6#include <TNL/Devices/Sequential.h>
7#include <TNL/Devices/Cuda.h>
8#include <TNL/Solvers/Linear/Jacobi.h>
9
10template< typename Device >
11void
12iterativeLinearSolverExample()
13{
14 /***
15 * Set the following matrix (dots represent zero matrix elements):
16 *
17 * / 2.5 -1 . . . \
18 * | -1 2.5 -1 . . |
19 * | . -1 2.5 -1. . |
20 * | . . -1 2.5 -1 |
21 * \ . . . -1 2.5 /
22 */
25 const int size( 5 );
26 auto matrix_ptr = std::make_shared< MatrixType >();
27 matrix_ptr->setDimensions( size, size );
28 matrix_ptr->setRowCapacities( Vector( { 2, 3, 3, 3, 2 } ) );
29
30 auto f = [ = ] __cuda_callable__( typename MatrixType::RowView & row ) mutable
31 {
32 const int rowIdx = row.getRowIndex();
33 if( rowIdx == 0 ) {
34 row.setElement( 0, rowIdx, 2.5 ); // diagonal element
35 row.setElement( 1, rowIdx + 1, -1 ); // element above the diagonal
36 }
37 else if( rowIdx == size - 1 ) {
38 row.setElement( 0, rowIdx - 1, -1.0 ); // element below the diagonal
39 row.setElement( 1, rowIdx, 2.5 ); // diagonal element
40 }
41 else {
42 row.setElement( 0, rowIdx - 1, -1.0 ); // element below the diagonal
43 row.setElement( 1, rowIdx, 2.5 ); // diagonal element
44 row.setElement( 2, rowIdx + 1, -1.0 ); // element above the diagonal
45 }
46 };
47
48 /***
49 * Set the matrix elements.
50 */
51 matrix_ptr->forAllRows( f );
52 std::cout << *matrix_ptr << std::endl;
53
54 /***
55 * Set the right-hand side vector.
56 */
57 Vector x( size, 1.0 );
58 Vector b( size );
59 matrix_ptr->vectorProduct( x, b );
60 x = 0.0;
61 std::cout << "Vector b = " << b << std::endl;
62
63 /***
64 * Setup solver of the linear system.
65 */
67 LinearSolver solver;
68 solver.setMatrix( matrix_ptr );
69 solver.setOmega( 0.0005 );
70
71 /***
72 * Setup monitor of the iterative solver.
73 */
74 using IterativeSolverMonitorType = TNL::Solvers::IterativeSolverMonitor< double, int >;
75 IterativeSolverMonitorType monitor;
76 TNL::Solvers::SolverMonitorThread monitorThread( monitor );
77 monitor.setRefreshRate( 10 ); // refresh rate in milliseconds
78 monitor.setVerbose( 1 );
79 monitor.setStage( "Jacobi stage:" );
80 solver.setSolverMonitor( monitor );
81 solver.setConvergenceResidue( 1.0e-6 );
82 solver.solve( b, x );
83 monitor.stopMainLoop();
84 std::cout << "Vector x = " << x << std::endl;
85}
86
87int
88main( int argc, char* argv[] )
89{
90 std::cout << "Solving linear system on host: " << std::endl;
91 iterativeLinearSolverExample< TNL::Devices::Sequential >();
92
93#ifdef __CUDACC__
94 std::cout << "Solving linear system on CUDA device: " << std::endl;
95 iterativeLinearSolverExample< TNL::Devices::Cuda >();
96#endif
97}
#define __cuda_callable__
Definition Macros.h:49
Vector extends Array with algebraic operations.
Definition Vector.h:36
Implementation of sparse matrix, i.e. matrix storing only non-zero elements.
Definition SparseMatrix.h:57
Iterative solver of linear systems based on the Jacobi method.
Definition Jacobi.h:21
void setMatrix(const MatrixPointer &matrix)
Set the matrix of the linear system.
Definition LinearSolver.h:120
A RAII wrapper for launching the SolverMonitor's main loop in a separate thread.
Definition SolverMonitor.h:133
T endl(T... args)
T make_shared(T... args)

The result looks as follows:

Solving linear system on host:
Row: 0 -> 0:2.5 1:-1
Row: 1 -> 0:-1 1:2.5 2:-1
Row: 2 -> 1:-1 2:2.5 3:-1
Row: 3 -> 2:-1 3:2.5 4:-1
Row: 4 -> 3:-1 4:2.5
Vector b = [ 1.5, 0.5, 0.5, 0.5, 1.5 ]
Vector x = [ 0.999999, 0.999999, 0.999998, 0.999999, 0.999999 ]

The following example shows how to employ timer (TNL::Timer) to the monitor of iterative solvers:

1#include <iostream>
2#include <memory>
3#include <chrono>
4#include <thread>
5#include <TNL/Timer.h>
6#include <TNL/Matrices/SparseMatrix.h>
7#include <TNL/Devices/Sequential.h>
8#include <TNL/Devices/Cuda.h>
9#include <TNL/Solvers/Linear/Jacobi.h>
10
11template< typename Device >
12void
13iterativeLinearSolverExample()
14{
15 /***
16 * Set the following matrix (dots represent zero matrix elements):
17 *
18 * / 2.5 -1 . . . \
19 * | -1 2.5 -1 . . |
20 * | . -1 2.5 -1. . |
21 * | . . -1 2.5 -1 |
22 * \ . . . -1 2.5 /
23 */
26 const int size( 5 );
27 auto matrix_ptr = std::make_shared< MatrixType >();
28 matrix_ptr->setDimensions( size, size );
29 matrix_ptr->setRowCapacities( Vector( { 2, 3, 3, 3, 2 } ) );
30
31 auto f = [ = ] __cuda_callable__( typename MatrixType::RowView & row ) mutable
32 {
33 const int rowIdx = row.getRowIndex();
34 if( rowIdx == 0 ) {
35 row.setElement( 0, rowIdx, 2.5 ); // diagonal element
36 row.setElement( 1, rowIdx + 1, -1 ); // element above the diagonal
37 }
38 else if( rowIdx == size - 1 ) {
39 row.setElement( 0, rowIdx - 1, -1.0 ); // element below the diagonal
40 row.setElement( 1, rowIdx, 2.5 ); // diagonal element
41 }
42 else {
43 row.setElement( 0, rowIdx - 1, -1.0 ); // element below the diagonal
44 row.setElement( 1, rowIdx, 2.5 ); // diagonal element
45 row.setElement( 2, rowIdx + 1, -1.0 ); // element above the diagonal
46 }
47 };
48
49 /***
50 * Set the matrix elements.
51 */
52 matrix_ptr->forAllRows( f );
53 std::cout << *matrix_ptr << std::endl;
54
55 /***
56 * Set the right-hand side vector.
57 */
58 Vector x( size, 1.0 );
59 Vector b( size );
60 matrix_ptr->vectorProduct( x, b );
61 x = 0.0;
62 std::cout << "Vector b = " << b << std::endl;
63
64 /***
65 * Setup solver of the linear system.
66 */
68 LinearSolver solver;
69 solver.setMatrix( matrix_ptr );
70 solver.setOmega( 0.0005 );
71
72 /***
73 * Setup monitor of the iterative solver.
74 */
75 using IterativeSolverMonitorType = TNL::Solvers::IterativeSolverMonitor< double, int >;
76 IterativeSolverMonitorType monitor;
77 TNL::Solvers::SolverMonitorThread mmonitorThread( monitor );
78 monitor.setRefreshRate( 10 ); // refresh rate in milliseconds
79 monitor.setVerbose( 1 );
80 monitor.setStage( "Jacobi stage:" );
81 TNL::Timer timer;
82 monitor.setTimer( timer );
83 timer.start();
84 solver.setSolverMonitor( monitor );
85 solver.setConvergenceResidue( 1.0e-6 );
86 solver.solve( b, x );
87 monitor.stopMainLoop();
88 std::cout << "Vector x = " << x << std::endl;
89}
90
91int
92main( int argc, char* argv[] )
93{
94 std::cout << "Solving linear system on host: " << std::endl;
95 iterativeLinearSolverExample< TNL::Devices::Sequential >();
96
97#ifdef __CUDACC__
98 std::cout << "Solving linear system on CUDA device: " << std::endl;
99 iterativeLinearSolverExample< TNL::Devices::Cuda >();
100#endif
101}
Class for real time, CPU time and CPU cycles measuring.
Definition Timer.h:25
void start()
Starts timer.
Definition Timer.hpp:42

The result looks as follows:

Solving linear system on host:
Row: 0 -> 0:2.5 1:-1
Row: 1 -> 0:-1 1:2.5 2:-1
Row: 2 -> 1:-1 2:2.5 3:-1
Row: 3 -> 2:-1 3:2.5 4:-1
Row: 4 -> 3:-1 4:2.5
Vector b = [ 1.5, 0.5, 0.5, 0.5, 1.5 ]
ELA:6.54e-06
Vector x = [ 0.999999, 0.999999, 0.999998, 0.999999, 0.999999 ]

Member Function Documentation

◆ refresh()

template<typename Real, typename Index>
void TNL::Solvers::IterativeSolverMonitor< Real, Index >::refresh ( )
overridevirtual

Causes that the monitor prints out the status of the solver.

Implements TNL::Solvers::SolverMonitor.

◆ setIterations()

template<typename Real, typename Index>
void TNL::Solvers::IterativeSolverMonitor< Real, Index >::setIterations ( const IndexType & iterations)

Set number of the current iteration.

Parameters
iterationsis number of the current iteration.

◆ setNodesPerIteration()

template<typename Real, typename Index>
void TNL::Solvers::IterativeSolverMonitor< Real, Index >::setNodesPerIteration ( const IndexType & nodes)

Set the number of nodes of the numerical mesh or lattice.

This can be used to compute the number of nodes processed per one second.

Parameters
nodesis number of nodes of the numerical mesh or lattice.

◆ setResidue()

template<typename Real = double, typename Index = int>
void TNL::Solvers::IterativeSolverMonitor< Real, Index >::setResidue ( const RealType & residue)

Set residue of the current approximation of the solution.

Parameters
residueis a residue of the current approximation of the solution.

◆ setStage()

template<typename Real, typename Index>
void TNL::Solvers::IterativeSolverMonitor< Real, Index >::setStage ( const std::string & stage)

This method can be used for naming a stage of the monitored solver.

The stage name can be used to differ between various stages of iterative solvers.

Parameters
stageis name of the solver stage.

◆ setTime()

template<typename Real, typename Index>
void TNL::Solvers::IterativeSolverMonitor< Real, Index >::setTime ( const RealType & time)

Set the time of the simulated evolution if it is time dependent.

This can be used for example when solving parabolic or hyperbolic PDEs.

Parameters
timetime of the simulated evolution.

◆ setTimeStep()

template<typename Real, typename Index>
void TNL::Solvers::IterativeSolverMonitor< Real, Index >::setTimeStep ( const RealType & timeStep)

Set the time step for time dependent iterative solvers.

Parameters
timeSteptime step of the time dependent iterative solver.

◆ setVerbose()

template<typename Real, typename Index>
void TNL::Solvers::IterativeSolverMonitor< Real, Index >::setVerbose ( const IndexType & verbose)

Set up the verbosity of the monitor.

Parameters
verboseis the new value of the verbosity of the monitor.

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