void TestChebyshevVsCG() throw (Exception)
{
unsigned num_nodes = 1331;
DistributedVectorFactory factory(num_nodes);
Vec parallel_layout = factory.CreateVec(2);
unsigned cg_its;
unsigned chebyshev_its;
Timer::Reset();
{
Mat system_matrix;
// Note that this test deadlocks if the file's not on the disk
PetscTools::ReadPetscObject(system_matrix, "linalg/test/data/matrices/cube_6000elems_half_activated.mat", parallel_layout);
Vec system_rhs;
// Note that this test deadlocks if the file's not on the disk
PetscTools::ReadPetscObject(system_rhs, "linalg/test/data/matrices/cube_6000elems_half_activated.vec", parallel_layout);
LinearSystem ls = LinearSystem(system_rhs, system_matrix);
ls.SetMatrixIsSymmetric();
ls.SetAbsoluteTolerance(1e-9);
ls.SetKspType("cg");
ls.SetPcType("bjacobi");
Vec solution = ls.Solve();
cg_its = ls.GetNumIterations();
PetscTools::Destroy(system_matrix);
PetscTools::Destroy(system_rhs);
PetscTools::Destroy(solution);
}
Timer::PrintAndReset("CG");
{
Mat system_matrix;
// Note that this test deadlocks if the file's not on the disk
PetscTools::ReadPetscObject(system_matrix, "linalg/test/data/matrices/cube_6000elems_half_activated.mat", parallel_layout);
Vec system_rhs;
// Note that this test deadlocks if the file's not on the disk
PetscTools::ReadPetscObject(system_rhs, "linalg/test/data/matrices/cube_6000elems_half_activated.vec", parallel_layout);
LinearSystem ls = LinearSystem(system_rhs, system_matrix);
ls.SetMatrixIsSymmetric();
ls.SetAbsoluteTolerance(1e-9);
ls.SetKspType("chebychev");
ls.SetPcType("bjacobi");
Vec solution = ls.Solve();
chebyshev_its = ls.GetNumIterations();
PetscTools::Destroy(system_matrix);
PetscTools::Destroy(system_rhs);
PetscTools::Destroy(solution);
}
Timer::Print("Chebyshev");
TS_ASSERT_LESS_THAN(cg_its, 15u); // Takes 14 iterations with 16 cores
TS_ASSERT_LESS_THAN(chebyshev_its, 17u); // Takes 16 iterations with 16 cores
PetscTools::Destroy(parallel_layout);
}
void TestChebyshevAdaptiveVsNoAdaptive() throw (Exception)
{
unsigned num_nodes = 1331;
DistributedVectorFactory factory(num_nodes);
Vec parallel_layout = factory.CreateVec(2);
// Solving with zero guess for coverage
Vec zero_guess = factory.CreateVec(2);
double zero = 0.0;
#if (PETSC_VERSION_MAJOR == 2 && PETSC_VERSION_MINOR == 2)
VecSet(&zero, zero_guess);
#else
VecSet(zero_guess, zero);
#endif
Mat system_matrix;
// Note that this test deadlocks if the file's not on the disk
PetscTools::ReadPetscObject(system_matrix, "linalg/test/data/matrices/cube_6000elems_half_activated.mat", parallel_layout);
Vec system_rhs;
// Note that this test deadlocks if the file's not on the disk
PetscTools::ReadPetscObject(system_rhs, "linalg/test/data/matrices/cube_6000elems_half_activated.vec", parallel_layout);
// Make sure we are not inheriting a non-default number of iterations from previous test
std::stringstream num_it_str;
num_it_str << 1000;
PetscOptionsSetValue("-ksp_max_it", num_it_str.str().c_str());
try
{
LinearSystem ls = LinearSystem(system_rhs, system_matrix);
ls.SetMatrixIsSymmetric();
// Solve to relative convergence for coverage
ls.SetRelativeTolerance(1e-6);
ls.SetPcType("jacobi");
ls.SetKspType("chebychev");
ls.SetUseFixedNumberIterations(true, 64);
// Solving with zero guess for coverage.
Vec solution = ls.Solve(zero_guess);
unsigned chebyshev_adaptive_its = ls.GetNumIterations();
TS_ASSERT_EQUALS(chebyshev_adaptive_its, 40u);
TS_ASSERT_DELTA(ls.mEigMin, 0.0124, 1e-4);
TS_ASSERT_DELTA(ls.mEigMax, 1.8810, 1e-4);
PetscTools::Destroy(solution);
}
catch (Exception& e)
{
if (e.GetShortMessage() == "Chebyshev with fixed number of iterations is known to be broken in PETSc <= 2.3.2")
{
WARNING(e.GetShortMessage());
}
else
{
TS_FAIL(e.GetShortMessage());
}
}
// Make sure we are not inheriting a non-default number of iterations from previous test
PetscOptionsSetValue("-ksp_max_it", num_it_str.str().c_str());
{
LinearSystem ls = LinearSystem(system_rhs, system_matrix);
ls.SetMatrixIsSymmetric();
ls.SetRelativeTolerance(1e-6);
ls.SetPcType("jacobi");
ls.SetKspType("chebychev");
Vec solution = ls.Solve(zero_guess);
unsigned chebyshev_no_adaptive_its = ls.GetNumIterations();
TS_ASSERT_LESS_THAN(chebyshev_no_adaptive_its, 100u); // Normally 88, but 99 on maverick & natty
TS_ASSERT_DELTA(ls.mEigMin, 0.0124, 1e-4);
TS_ASSERT_DELTA(ls.mEigMax, 1.8841, 1e-4);
PetscTools::Destroy(solution);
}
// Make sure we are not inheriting a non-default number of iterations from previous test
PetscOptionsSetValue("-ksp_max_it", num_it_str.str().c_str());
{
LinearSystem ls = LinearSystem(system_rhs, system_matrix);
ls.SetMatrixIsSymmetric();
ls.SetRelativeTolerance(1e-6);
ls.SetPcType("jacobi");
ls.SetKspType("cg");
Vec solution = ls.Solve(zero_guess);
unsigned cg_its = ls.GetNumIterations();
TS_ASSERT_EQUALS(cg_its, 40u);
TS_ASSERT_EQUALS(ls.mEigMin, DBL_MAX);
TS_ASSERT_EQUALS(ls.mEigMax, DBL_MIN);
PetscTools::Destroy(solution);
}
PetscTools::Destroy(system_matrix);
PetscTools::Destroy(system_rhs);
PetscTools::Destroy(parallel_layout);
PetscTools::Destroy(zero_guess);
}