From 29bbaef605830d75bdc0b872cc059de3cc681ac3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Tom=C3=A1=C5=A1=20Oberhuber?= <oberhuber.tomas@gmail.com>
Date: Wed, 29 Dec 2021 14:00:35 +0100
Subject: [PATCH] Added example on linear iterative solvers with monitor and
timer.
---
.../Examples/Solvers/Linear/CMakeLists.txt | 1 +
.../IterativeLinearSolverWithTimerExample.cpp | 101 ++++++++++++++++++
.../IterativeLinearSolverWithTimerExample.cu | 1 +
3 files changed, 103 insertions(+)
create mode 100644 Documentation/Examples/Solvers/Linear/IterativeLinearSolverWithTimerExample.cpp
create mode 120000 Documentation/Examples/Solvers/Linear/IterativeLinearSolverWithTimerExample.cu
diff --git a/Documentation/Examples/Solvers/Linear/CMakeLists.txt b/Documentation/Examples/Solvers/Linear/CMakeLists.txt
index 6cc75f08eb..a07ba232a4 100644
--- a/Documentation/Examples/Solvers/Linear/CMakeLists.txt
+++ b/Documentation/Examples/Solvers/Linear/CMakeLists.txt
@@ -1,6 +1,7 @@
set( COMMON_EXAMPLES
IterativeLinearSolverExample
IterativeLinearSolverWithMonitorExample
+ IterativeLinearSolverWithTimerExample
)
if( BUILD_CUDA )
diff --git a/Documentation/Examples/Solvers/Linear/IterativeLinearSolverWithTimerExample.cpp b/Documentation/Examples/Solvers/Linear/IterativeLinearSolverWithTimerExample.cpp
new file mode 100644
index 0000000000..278ccbad0e
--- /dev/null
+++ b/Documentation/Examples/Solvers/Linear/IterativeLinearSolverWithTimerExample.cpp
@@ -0,0 +1,101 @@
+#include <iostream>
+#include <memory>
+#include <chrono>
+#include <thread>
+#include <TNL/Timer.h>
+#include <TNL/Algorithms/ParallelFor.h>
+#include <TNL/Matrices/SparseMatrix.h>
+#include <TNL/Devices/Sequential.h>
+#include <TNL/Devices/Cuda.h>
+#include <TNL/Solvers/Linear/Jacobi.h>
+
+template< typename Device >
+void iterativeLinearSolverExample()
+{
+ /***
+ * Set the following matrix (dots represent zero matrix elements):
+ *
+ * / 2.5 -1 . . . \
+ * | -1 2.5 -1 . . |
+ * | . -1 2.5 -1. . |
+ * | . . -1 2.5 -1 |
+ * \ . . . -1 2.5 /
+ */
+ using MatrixType = TNL::Matrices::SparseMatrix< double, Device >;
+ using Vector = TNL::Containers::Vector< double, Device >;
+ const int size( 5 );
+ auto matrix_ptr = std::make_shared< MatrixType >();
+ matrix_ptr->setDimensions( size, size );
+ matrix_ptr->setRowCapacities( Vector( { 2, 3, 3, 3, 2 } ) );
+
+ auto f = [=] __cuda_callable__ ( typename MatrixType::RowView& row ) mutable {
+ const int rowIdx = row.getRowIndex();
+ if( rowIdx == 0 )
+ {
+ row.setElement( 0, rowIdx, 2.5 ); // diagonal element
+ row.setElement( 1, rowIdx+1, -1 ); // element above the diagonal
+ }
+ else if( rowIdx == size - 1 )
+ {
+ row.setElement( 0, rowIdx-1, -1.0 ); // element below the diagonal
+ row.setElement( 1, rowIdx, 2.5 ); // diagonal element
+ }
+ else
+ {
+ row.setElement( 0, rowIdx-1, -1.0 ); // element below the diagonal
+ row.setElement( 1, rowIdx, 2.5 ); // diagonal element
+ row.setElement( 2, rowIdx+1, -1.0 ); // element above the diagonal
+ }
+ };
+
+ /***
+ * Set the matrix elements.
+ */
+ matrix_ptr->forAllRows( f );
+ std::cout << *matrix_ptr << std::endl;
+
+ /***
+ * Set the right-hand side vector
+ */
+ Vector x( size, 1.0 );
+ Vector b( size );
+ matrix_ptr->vectorProduct( x, b );
+ x = 0.0;
+ std::cout << "Vector b = " << b << std::endl;
+
+ /***
+ * Setup solver of the linear system
+ */
+ using LinearSolver = TNL::Solvers::Linear::Jacobi< MatrixType >;
+ LinearSolver solver;
+ solver.setMatrix( matrix_ptr );
+ solver.setOmega( 0.0005 );
+
+ /***
+ * Setup monitor of the iterative solver
+ */
+ using IterativeSolverMonitorType = TNL::Solvers::IterativeSolverMonitor< double, int >;
+ IterativeSolverMonitorType monitor;
+ TNL::Solvers::SolverMonitorThread mmonitorThread(monitor);
+ monitor.setRefreshRate(10); // refresh rate in milliseconds
+ monitor.setVerbose(1);
+ monitor.setStage( "Jacobi stage:" );
+ TNL::Timer timer;
+ monitor.setTimer( timer );
+ timer.start();
+ solver.setSolverMonitor(monitor);
+ solver.solve( b, x );
+ monitor.stopMainLoop();
+ std::cout << "Vector x = " << x << std::endl;
+}
+
+int main( int argc, char* argv[] )
+{
+ std::cout << "Solving linear system on host: " << std::endl;
+ iterativeLinearSolverExample< TNL::Devices::Sequential >();
+
+#ifdef HAVE_CUDA
+ std::cout << "Solving linear system on CUDA device: " << std::endl;
+ iterativeLinearSolverExample< TNL::Devices::Cuda >();
+#endif
+}
diff --git a/Documentation/Examples/Solvers/Linear/IterativeLinearSolverWithTimerExample.cu b/Documentation/Examples/Solvers/Linear/IterativeLinearSolverWithTimerExample.cu
new file mode 120000
index 0000000000..4c497154d2
--- /dev/null
+++ b/Documentation/Examples/Solvers/Linear/IterativeLinearSolverWithTimerExample.cu
@@ -0,0 +1 @@
+IterativeLinearSolverWithTimerExample.cpp
\ No newline at end of file
--
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