diff --git a/src/UnitTests/Matrices/SymmetricSparseMatrixTest.h b/src/UnitTests/Matrices/SymmetricSparseMatrixTest.h
new file mode 100644
index 0000000000000000000000000000000000000000..fd6bd84641b05059426bfa7ff1691e22749bf780
--- /dev/null
+++ b/src/UnitTests/Matrices/SymmetricSparseMatrixTest.h
@@ -0,0 +1,1304 @@
+/***************************************************************************
+                          SymmetricSparseMatrixTest.h -  description
+                             -------------------
+    begin                : Feb 7, 2020
+    copyright            : (C) 2020 by Tomas Oberhuber et al.
+    email                : tomas.oberhuber@fjfi.cvut.cz
+ ***************************************************************************/
+
+/* See Copyright Notice in tnl/Copyright */
+
+#include <TNL/Containers/Vector.h>
+#include <TNL/Containers/VectorView.h>
+#include <TNL/Math.h>
+#include <TNL/Algorithms/ParallelFor.h>
+#include <iostream>
+#include <sstream>
+
+#ifdef HAVE_GTEST
+#include <gtest/gtest.h>
+
+template< typename MatrixHostFloat, typename MatrixHostInt >
+void host_test_GetType()
+{
+   bool testRan = false;
+   EXPECT_TRUE( testRan );
+   std::cout << "\nTEST DID NOT RUN. NOT WORKING.\n\n";
+   std::cerr << "This test has not been implemented properly yet.\n" << std::endl;
+}
+
+template< typename MatrixCudaFloat, typename MatrixCudaInt >
+void cuda_test_GetType()
+{
+   bool testRan = false;
+   EXPECT_TRUE( testRan );
+   std::cout << "\nTEST DID NOT RUN. NOT WORKING.\n\n";
+   std::cerr << "This test has not been implemented properly yet.\n" << std::endl;
+}
+
+template< typename Matrix >
+void test_SetDimensions()
+{
+   using RealType = typename Matrix::RealType;
+   using DeviceType = typename Matrix::DeviceType;
+   using IndexType = typename Matrix::IndexType;
+
+   const IndexType rows = 9;
+   const IndexType cols = 8;
+
+   Matrix m;
+   m.setDimensions( rows, cols );
+
+   EXPECT_EQ( m.getRows(), 9 );
+   EXPECT_EQ( m.getColumns(), 8 );
+}
+
+template< typename Matrix >
+void test_SetCompressedRowLengths()
+{
+   using RealType = typename Matrix::RealType;
+   using DeviceType = typename Matrix::DeviceType;
+   using IndexType = typename Matrix::IndexType;
+
+   /*
+    /  1  2  4  7                       \
+    |  2  3  5  8 10 13 16 19           |
+    |  4  5  6    11 14       21 24 27  |
+    |  7  8     9       17 20           |
+    |    10 11    12          22 25     |
+    |    13 14       15             28  |
+    |    16    17       18              |
+    |    19    20          21           |
+    |       21    22          23        |
+    |       24    25             26     |
+    \       27       28             30  /
+    */
+   const IndexType rows = 10;
+   const IndexType cols = 11;
+
+   Matrix m( rows, cols );
+   typename Matrix::CompressedRowLengthsVector rowLengths { 1, 2, 3, 3, 3, 3, 3, 3, 3, 3  };
+   m.setCompressedRowLengths( rowLengths );
+
+   // Insert values into the rows.
+   RealType value = 1;
+
+   // 0th row - lower part
+   m.setElement( 0, 0, value++ );
+
+   // 1st row - lower part
+   m.setElement( 1, 0, value++ );
+   m.setElement( 1, 1, value++ );
+
+   // 2nd row - lower part
+   m.setElement( 2, 0, value++ );
+   m.setElement( 2, 1, value++ );
+   m.setElement( 2, 2, value++ );
+
+   // 3rd row - lower part
+   m.setElement( 3, 0, value++ );
+   m.setElement( 3, 1, value++ );
+   m.setElement( 3, 3, value++ );
+
+   // 4th row - lower part
+   m.setElement( 4, 1, value++ );
+   m.setElement( 4, 2, value++ );
+   m.setElement( 4, 4, value++ );
+
+   // 5th row - lower part
+   m.setElement( 5, 1, value++ );
+   m.setElement( 5, 2, value++ );
+   m.setElement( 5, 5, value++ );
+
+   // 6th row - lower part
+   m.setElement( 6, 1, value++ );
+   m.setElement( 6, 3, value++ );
+   m.setElement( 6, 6, value++ );
+
+   // 7th row - lower part
+   m.setElement( 7, 1, value++ );
+   m.setElement( 7, 3, value++ );
+   m.setElement( 7, 7, value++ );
+
+   rowLengths = 0;
+   m.getCompressedRowLengths( rowLengths );
+   typename Matrix::CompressedRowLengthsVector correctRowLengths{ 1, 2, 3, 3, 3, 3, 3, 3, 3, 3 };
+   EXPECT_EQ( rowLengths, correctRowLengths );
+}
+
+template< typename Matrix1, typename Matrix2 >
+void test_SetLike()
+{
+   using RealType = typename Matrix1::RealType;
+   using DeviceType = typename Matrix1::DeviceType;
+   using IndexType = typename Matrix1::IndexType;
+
+   const IndexType rows = 8;
+   const IndexType cols = 7;
+
+   Matrix1 m1( rows + 1, cols + 2 );
+   Matrix2 m2( rows, cols );
+
+   m1.setLike( m2 );
+
+   EXPECT_EQ( m1.getRows(), m2.getRows() );
+   EXPECT_EQ( m1.getColumns(), m2.getColumns() );
+}
+
+template< typename Matrix >
+void test_GetNumberOfNonzeroMatrixElements()
+{
+   using RealType = typename Matrix::RealType;
+   using DeviceType = typename Matrix::DeviceType;
+   using IndexType = typename Matrix::IndexType;
+
+   /*
+    * Sets up the following 10x10 sparse matrix:
+    *
+    /  1  2  4  7                       \ -> 4
+    |  2  3  5  8 10 13 16 19           | -> 8
+    |  4  5  6    11 14       21 25 28  | -> 8
+    |  7  8     9       17 20           | -> 5
+    |    10 11    12          23 26     | -> 5
+    |    13 14       15             29  | -> 4
+    |    16    17       18              | -> 3
+    |    19    20          21           | -> 3
+    |       22    23          24        | -> 3
+    |       25    26             27     | -> 3
+    \       28       29             30  / -> 3
+                                          ----
+                                            49
+    */
+
+   const IndexType rows = 10;
+   const IndexType cols = 10;
+
+   Matrix m( rows, cols, {
+      { 0, 0,  1 },
+      { 1, 0,  2 }, { 1, 1,  3 },
+      { 2, 0,  4 }, { 2, 1,  5 }, {  2, 2,  6 },
+      { 3, 0,  7 }, { 3, 1,  8 },              , { 3, 3,  9 },
+                    { 4, 1, 10 }, {  4, 2, 11 },               { 4, 4, 12 },
+                    { 5, 1, 13 }, {  5, 2, 14 },                              {  5, 5, 15 },
+                    { 6, 1, 16 },                { 6, 3, 17 },                              { 6, 6, 18 },
+                    { 7, 1, 19 },                { 7, 3, 20 },                                            { 7, 7, 21 },
+                                  {  8, 2, 22 },               { 8, 4, 23 },                                           { 8, 8, 24 },
+                                  {  9, 2, 25 },               { 9, 4, 26 },                                                         { 9, 9, 27 }
+                                  { 10, 2, 28 },                              { 10, 4, 29 },                                                      { 10, 10, 30 }
+   } );
+
+   EXPECT_EQ( m.getNumberOfNonzeroMatrixElements(), 49 );
+}
+
+template< typename Matrix >
+void test_Reset()
+{
+   using RealType = typename Matrix::RealType;
+   using DeviceType = typename Matrix::DeviceType;
+   using IndexType = typename Matrix::IndexType;
+
+   /*
+    * Sets up the following 5x4 sparse matrix:
+    *
+    *    /  0  0  0  0 \
+    *    |  0  0  0  0 |
+    *    |  0  0  0  0 |
+    *    |  0  0  0  0 |
+    *    \  0  0  0  0 /
+    */
+
+   const IndexType rows = 5;
+   const IndexType cols = 4;
+
+   Matrix m( rows, cols );
+   m.reset();
+
+   EXPECT_EQ( m.getRows(), 0 );
+   EXPECT_EQ( m.getColumns(), 0 );
+}
+
+template< typename Matrix >
+void test_GetRow()
+{
+   using RealType = typename Matrix::RealType;
+   using DeviceType = typename Matrix::DeviceType;
+   using IndexType = typename Matrix::IndexType;
+   /*
+    * Sets up the following 11x11 sparse matrix:
+    *
+    /  1  2  4  7                       \
+    |  2  3  5  8 10 13 16 19           |
+    |  4  5  6    11 14       22 25 28  |
+    |  7  8     9       17 20           |
+    |    10 11    12          23 26     |
+    |    13 14       15             29  |
+    |    16    17       18              |
+    |    19    20          21           |
+    |       22    23          24        |
+    |       25    26             27     |
+    \       28       29             30  /
+    */
+
+   Matrix m( { 1, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3 }, 11 );
+
+   auto matrixView = m.getView();
+   auto f = [=] __cuda_callable__ ( const IndexType rowIdx ) mutable {
+      auto row = matrixView.getRow( rowIdx );
+      RealType val;
+      switch( rowIdx )
+      {
+         case  0: row.setElement( 0, 0,  1 ); break;
+         case  1: row.setElement( 0, 0,  2 ); row.setElement( 1, 1,  3 ); break;
+         case  2: row.setElement( 0, 0,  4 ); row.setElement( 1, 1,  5 ); row.setElement( 2,  2,  6 ); break;
+         case  3: row.setElement( 0, 0,  7 ); row.setElement( 1, 1,  8 ); row.setElement( 2,  3,  9 ); break;
+         case  4: row.setElement( 0, 1, 10 ); row.setElement( 1, 2, 11 ); row.setElement( 2,  4, 12 ); break;
+         case  5: row.setElement( 0, 1, 13 ); row.setElement( 1, 2, 14 ); row.setElement( 2,  5, 15 ); break;
+         case  6: row.setElement( 0, 1, 16 ); row.setElement( 1, 3, 17 ); row.setElement( 2,  6, 18 ); break;
+         case  7: row.setElement( 0, 1, 19 ); row.setElement( 1, 3, 20 ); row.setElement( 2,  7, 21 ); break;
+         case  8: row.setElement( 0, 2, 22 ); row.setElement( 1, 4, 23 ); row.setElement( 2,  8, 24 ); break;
+         case  9: row.setElement( 0, 2, 25 ); row.setElement( 1, 4, 26 ); row.setElement( 2,  9, 27 ); break;
+         case 10: row.setElement( 0, 2, 28 ); row.setElement( 1, 5, 29 ); row.setElement( 2, 10, 30 ); break;
+      }
+   };
+   TNL::Algorithms::ParallelFor< DeviceType >::exec( ( IndexType ) 0, rows, f );
+
+   EXPECT_EQ( m.getElement( 0,  0 ),  1 );
+   EXPECT_EQ( m.getElement( 0,  1 ),  2 );
+   EXPECT_EQ( m.getElement( 0,  2 ),  4 );
+   EXPECT_EQ( m.getElement( 0,  3 ),  7 );
+   EXPECT_EQ( m.getElement( 0,  4 ),  0 );
+   EXPECT_EQ( m.getElement( 0,  5 ),  0 );
+   EXPECT_EQ( m.getElement( 0,  6 ),  0 );
+   EXPECT_EQ( m.getElement( 0,  7 ),  0 );
+   EXPECT_EQ( m.getElement( 0,  8 ),  0 );
+   EXPECT_EQ( m.getElement( 0,  9 ),  0 );
+   EXPECT_EQ( m.getElement( 0, 10 ),  0 );
+
+   EXPECT_EQ( m.getElement( 1,  0 ),  2 );
+   EXPECT_EQ( m.getElement( 1,  1 ),  3 );
+   EXPECT_EQ( m.getElement( 1,  2 ),  4 );
+   EXPECT_EQ( m.getElement( 1,  3 ),  8 );
+   EXPECT_EQ( m.getElement( 1,  4 ), 10 );
+   EXPECT_EQ( m.getElement( 1,  5 ), 13 );
+   EXPECT_EQ( m.getElement( 1,  6 ), 16 );
+   EXPECT_EQ( m.getElement( 1,  7 ), 19 );
+   EXPECT_EQ( m.getElement( 1,  8 ),  0 );
+   EXPECT_EQ( m.getElement( 1,  9 ),  0 );
+   EXPECT_EQ( m.getElement( 1, 10 ),  0 );
+
+   EXPECT_EQ( m.getElement( 2,  0 ),  4 );
+   EXPECT_EQ( m.getElement( 2,  1 ),  5 );
+   EXPECT_EQ( m.getElement( 2,  2 ),  6 );
+   EXPECT_EQ( m.getElement( 2,  3 ),  0 );
+   EXPECT_EQ( m.getElement( 2,  4 ), 11 );
+   EXPECT_EQ( m.getElement( 2,  5 ), 14 );
+   EXPECT_EQ( m.getElement( 2,  6 ),  0 );
+   EXPECT_EQ( m.getElement( 2,  7 ),  0 );
+   EXPECT_EQ( m.getElement( 2,  8 ), 22 );
+   EXPECT_EQ( m.getElement( 2,  9 ), 25 );
+   EXPECT_EQ( m.getElement( 2, 10 ), 28 );
+
+   EXPECT_EQ( m.getElement( 3,  0 ),  7 );
+   EXPECT_EQ( m.getElement( 3,  1 ),  8 );
+   EXPECT_EQ( m.getElement( 3,  2 ),  0 );
+   EXPECT_EQ( m.getElement( 3,  3 ),  9 );
+   EXPECT_EQ( m.getElement( 3,  4 ),  0 );
+   EXPECT_EQ( m.getElement( 3,  5 ),  0 );
+   EXPECT_EQ( m.getElement( 3,  6 ), 17 );
+   EXPECT_EQ( m.getElement( 3,  7 ), 20 );
+   EXPECT_EQ( m.getElement( 3,  8 ),  0 );
+   EXPECT_EQ( m.getElement( 3,  9 ),  0 );
+   EXPECT_EQ( m.getElement( 3, 10 ),  0 );
+
+   EXPECT_EQ( m.getElement( 4,  0 ),  0 );
+   EXPECT_EQ( m.getElement( 4,  1 ), 10 );
+   EXPECT_EQ( m.getElement( 4,  2 ), 11 );
+   EXPECT_EQ( m.getElement( 4,  3 ),  0 );
+   EXPECT_EQ( m.getElement( 4,  4 ), 12 );
+   EXPECT_EQ( m.getElement( 4,  5 ),  0 );
+   EXPECT_EQ( m.getElement( 4,  6 ),  0 );
+   EXPECT_EQ( m.getElement( 4,  7 ),  0 );
+   EXPECT_EQ( m.getElement( 4,  8 ), 23 );
+   EXPECT_EQ( m.getElement( 4,  9 ), 26 );
+   EXPECT_EQ( m.getElement( 4, 10 ),  0 );
+
+   EXPECT_EQ( m.getElement( 5,  0 ),  0 );
+   EXPECT_EQ( m.getElement( 5,  1 ), 13 );
+   EXPECT_EQ( m.getElement( 5,  2 ), 14 );
+   EXPECT_EQ( m.getElement( 5,  3 ),  0 );
+   EXPECT_EQ( m.getElement( 5,  4 ),  0 );
+   EXPECT_EQ( m.getElement( 5,  5 ), 15 );
+   EXPECT_EQ( m.getElement( 5,  6 ),  0 );
+   EXPECT_EQ( m.getElement( 5,  7 ),  0 );
+   EXPECT_EQ( m.getElement( 5,  8 ),  0 );
+   EXPECT_EQ( m.getElement( 5,  9 ),  0 );
+   EXPECT_EQ( m.getElement( 5, 10 ), 29 );
+
+   EXPECT_EQ( m.getElement( 6,  0 ),  0 );
+   EXPECT_EQ( m.getElement( 6,  1 ), 16 );
+   EXPECT_EQ( m.getElement( 6,  2 ),  0 );
+   EXPECT_EQ( m.getElement( 6,  3 ), 17 );
+   EXPECT_EQ( m.getElement( 6,  4 ),  0 );
+   EXPECT_EQ( m.getElement( 6,  5 ),  0 );
+   EXPECT_EQ( m.getElement( 6,  6 ), 18 );
+   EXPECT_EQ( m.getElement( 6,  7 ),  0 );
+   EXPECT_EQ( m.getElement( 6,  8 ),  0 );
+   EXPECT_EQ( m.getElement( 6,  9 ),  0 );
+   EXPECT_EQ( m.getElement( 6, 10 ),  0 );
+
+   EXPECT_EQ( m.getElement( 7,  0 ),  0 );
+   EXPECT_EQ( m.getElement( 7,  1 ), 19 );
+   EXPECT_EQ( m.getElement( 7,  2 ),  0 );
+   EXPECT_EQ( m.getElement( 7,  3 ), 20 );
+   EXPECT_EQ( m.getElement( 7,  4 ),  0 );
+   EXPECT_EQ( m.getElement( 7,  5 ),  0 );
+   EXPECT_EQ( m.getElement( 7,  6 ),  0 );
+   EXPECT_EQ( m.getElement( 7,  7 ), 21 );
+   EXPECT_EQ( m.getElement( 7,  8 ),  0 );
+   EXPECT_EQ( m.getElement( 7,  9 ),  0 );
+   EXPECT_EQ( m.getElement( 7, 10 ),  0 );
+
+   EXPECT_EQ( m.getElement( 8,  0 ),  0 );
+   EXPECT_EQ( m.getElement( 8,  1 ),  0 );
+   EXPECT_EQ( m.getElement( 8,  2 ), 22 );
+   EXPECT_EQ( m.getElement( 8,  3 ),  0 );
+   EXPECT_EQ( m.getElement( 8,  4 ), 23 );
+   EXPECT_EQ( m.getElement( 8,  5 ),  0 );
+   EXPECT_EQ( m.getElement( 8,  6 ),  0 );
+   EXPECT_EQ( m.getElement( 8,  7 ),  0 );
+   EXPECT_EQ( m.getElement( 8,  8 ), 24 );
+   EXPECT_EQ( m.getElement( 8,  9 ),  0 );
+   EXPECT_EQ( m.getElement( 8, 10 ),  0 );
+
+   EXPECT_EQ( m.getElement( 9,  0 ),  0 );
+   EXPECT_EQ( m.getElement( 9,  1 ),  0 );
+   EXPECT_EQ( m.getElement( 9,  2 ), 25 );
+   EXPECT_EQ( m.getElement( 9,  3 ),  0 );
+   EXPECT_EQ( m.getElement( 9,  4 ), 26 );
+   EXPECT_EQ( m.getElement( 9,  5 ),  0 );
+   EXPECT_EQ( m.getElement( 9,  6 ),  0 );
+   EXPECT_EQ( m.getElement( 9,  7 ),  0 );
+   EXPECT_EQ( m.getElement( 9,  8 ),  0 );
+   EXPECT_EQ( m.getElement( 9,  9 ), 27 );
+   EXPECT_EQ( m.getElement( 9, 10 ),  0 );
+
+   EXPECT_EQ( m.getElement( 10,  0 ),  0 );
+   EXPECT_EQ( m.getElement( 10,  1 ),  0 );
+   EXPECT_EQ( m.getElement( 10,  2 ), 28 );
+   EXPECT_EQ( m.getElement( 10,  3 ),  0 );
+   EXPECT_EQ( m.getElement( 10,  4 ),  0 );
+   EXPECT_EQ( m.getElement( 10,  5 ), 29 );
+   EXPECT_EQ( m.getElement( 10,  6 ),  0 );
+   EXPECT_EQ( m.getElement( 10,  7 ),  0 );
+   EXPECT_EQ( m.getElement( 10,  8 ),  0 );
+   EXPECT_EQ( m.getElement( 10,  9 ),  0 );
+   EXPECT_EQ( m.getElement( 10, 10 ), 30 );
+}
+
+
+template< typename Matrix >
+void test_SetElement()
+{
+   using RealType = typename Matrix::RealType;
+   using DeviceType = typename Matrix::DeviceType;
+   using IndexType = typename Matrix::IndexType;
+
+   /*
+    * Sets up the following 10x10 sparse matrix:
+    *
+    *    /  1  0  0  4  0  0 10  0  0  0  \
+    *    |  0  2  0  5  0  0 11  0  0  0  |
+    *    |  0  0  3  6  0  0 12  0  0  0  |
+    *    |  4  5  6  7  0  0 13  0  0  0  |
+    *    |  0  0  0  0  8  0 14  0  0  0  |
+    *    |  0  0  0  0  0  9 15  0  0  0  |
+    *    | 10 11 12 13 14 15 16  0  0  0  |
+    *    |  0  0  0  0  0  0  0 17  0  0  |
+    *    |  0  0  0  0  0  0  0  0 18  0  |
+    *    \  0  0  0  0  0  0  0  0  0 19 /
+    */
+
+   Matrix m( { 1, 1, 1, 4, 1, 1, 7, 1, 1, 1 }, 10 );
+
+   RealType value = 1;
+   for( IndexType i = 0; i < 4; i++ )
+      m.setElement( i, i, value++ );
+
+   for( IndexType i = 0; i < 4; i++ )
+      m.setElement( 3, i, value++ );
+
+   for( IndexType i = 4; i < 6; i++ )
+      m.setElement( i, i, value++ );
+
+   for( IndexType i = 0; i < 7; i++ )
+      m.setElement( 6, i, value++ );
+
+   for( IndexType i = 7; i < 10; i++ )
+      m.setElement( i, i, value++ );
+
+   EXPECT_EQ( m.getElement( 0, 0 ),  1 );
+   EXPECT_EQ( m.getElement( 0, 1 ),  0 );
+   EXPECT_EQ( m.getElement( 0, 2 ),  0 );
+   EXPECT_EQ( m.getElement( 0, 3 ),  4 );
+   EXPECT_EQ( m.getElement( 0, 4 ),  0 );
+   EXPECT_EQ( m.getElement( 0, 5 ),  0 );
+   EXPECT_EQ( m.getElement( 0, 6 ), 10 );
+   EXPECT_EQ( m.getElement( 0, 7 ),  0 );
+   EXPECT_EQ( m.getElement( 0, 8 ),  0 );
+   EXPECT_EQ( m.getElement( 0, 9 ),  0 );
+
+   EXPECT_EQ( m.getElement( 1, 0 ),  0 );
+   EXPECT_EQ( m.getElement( 1, 1 ),  2 );
+   EXPECT_EQ( m.getElement( 1, 2 ),  0 );
+   EXPECT_EQ( m.getElement( 1, 3 ),  5 );
+   EXPECT_EQ( m.getElement( 1, 4 ),  0 );
+   EXPECT_EQ( m.getElement( 1, 5 ),  0 );
+   EXPECT_EQ( m.getElement( 1, 6 ), 11 );
+   EXPECT_EQ( m.getElement( 1, 7 ),  0 );
+   EXPECT_EQ( m.getElement( 1, 8 ),  0 );
+   EXPECT_EQ( m.getElement( 1, 9 ),  0 );
+
+   EXPECT_EQ( m.getElement( 2, 0 ),  0 );
+   EXPECT_EQ( m.getElement( 2, 1 ),  0 );
+   EXPECT_EQ( m.getElement( 2, 2 ),  3 );
+   EXPECT_EQ( m.getElement( 2, 3 ),  6 );
+   EXPECT_EQ( m.getElement( 2, 4 ),  0 );
+   EXPECT_EQ( m.getElement( 2, 5 ),  0 );
+   EXPECT_EQ( m.getElement( 2, 6 ), 12 );
+   EXPECT_EQ( m.getElement( 2, 7 ),  0 );
+   EXPECT_EQ( m.getElement( 2, 8 ),  0 );
+   EXPECT_EQ( m.getElement( 2, 9 ),  0 );
+
+   EXPECT_EQ( m.getElement( 3, 0 ),  4 );
+   EXPECT_EQ( m.getElement( 3, 1 ),  5 );
+   EXPECT_EQ( m.getElement( 3, 2 ),  6 );
+   EXPECT_EQ( m.getElement( 3, 3 ),  7 );
+   EXPECT_EQ( m.getElement( 3, 4 ),  0 );
+   EXPECT_EQ( m.getElement( 3, 5 ),  0 );
+   EXPECT_EQ( m.getElement( 3, 6 ), 13 );
+   EXPECT_EQ( m.getElement( 3, 7 ),  0 );
+   EXPECT_EQ( m.getElement( 3, 8 ),  0 );
+   EXPECT_EQ( m.getElement( 3, 9 ),  0 );
+
+   EXPECT_EQ( m.getElement( 4, 0 ),  0 );
+   EXPECT_EQ( m.getElement( 4, 1 ),  0 );
+   EXPECT_EQ( m.getElement( 4, 2 ),  0 );
+   EXPECT_EQ( m.getElement( 4, 3 ),  0 );
+   EXPECT_EQ( m.getElement( 4, 4 ),  8 );
+   EXPECT_EQ( m.getElement( 4, 5 ),  0 );
+   EXPECT_EQ( m.getElement( 4, 6 ), 14 );
+   EXPECT_EQ( m.getElement( 4, 7 ),  0 );
+   EXPECT_EQ( m.getElement( 4, 8 ),  0 );
+   EXPECT_EQ( m.getElement( 4, 9 ),  0 );
+
+   EXPECT_EQ( m.getElement( 5, 0 ),  0 );
+   EXPECT_EQ( m.getElement( 5, 1 ),  0 );
+   EXPECT_EQ( m.getElement( 5, 2 ),  0 );
+   EXPECT_EQ( m.getElement( 5, 3 ),  0 );
+   EXPECT_EQ( m.getElement( 5, 4 ),  0 );
+   EXPECT_EQ( m.getElement( 5, 5 ),  9 );
+   EXPECT_EQ( m.getElement( 5, 6 ), 15 );
+   EXPECT_EQ( m.getElement( 5, 7 ),  0 );
+   EXPECT_EQ( m.getElement( 5, 8 ),  0 );
+   EXPECT_EQ( m.getElement( 5, 9 ),  0 );
+
+   EXPECT_EQ( m.getElement( 6, 0 ), 10 );
+   EXPECT_EQ( m.getElement( 6, 1 ), 11 );
+   EXPECT_EQ( m.getElement( 6, 2 ), 12 );
+   EXPECT_EQ( m.getElement( 6, 3 ), 13 );
+   EXPECT_EQ( m.getElement( 6, 4 ), 14 );
+   EXPECT_EQ( m.getElement( 6, 5 ), 15 );
+   EXPECT_EQ( m.getElement( 6, 6 ), 16 );
+   EXPECT_EQ( m.getElement( 6, 7 ),  0 );
+   EXPECT_EQ( m.getElement( 6, 8 ),  0 );
+   EXPECT_EQ( m.getElement( 6, 9 ),  0 );
+
+   EXPECT_EQ( m.getElement( 7, 0 ),  0 );
+   EXPECT_EQ( m.getElement( 7, 1 ),  0 );
+   EXPECT_EQ( m.getElement( 7, 2 ),  0 );
+   EXPECT_EQ( m.getElement( 7, 3 ),  0 );
+   EXPECT_EQ( m.getElement( 7, 4 ),  0 );
+   EXPECT_EQ( m.getElement( 7, 5 ),  0 );
+   EXPECT_EQ( m.getElement( 7, 6 ),  0 );
+   EXPECT_EQ( m.getElement( 7, 7 ), 17 );
+   EXPECT_EQ( m.getElement( 7, 8 ),  0 );
+   EXPECT_EQ( m.getElement( 7, 9 ),  0 );
+
+   EXPECT_EQ( m.getElement( 8, 0 ),  0 );
+   EXPECT_EQ( m.getElement( 8, 1 ),  0 );
+   EXPECT_EQ( m.getElement( 8, 2 ),  0 );
+   EXPECT_EQ( m.getElement( 8, 3 ),  0 );
+   EXPECT_EQ( m.getElement( 8, 4 ),  0 );
+   EXPECT_EQ( m.getElement( 8, 5 ),  0 );
+   EXPECT_EQ( m.getElement( 8, 6 ),  0 );
+   EXPECT_EQ( m.getElement( 8, 7 ),  0 );
+   EXPECT_EQ( m.getElement( 8, 8 ), 18 );
+   EXPECT_EQ( m.getElement( 8, 9 ),  0 );
+
+   EXPECT_EQ( m.getElement( 9, 0 ),  0 );
+   EXPECT_EQ( m.getElement( 9, 1 ),  0 );
+   EXPECT_EQ( m.getElement( 9, 2 ),  0 );
+   EXPECT_EQ( m.getElement( 9, 3 ),  0 );
+   EXPECT_EQ( m.getElement( 9, 4 ),  0 );
+   EXPECT_EQ( m.getElement( 9, 5 ),  0 );
+   EXPECT_EQ( m.getElement( 9, 6 ),  0 );
+   EXPECT_EQ( m.getElement( 9, 7 ),  0 );
+   EXPECT_EQ( m.getElement( 9, 8 ),  0 );
+   EXPECT_EQ( m.getElement( 9, 9 ), 19 );
+}
+
+template< typename Matrix >
+void test_AddElement()
+{
+   using RealType = typename Matrix::RealType;
+   using DeviceType = typename Matrix::DeviceType;
+   using IndexType = typename Matrix::IndexType;
+
+   /*
+    * Sets up the following 6x5 sparse matrix:
+    *
+    *    /  1  2  0  0  0 \
+    *    |  2  3  4  0  0 |
+    *    |  0  4  5  6  0 |
+    *    |  0  0  6  7  8 |
+    *    |  0  0  0  8  9 |
+    *    \  0  0  0  0 10 /
+    */
+
+   const IndexType rows = 6;
+   const IndexType cols = 5;
+
+   Matrix m( 6, 5, {
+      { 0, 0, 1 }, 
+      { 1, 0, 2 }, { 1, 1, 3 },
+                   { 2, 1, 4 }, { 2, 2, 5 },
+                                { 3, 2, 6 }, { 3, 3, 7 },
+                                             { 4, 3, 8 }, { 4, 4,  9 },
+                                                          { 5, 5, 10 } } );
+
+   // Check the set elements
+   EXPECT_EQ( m.getElement( 0, 0 ),  1 );
+   EXPECT_EQ( m.getElement( 0, 1 ),  2 );
+   EXPECT_EQ( m.getElement( 0, 2 ),  0 );
+   EXPECT_EQ( m.getElement( 0, 3 ),  0 );
+   EXPECT_EQ( m.getElement( 0, 4 ),  0 );
+
+   EXPECT_EQ( m.getElement( 1, 0 ),  2 );
+   EXPECT_EQ( m.getElement( 1, 1 ),  3 );
+   EXPECT_EQ( m.getElement( 1, 2 ),  4 );
+   EXPECT_EQ( m.getElement( 1, 3 ),  0 );
+   EXPECT_EQ( m.getElement( 1, 4 ),  0 );
+
+   EXPECT_EQ( m.getElement( 2, 0 ),  0 );
+   EXPECT_EQ( m.getElement( 2, 1 ),  4 );
+   EXPECT_EQ( m.getElement( 2, 2 ),  5 );
+   EXPECT_EQ( m.getElement( 2, 3 ),  6 );
+   EXPECT_EQ( m.getElement( 2, 4 ),  0 );
+
+   EXPECT_EQ( m.getElement( 3, 0 ),  0 );
+   EXPECT_EQ( m.getElement( 3, 1 ),  0 );
+   EXPECT_EQ( m.getElement( 3, 2 ),  6 );
+   EXPECT_EQ( m.getElement( 3, 3 ),  7 );
+   EXPECT_EQ( m.getElement( 3, 4 ),  8 );
+
+   EXPECT_EQ( m.getElement( 4, 0 ),  0 );
+   EXPECT_EQ( m.getElement( 4, 1 ),  0 );
+   EXPECT_EQ( m.getElement( 4, 2 ),  0 );
+   EXPECT_EQ( m.getElement( 4, 3 ),  8 );
+   EXPECT_EQ( m.getElement( 4, 4 ),  9 );
+
+   EXPECT_EQ( m.getElement( 5, 0 ),  0 );
+   EXPECT_EQ( m.getElement( 5, 1 ),  0 );
+   EXPECT_EQ( m.getElement( 5, 2 ),  0 );
+   EXPECT_EQ( m.getElement( 5, 3 ),  0 );
+   EXPECT_EQ( m.getElement( 5, 4 ), 10 );
+############################################################################
+   // Add new elements to the old elements with a multiplying factor applied to the old elements.
+   /*
+    * The following setup results in the following 6x5 sparse matrix:
+    *
+    *    /  3  6  9  0  0 \
+    *    |  0 12 15 18  0 |
+    *    |  0  0 21 24 27 |
+    *    | 30 11 12  0  0 |
+    *    |  0 35 14 15  0 |
+    *    \  0  0 16 41 18 /
+    */
+
+   RealType newValue = 1;
+   for( IndexType i = 0; i < cols - 2; i++ )         // 0th row
+      m.addElement( 0, i, newValue++, 2.0 );
+
+   for( IndexType i = 1; i < cols - 1; i++ )         // 1st row
+      m.addElement( 1, i, newValue++, 2.0 );
+
+   for( IndexType i = 2; i < cols; i++ )             // 2nd row
+      m.addElement( 2, i, newValue++, 2.0 );
+
+   for( IndexType i = 0; i < cols - 2; i++ )         // 3rd row
+      m.addElement( 3, i, newValue++, 2.0 );
+
+   for( IndexType i = 1; i < cols - 1; i++ )         // 4th row
+      m.addElement( 4, i, newValue++, 2.0 );
+
+   for( IndexType i = 2; i < cols; i++ )             // 5th row
+      m.addElement( 5, i, newValue++, 2.0 );
+
+
+   EXPECT_EQ( m.getElement( 0, 0 ),  3 );
+   EXPECT_EQ( m.getElement( 0, 1 ),  6 );
+   EXPECT_EQ( m.getElement( 0, 2 ),  9 );
+   EXPECT_EQ( m.getElement( 0, 3 ),  0 );
+   EXPECT_EQ( m.getElement( 0, 4 ),  0 );
+
+   EXPECT_EQ( m.getElement( 1, 0 ),  0 );
+   EXPECT_EQ( m.getElement( 1, 1 ), 12 );
+   EXPECT_EQ( m.getElement( 1, 2 ), 15 );
+   EXPECT_EQ( m.getElement( 1, 3 ), 18 );
+   EXPECT_EQ( m.getElement( 1, 4 ),  0 );
+
+   EXPECT_EQ( m.getElement( 2, 0 ),  0 );
+   EXPECT_EQ( m.getElement( 2, 1 ),  0 );
+   EXPECT_EQ( m.getElement( 2, 2 ), 21 );
+   EXPECT_EQ( m.getElement( 2, 3 ), 24 );
+   EXPECT_EQ( m.getElement( 2, 4 ), 27 );
+
+   EXPECT_EQ( m.getElement( 3, 0 ), 30 );
+   EXPECT_EQ( m.getElement( 3, 1 ), 11 );
+   EXPECT_EQ( m.getElement( 3, 2 ), 12 );
+   EXPECT_EQ( m.getElement( 3, 3 ),  0 );
+   EXPECT_EQ( m.getElement( 3, 4 ),  0 );
+
+   EXPECT_EQ( m.getElement( 4, 0 ),  0 );
+   EXPECT_EQ( m.getElement( 4, 1 ), 35 );
+   EXPECT_EQ( m.getElement( 4, 2 ), 14 );
+   EXPECT_EQ( m.getElement( 4, 3 ), 15 );
+   EXPECT_EQ( m.getElement( 4, 4 ),  0 );
+
+   EXPECT_EQ( m.getElement( 5, 0 ),  0 );
+   EXPECT_EQ( m.getElement( 5, 1 ),  0 );
+   EXPECT_EQ( m.getElement( 5, 2 ), 16 );
+   EXPECT_EQ( m.getElement( 5, 3 ), 41 );
+   EXPECT_EQ( m.getElement( 5, 4 ), 18 );
+}
+
+template< typename Matrix >
+void test_VectorProduct()
+{
+   using RealType = typename Matrix::RealType;
+   using DeviceType = typename Matrix::DeviceType;
+   using IndexType = typename Matrix::IndexType;
+   using VectorType = TNL::Containers::Vector< RealType, DeviceType, IndexType >;
+
+   /*
+    * Sets up the following 4x4 sparse matrix:
+    *
+    *    /  1  0  0  0 \
+    *    |  0  2  0  3 |
+    *    |  0  4  0  0 |
+    *    \  0  0  5  0 /
+    */
+
+   const IndexType m_rows_1 = 4;
+   const IndexType m_cols_1 = 4;
+
+   Matrix m_1;
+   m_1.reset();
+   m_1.setDimensions( m_rows_1, m_cols_1 );
+   typename Matrix::CompressedRowLengthsVector rowLengths_1;
+   rowLengths_1.setSize( m_rows_1 );
+   rowLengths_1.setElement( 0, 1 );
+   rowLengths_1.setElement( 1, 2 );
+   rowLengths_1.setElement( 2, 1 );
+   rowLengths_1.setElement( 3, 1 );
+   m_1.setCompressedRowLengths( rowLengths_1 );
+
+   RealType value_1 = 1;
+   m_1.setElement( 0, 0, value_1++ );      // 0th row
+
+   m_1.setElement( 1, 1, value_1++ );      // 1st row
+   m_1.setElement( 1, 3, value_1++ );
+
+   m_1.setElement( 2, 1, value_1++ );      // 2nd row
+
+   m_1.setElement( 3, 2, value_1++ );      // 3rd row
+
+   VectorType inVector_1;
+   inVector_1.setSize( m_cols_1 );
+   for( IndexType i = 0; i < inVector_1.getSize(); i++ )
+       inVector_1.setElement( i, 2 );
+
+   VectorType outVector_1;
+   outVector_1.setSize( m_rows_1 );
+   for( IndexType j = 0; j < outVector_1.getSize(); j++ )
+       outVector_1.setElement( j, 0 );
+
+
+   m_1.vectorProduct( inVector_1, outVector_1 );
+
+
+   EXPECT_EQ( outVector_1.getElement( 0 ),  2 );
+   EXPECT_EQ( outVector_1.getElement( 1 ), 10 );
+   EXPECT_EQ( outVector_1.getElement( 2 ),  8 );
+   EXPECT_EQ( outVector_1.getElement( 3 ), 10 );
+
+   /*
+    * Sets up the following 4x4 sparse matrix:
+    *
+    *    /  1  2  3  0 \
+    *    |  0  0  0  4 |
+    *    |  5  6  7  0 |
+    *    \  0  8  0  0 /
+    */
+
+   const IndexType m_rows_2 = 4;
+   const IndexType m_cols_2 = 4;
+
+   Matrix m_2( m_rows_2, m_cols_2 );
+   typename Matrix::CompressedRowLengthsVector rowLengths_2{ 3, 1, 3, 1 };
+   /*rowLengths_2 = 3;
+   rowLengths_2.setElement( 1, 1 );
+   rowLengths_2.setElement( 3, 1 );*/
+   m_2.setCompressedRowLengths( rowLengths_2 );
+
+   RealType value_2 = 1;
+   for( IndexType i = 0; i < 3; i++ )   // 0th row
+      m_2.setElement( 0, i, value_2++ );
+
+   m_2.setElement( 1, 3, value_2++ );      // 1st row
+
+   for( IndexType i = 0; i < 3; i++ )   // 2nd row
+      m_2.setElement( 2, i, value_2++ );
+
+   for( IndexType i = 1; i < 2; i++ )       // 3rd row
+      m_2.setElement( 3, i, value_2++ );
+
+   VectorType inVector_2;
+   inVector_2.setSize( m_cols_2 );
+   for( IndexType i = 0; i < inVector_2.getSize(); i++ )
+      inVector_2.setElement( i, 2 );
+
+   VectorType outVector_2;
+   outVector_2.setSize( m_rows_2 );
+   for( IndexType j = 0; j < outVector_2.getSize(); j++ )
+      outVector_2.setElement( j, 0 );
+
+   m_2.vectorProduct( inVector_2, outVector_2 );
+
+   EXPECT_EQ( outVector_2.getElement( 0 ), 12 );
+   EXPECT_EQ( outVector_2.getElement( 1 ),  8 );
+   EXPECT_EQ( outVector_2.getElement( 2 ), 36 );
+   EXPECT_EQ( outVector_2.getElement( 3 ), 16 );
+
+   /*
+    * Sets up the following 4x4 sparse matrix:
+    *
+    *    /  1  2  3  0 \
+    *    |  0  4  5  6 |
+    *    |  7  8  9  0 |
+    *    \  0 10 11 12 /
+    */
+
+   const IndexType m_rows_3 = 4;
+   const IndexType m_cols_3 = 4;
+
+   Matrix m_3( m_rows_3, m_cols_3 );
+   typename Matrix::CompressedRowLengthsVector rowLengths_3{ 3, 3, 3, 3 };
+   m_3.setCompressedRowLengths( rowLengths_3 );
+
+   RealType value_3 = 1;
+   for( IndexType i = 0; i < 3; i++ )          // 0th row
+      m_3.setElement( 0, i, value_3++ );
+
+   for( IndexType i = 1; i < 4; i++ )
+      m_3.setElement( 1, i, value_3++ );      // 1st row
+
+   for( IndexType i = 0; i < 3; i++ )          // 2nd row
+      m_3.setElement( 2, i, value_3++ );
+
+   for( IndexType i = 1; i < 4; i++ )          // 3rd row
+      m_3.setElement( 3, i, value_3++ );
+
+   VectorType inVector_3;
+   inVector_3.setSize( m_cols_3 );
+   for( IndexType i = 0; i < inVector_3.getSize(); i++ )
+      inVector_3.setElement( i, 2 );
+
+   VectorType outVector_3;
+   outVector_3.setSize( m_rows_3 );
+   for( IndexType j = 0; j < outVector_3.getSize(); j++ )
+      outVector_3.setElement( j, 0 );
+
+   m_3.vectorProduct( inVector_3, outVector_3 );
+
+   EXPECT_EQ( outVector_3.getElement( 0 ), 12 );
+   EXPECT_EQ( outVector_3.getElement( 1 ), 30 );
+   EXPECT_EQ( outVector_3.getElement( 2 ), 48 );
+   EXPECT_EQ( outVector_3.getElement( 3 ), 66 );
+
+   /*
+    * Sets up the following 8x8 sparse matrix:
+    *
+    *    /  1  2  3  0  0  4  0  0 \
+    *    |  0  5  6  7  8  0  0  0 |
+    *    |  9 10 11 12 13  0  0  0 |
+    *    |  0 14 15 16 17  0  0  0 |
+    *    |  0  0 18 19 20 21  0  0 |
+    *    |  0  0  0 22 23 24 25  0 |
+    *    | 26 27 28 29 30  0  0  0 |
+    *    \ 31 32 33 34 35  0  0  0 /
+    */
+
+   const IndexType m_rows_4 = 8;
+   const IndexType m_cols_4 = 8;
+
+   Matrix m_4( m_rows_4, m_cols_4 );
+   typename Matrix::CompressedRowLengthsVector rowLengths_4{ 4, 4, 5, 4, 4, 4, 5, 5 };
+   /*rowLengths_4.setSize( m_rows_4 );
+   rowLengths_4.setValue( 4 );
+   rowLengths_4.setElement( 2, 5 );
+   rowLengths_4.setElement( 6, 5 );
+   rowLengths_4.setElement( 7, 5 );*/
+   m_4.setCompressedRowLengths( rowLengths_4 );
+
+   RealType value_4 = 1;
+   for( IndexType i = 0; i < 3; i++ )       // 0th row
+      m_4.setElement( 0, i, value_4++ );
+
+   m_4.setElement( 0, 5, value_4++ );
+
+   for( IndexType i = 1; i < 5; i++ )       // 1st row
+      m_4.setElement( 1, i, value_4++ );
+
+   for( IndexType i = 0; i < 5; i++ )       // 2nd row
+      m_4.setElement( 2, i, value_4++ );
+
+   for( IndexType i = 1; i < 5; i++ )       // 3rd row
+      m_4.setElement( 3, i, value_4++ );
+
+   for( IndexType i = 2; i < 6; i++ )       // 4th row
+      m_4.setElement( 4, i, value_4++ );
+
+   for( IndexType i = 3; i < 7; i++ )       // 5th row
+      m_4.setElement( 5, i, value_4++ );
+
+   for( IndexType i = 0; i < 5; i++ )       // 6th row
+      m_4.setElement( 6, i, value_4++ );
+
+   for( IndexType i = 0; i < 5; i++ )       // 7th row
+      m_4.setElement( 7, i, value_4++ );
+
+   VectorType inVector_4;
+   inVector_4.setSize( m_cols_4 );
+   for( IndexType i = 0; i < inVector_4.getSize(); i++ )
+      inVector_4.setElement( i, 2 );
+
+   VectorType outVector_4;
+   outVector_4.setSize( m_rows_4 );
+   for( IndexType j = 0; j < outVector_4.getSize(); j++ )
+      outVector_4.setElement( j, 0 );
+
+   m_4.vectorProduct( inVector_4, outVector_4 );
+
+   EXPECT_EQ( outVector_4.getElement( 0 ),  20 );
+   EXPECT_EQ( outVector_4.getElement( 1 ),  52 );
+   EXPECT_EQ( outVector_4.getElement( 2 ), 110 );
+   EXPECT_EQ( outVector_4.getElement( 3 ), 124 );
+   EXPECT_EQ( outVector_4.getElement( 4 ), 156 );
+   EXPECT_EQ( outVector_4.getElement( 5 ), 188 );
+   EXPECT_EQ( outVector_4.getElement( 6 ), 280 );
+   EXPECT_EQ( outVector_4.getElement( 7 ), 330 );
+
+
+   /*
+    * Sets up the following 8x8 sparse matrix:
+    *
+    *    /  1  2  3  0  4  5  0  1 \   6
+    *    |  0  6  0  7  0  0  0  1 |   3
+    *    |  0  8  9  0 10  0  0  1 |   4
+    *    |  0 11 12 13 14  0  0  1 |   5
+    *    |  0 15  0  0  0  0  0  1 |   2
+    *    |  0 16 17 18 19 20 21  1 |   7
+    *    | 22 23 24 25 26 27 28  1 |   8
+    *    \ 29 30 31 32 33 34 35 36 /   8
+    */
+
+   const IndexType m_rows_5 = 8;
+   const IndexType m_cols_5 = 8;
+
+   Matrix m_5( m_rows_5, m_cols_5 );
+   typename Matrix::CompressedRowLengthsVector rowLengths_5{ 6, 3, 4, 5, 2, 7, 8, 8 };
+   m_5.setCompressedRowLengths( rowLengths_5 );
+
+   RealType value_5 = 1;
+   for( IndexType i = 0; i < 3; i++ )   // 0th row
+      m_5.setElement( 0, i, value_5++ );
+
+   m_5.setElement( 0, 4, value_5++ );           // 0th row
+   m_5.setElement( 0, 5, value_5++ );
+
+   m_5.setElement( 1, 1, value_5++ );           // 1st row
+   m_5.setElement( 1, 3, value_5++ );
+
+   for( IndexType i = 1; i < 3; i++ )            // 2nd row
+      m_5.setElement( 2, i, value_5++ );
+
+   m_5.setElement( 2, 4, value_5++ );           // 2nd row
+
+   for( IndexType i = 1; i < 5; i++ )            // 3rd row
+      m_5.setElement( 3, i, value_5++ );
+
+   m_5.setElement( 4, 1, value_5++ );           // 4th row
+
+   for( IndexType i = 1; i < 7; i++ )            // 5th row
+      m_5.setElement( 5, i, value_5++ );
+
+   for( IndexType i = 0; i < 7; i++ )            // 6th row
+      m_5.setElement( 6, i, value_5++ );
+
+   for( IndexType i = 0; i < 8; i++ )            // 7th row
+      m_5.setElement( 7, i, value_5++ );
+
+   for( IndexType i = 0; i < 7; i++ )            // 1s at the end of rows
+      m_5.setElement( i, 7, 1);
+
+   VectorType inVector_5;
+   inVector_5.setSize( m_cols_5 );
+   for( IndexType i = 0; i < inVector_5.getSize(); i++ )
+       inVector_5.setElement( i, 2 );
+
+   VectorType outVector_5;
+   outVector_5.setSize( m_rows_5 );
+   for( IndexType j = 0; j < outVector_5.getSize(); j++ )
+       outVector_5.setElement( j, 0 );
+
+   m_5.vectorProduct( inVector_5, outVector_5 );
+
+   EXPECT_EQ( outVector_5.getElement( 0 ),  32 );
+   EXPECT_EQ( outVector_5.getElement( 1 ),  28 );
+   EXPECT_EQ( outVector_5.getElement( 2 ),  56 );
+   EXPECT_EQ( outVector_5.getElement( 3 ), 102 );
+   EXPECT_EQ( outVector_5.getElement( 4 ),  32 );
+   EXPECT_EQ( outVector_5.getElement( 5 ), 224 );
+   EXPECT_EQ( outVector_5.getElement( 6 ), 352 );
+   EXPECT_EQ( outVector_5.getElement( 7 ), 520 );
+}
+
+template< typename Matrix >
+void test_RowsReduction()
+{
+   using RealType = typename Matrix::RealType;
+   using DeviceType = typename Matrix::DeviceType;
+   using IndexType = typename Matrix::IndexType;
+
+   /*
+    * Sets up the following 8x8 sparse matrix:
+    *
+    *    /  1  2  3  0  4  5  0  1 \   6
+    *    |  0  6  0  7  0  0  0  1 |   3
+    *    |  0  8  9  0 10  0  0  1 |   4
+    *    |  0 11 12 13 14  0  0  1 |   5
+    *    |  0 15  0  0  0  0  0  1 |   2
+    *    |  0 16 17 18 19 20 21  1 |   7
+    *    | 22 23 24 25 26 27 28  1 |   8
+    *    \ 29 30 31 32 33 34 35 36 /   8
+    */
+
+   const IndexType rows = 8;
+   const IndexType cols = 8;
+
+   Matrix m;
+   m.setDimensions( rows, cols );
+   typename Matrix::RowsCapacitiesType rowsCapacities{ 6, 3, 4, 5, 2, 7, 8, 8 };
+   m.setCompressedRowLengths( rowsCapacities );
+
+   RealType value = 1;
+   for( IndexType i = 0; i < 3; i++ )   // 0th row
+      m.setElement( 0, i, value++ );
+
+   m.setElement( 0, 4, value++ );       // 0th row
+   m.setElement( 0, 5, value++ );
+
+   m.setElement( 1, 1, value++ );       // 1st row
+   m.setElement( 1, 3, value++ );
+
+   for( IndexType i = 1; i < 3; i++ )   // 2nd row
+      m.setElement( 2, i, value++ );
+
+   m.setElement( 2, 4, value++ );       // 2nd row
+
+   for( IndexType i = 1; i < 5; i++ )   // 3rd row
+      m.setElement( 3, i, value++ );
+
+   m.setElement( 4, 1, value++ );       // 4th row
+
+   for( IndexType i = 1; i < 7; i++ )   // 5th row
+      m.setElement( 5, i, value++ );
+
+   for( IndexType i = 0; i < 7; i++ )   // 6th row
+      m.setElement( 6, i, value++ );
+
+   for( IndexType i = 0; i < 8; i++ )   // 7th row
+       m.setElement( 7, i, value++ );
+
+   for( IndexType i = 0; i < 7; i++ )   // 1s at the end of rows
+      m.setElement( i, 7, 1);
+
+   ////
+   // Compute number of non-zero elements in rows.
+   typename Matrix::RowsCapacitiesType rowLengths( rows );
+   auto rowLengths_view = rowLengths.getView();
+   auto fetch = [] __cuda_callable__ ( IndexType row, IndexType column, IndexType globalIdx, const RealType& value ) -> IndexType {
+      return ( value != 0.0 );
+   };
+   auto reduce = [] __cuda_callable__ ( IndexType& aux, const IndexType a ) {
+      aux += a;
+   };
+   auto keep = [=] __cuda_callable__ ( const IndexType rowIdx, const IndexType value ) mutable {
+      rowLengths_view[ rowIdx ] = value;
+   };
+   m.allRowsReduction( fetch, reduce, keep, 0 );
+   EXPECT_EQ( rowsCapacities, rowLengths );
+   m.getCompressedRowLengths( rowLengths );
+   EXPECT_EQ( rowsCapacities, rowLengths );
+
+   ////
+   // Compute max norm
+   TNL::Containers::Vector< RealType, DeviceType, IndexType > rowSums( rows );
+   auto rowSums_view = rowSums.getView();
+   auto max_fetch = [] __cuda_callable__ ( IndexType row, IndexType column, IndexType globalIdx, const RealType& value ) -> IndexType {
+      return abs( value );
+   };
+   auto max_reduce = [] __cuda_callable__ ( IndexType& aux, const IndexType a ) {
+      aux += a;
+   };
+   auto max_keep = [=] __cuda_callable__ ( const IndexType rowIdx, const IndexType value ) mutable {
+      rowSums_view[ rowIdx ] = value;
+   };
+   m.allRowsReduction( max_fetch, max_reduce, max_keep, 0 );
+   const RealType maxNorm = TNL::max( rowSums );
+   EXPECT_EQ( maxNorm, 260 ) ; // 29+30+31+32+33+34+35+36
+}
+
+template< typename Matrix >
+void test_PerformSORIteration()
+{
+   using RealType = typename Matrix::RealType;
+   using DeviceType = typename Matrix::DeviceType;
+   using IndexType = typename Matrix::IndexType;
+
+   /*
+    * Sets up the following 4x4 sparse matrix:
+    *
+    *    /  4  1  0  0 \
+    *    |  1  4  1  0 |
+    *    |  0  1  4  1 |
+    *    \  0  0  1  4 /
+    */
+
+   const IndexType m_rows = 4;
+   const IndexType m_cols = 4;
+
+   Matrix m( m_rows, m_cols );
+   typename Matrix::CompressedRowLengthsVector rowLengths( m_rows );
+   rowLengths = 3;
+   m.setCompressedRowLengths( rowLengths );
+
+   m.setElement( 0, 0, 4.0 );        // 0th row
+   m.setElement( 0, 1, 1.0);
+
+   m.setElement( 1, 0, 1.0 );        // 1st row
+   m.setElement( 1, 1, 4.0 );
+   m.setElement( 1, 2, 1.0 );
+
+   m.setElement( 2, 1, 1.0 );        // 2nd row
+   m.setElement( 2, 2, 4.0 );
+   m.setElement( 2, 3, 1.0 );
+
+   m.setElement( 3, 2, 1.0 );        // 3rd row
+   m.setElement( 3, 3, 4.0 );
+
+   RealType bVector [ 4 ] = { 1, 1, 1, 1 };
+   RealType xVector [ 4 ] = { 1, 1, 1, 1 };
+
+   IndexType row = 0;
+   RealType omega = 1;
+
+   m.performSORIteration( bVector, row++, xVector, omega);
+
+   EXPECT_EQ( xVector[ 0 ], 0.0 );
+   EXPECT_EQ( xVector[ 1 ], 1.0 );
+   EXPECT_EQ( xVector[ 2 ], 1.0 );
+   EXPECT_EQ( xVector[ 3 ], 1.0 );
+
+   m.performSORIteration( bVector, row++, xVector, omega);
+
+   EXPECT_EQ( xVector[ 0 ], 0.0 );
+   EXPECT_EQ( xVector[ 1 ], 0.0 );
+   EXPECT_EQ( xVector[ 2 ], 1.0 );
+   EXPECT_EQ( xVector[ 3 ], 1.0 );
+
+   m.performSORIteration( bVector, row++, xVector, omega);
+
+   EXPECT_EQ( xVector[ 0 ], 0.0 );
+   EXPECT_EQ( xVector[ 1 ], 0.0 );
+   EXPECT_EQ( xVector[ 2 ], 0.0 );
+   EXPECT_EQ( xVector[ 3 ], 1.0 );
+
+   m.performSORIteration( bVector, row++, xVector, omega);
+
+   EXPECT_EQ( xVector[ 0 ], 0.0 );
+   EXPECT_EQ( xVector[ 1 ], 0.0 );
+   EXPECT_EQ( xVector[ 2 ], 0.0 );
+   EXPECT_EQ( xVector[ 3 ], 0.25 );
+}
+
+template< typename Matrix >
+void test_SaveAndLoad( const char* filename )
+{
+   using RealType = typename Matrix::RealType;
+   using DeviceType = typename Matrix::DeviceType;
+   using IndexType = typename Matrix::IndexType;
+
+   /*
+    * Sets up the following 4x4 sparse matrix:
+    *
+    *    /  1  2  3  0 \
+    *    |  0  4  0  5 |
+    *    |  6  7  8  0 |
+    *    \  0  9 10 11 /
+    */
+
+   const IndexType m_rows = 4;
+   const IndexType m_cols = 4;
+
+   Matrix savedMatrix( m_rows, m_cols );
+   typename Matrix::CompressedRowLengthsVector rowLengths( m_rows );
+   rowLengths = 3;
+   savedMatrix.setCompressedRowLengths( rowLengths );
+
+   RealType value = 1;
+   for( IndexType i = 0; i < m_cols - 1; i++ )   // 0th row
+      savedMatrix.setElement( 0, i, value++ );
+
+   savedMatrix.setElement( 1, 1, value++ );
+   savedMatrix.setElement( 1, 3, value++ );      // 1st row
+
+   for( IndexType i = 0; i < m_cols - 1; i++ )   // 2nd row
+      savedMatrix.setElement( 2, i, value++ );
+
+   for( IndexType i = 1; i < m_cols; i++ )       // 3rd row
+      savedMatrix.setElement( 3, i, value++ );
+
+   ASSERT_NO_THROW( savedMatrix.save( filename ) );
+
+   Matrix loadedMatrix( m_rows, m_cols );
+   typename Matrix::CompressedRowLengthsVector rowLengths2( m_rows );
+   rowLengths2 = 3;
+   loadedMatrix.setCompressedRowLengths( rowLengths2 );
+
+   ASSERT_NO_THROW( loadedMatrix.load( filename ) );
+
+   EXPECT_EQ( savedMatrix.getElement( 0, 0 ), loadedMatrix.getElement( 0, 0 ) );
+   EXPECT_EQ( savedMatrix.getElement( 0, 1 ), loadedMatrix.getElement( 0, 1 ) );
+   EXPECT_EQ( savedMatrix.getElement( 0, 2 ), loadedMatrix.getElement( 0, 2 ) );
+   EXPECT_EQ( savedMatrix.getElement( 0, 3 ), loadedMatrix.getElement( 0, 3 ) );
+
+   EXPECT_EQ( savedMatrix.getElement( 1, 0 ), loadedMatrix.getElement( 1, 0 ) );
+   EXPECT_EQ( savedMatrix.getElement( 1, 1 ), loadedMatrix.getElement( 1, 1 ) );
+   EXPECT_EQ( savedMatrix.getElement( 1, 2 ), loadedMatrix.getElement( 1, 2 ) );
+   EXPECT_EQ( savedMatrix.getElement( 1, 3 ), loadedMatrix.getElement( 1, 3 ) );
+
+   EXPECT_EQ( savedMatrix.getElement( 2, 0 ), loadedMatrix.getElement( 2, 0 ) );
+   EXPECT_EQ( savedMatrix.getElement( 2, 1 ), loadedMatrix.getElement( 2, 1 ) );
+   EXPECT_EQ( savedMatrix.getElement( 2, 2 ), loadedMatrix.getElement( 2, 2 ) );
+   EXPECT_EQ( savedMatrix.getElement( 2, 3 ), loadedMatrix.getElement( 2, 3 ) );
+
+   EXPECT_EQ( savedMatrix.getElement( 3, 0 ), loadedMatrix.getElement( 3, 0 ) );
+   EXPECT_EQ( savedMatrix.getElement( 3, 1 ), loadedMatrix.getElement( 3, 1 ) );
+   EXPECT_EQ( savedMatrix.getElement( 3, 2 ), loadedMatrix.getElement( 3, 2 ) );
+   EXPECT_EQ( savedMatrix.getElement( 3, 3 ), loadedMatrix.getElement( 3, 3 ) );
+
+   EXPECT_EQ( savedMatrix.getElement( 0, 0 ),  1 );
+   EXPECT_EQ( savedMatrix.getElement( 0, 1 ),  2 );
+   EXPECT_EQ( savedMatrix.getElement( 0, 2 ),  3 );
+   EXPECT_EQ( savedMatrix.getElement( 0, 3 ),  0 );
+
+   EXPECT_EQ( savedMatrix.getElement( 1, 0 ),  0 );
+   EXPECT_EQ( savedMatrix.getElement( 1, 1 ),  4 );
+   EXPECT_EQ( savedMatrix.getElement( 1, 2 ),  0 );
+   EXPECT_EQ( savedMatrix.getElement( 1, 3 ),  5 );
+
+   EXPECT_EQ( savedMatrix.getElement( 2, 0 ),  6 );
+   EXPECT_EQ( savedMatrix.getElement( 2, 1 ),  7 );
+   EXPECT_EQ( savedMatrix.getElement( 2, 2 ),  8 );
+   EXPECT_EQ( savedMatrix.getElement( 2, 3 ),  0 );
+
+   EXPECT_EQ( savedMatrix.getElement( 3, 0 ),  0 );
+   EXPECT_EQ( savedMatrix.getElement( 3, 1 ),  9 );
+   EXPECT_EQ( savedMatrix.getElement( 3, 2 ), 10 );
+   EXPECT_EQ( savedMatrix.getElement( 3, 3 ), 11 );
+
+   EXPECT_EQ( std::remove( filename ), 0 );
+}
+
+template< typename Matrix >
+void test_Print()
+{
+   using RealType = typename Matrix::RealType;
+   using DeviceType = typename Matrix::DeviceType;
+   using IndexType = typename Matrix::IndexType;
+
+   /*
+    * Sets up the following 5x4 sparse matrix:
+    *
+    *    /  1  2  3  0 \
+    *    |  0  0  0  4 |
+    *    |  5  6  7  0 |
+    *    |  0  8  9 10 |
+    *    \  0  0 11 12 /
+    */
+
+   const IndexType m_rows = 5;
+   const IndexType m_cols = 4;
+
+   Matrix m( m_rows, m_cols );
+   typename Matrix::CompressedRowLengthsVector rowLengths( m_rows );
+   rowLengths = 3;
+   m.setCompressedRowLengths( rowLengths );
+
+   RealType value = 1;
+   for( IndexType i = 0; i < m_cols - 1; i++ )   // 0th row
+      m.setElement( 0, i, value++ );
+
+   m.setElement( 1, 3, value++ );                // 1st row
+
+   for( IndexType i = 0; i < m_cols - 1; i++ )   // 2nd row
+      m.setElement( 2, i, value++ );
+
+   for( IndexType i = 1; i < m_cols; i++ )       // 3rd row
+      m.setElement( 3, i, value++ );
+
+   for( IndexType i = 2; i < m_cols; i++ )       // 4th row
+      m.setElement( 4, i, value++ );
+
+   std::stringstream printed;
+   std::stringstream couted;
+
+   //change the underlying buffer and save the old buffer
+   auto old_buf = std::cout.rdbuf(printed.rdbuf());
+
+   m.print( std::cout ); //all the std::cout goes to ss
+
+   std::cout.rdbuf(old_buf); //reset
+
+   couted << "Row: 0 ->  Col:0->1	 Col:1->2	 Col:2->3\t\n"
+             "Row: 1 ->  Col:3->4\t\n"
+             "Row: 2 ->  Col:0->5	 Col:1->6	 Col:2->7\t\n"
+             "Row: 3 ->  Col:1->8	 Col:2->9	 Col:3->10\t\n"
+             "Row: 4 ->  Col:2->11	 Col:3->12\t\n";
+
+   EXPECT_EQ( printed.str(), couted.str() );
+}
+
+#endif