HeterogeneousNonlinearConstraintTest Class Reference

Inheritance diagram for HeterogeneousNonlinearConstraintTest:

Public Member Functions
	LIBMESH_CPPUNIT_TEST_SUITE (HeterogeneousNonlinearConstraintTest)
	CPPUNIT_TEST (testNonzeroDirichletValues)
	CPPUNIT_TEST_SUITE_END ()

Private Member Functions
void	testNonzeroDirichletValues ()
	PetscNonlinearSolver enforces a constraint in each residual it hands PETSc.

Detailed Description

Definition at line 86 of file heterogeneous_nonlinear_constraint_test.C.

Member Function Documentation

CPPUNIT_TEST()

HeterogeneousNonlinearConstraintTest::CPPUNIT_TEST

(

testNonzeroDirichletValues

)

CPPUNIT_TEST_SUITE_END()

HeterogeneousNonlinearConstraintTest::CPPUNIT_TEST_SUITE_END

(

)

LIBMESH_CPPUNIT_TEST_SUITE()

HeterogeneousNonlinearConstraintTest::LIBMESH_CPPUNIT_TEST_SUITE

(

HeterogeneousNonlinearConstraintTest

)

testNonzeroDirichletValues()

void HeterogeneousNonlinearConstraintTest::testNonzeroDirichletValues ( )

inlineprivate

PetscNonlinearSolver enforces a constraint in each residual it hands PETSc.

With nonzero DirichletBoundary values on both ends, the exact solution of -u'' = 0 is the line between them, which a converged solve has to reproduce

Definition at line 104 of file heterogeneous_nonlinear_constraint_test.C.

  {
    LOG_UNIT_TEST;
 
    Mesh mesh(*TestCommWorld);
    MeshTools::Generation::build_line(mesh, 8, 0., 1., EDGE2);
 
    EquationSystems es(mesh);
    auto & sys = es.add_system<NonlinearImplicitSystem>("sys");
    const auto u = sys.add_variable("u", FIRST, LAGRANGE);
 
    // build_line's boundary ids
    const boundary_id_type left_id = 0, right_id = 1;
    const Real left_value = 2, right_value = 5;
    sys.get_dof_map().add_dirichlet_boundary(
        DirichletBoundary({left_id}, {u}, ConstFunction<Number>(left_value)));
    sys.get_dof_map().add_dirichlet_boundary(
        DirichletBoundary({right_id}, {u}, ConstFunction<Number>(right_value)));
 
    LaplaceResidualAndJacobian assembly;
    sys.nonlinear_solver->residual_and_jacobian_object = &assembly;
 
    es.init();
 
    // Start from an iterate that satisfies neither boundary value, so
    // the constrained rows have to pull it to them
    sys.solution->zero();
    sys.solution->close();
    sys.update();
 
    sys.solve();
 
    CPPUNIT_ASSERT(sys.nonlinear_solver->converged);
 
    for (const Node * node : mesh.local_node_ptr_range())
      {
        const Real x = (*node)(0);
        const Number exact = left_value + (right_value - left_value) * x;
        LIBMESH_ASSERT_NUMBERS_EQUAL(
            exact, (*sys.solution)(node->dof_number(sys.number(), u, 0)), TOLERANCE * TOLERANCE);
      }
  }

References libMesh::DofMap::add_dirichlet_boundary(), libMesh::EquationSystems::add_system(), libMesh::System::add_variable(), libMesh::MeshTools::Generation::build_line(), libMesh::EDGE2, libMesh::FIRST, libMesh::System::get_dof_map(), libMesh::EquationSystems::init(), libMesh::LAGRANGE, left_id, mesh, libMesh::NonlinearImplicitSystem::nonlinear_solver, libMesh::System::number(), libMesh::Real, right_id, libMesh::System::solution, libMesh::NonlinearImplicitSystem::solve(), TestCommWorld, libMesh::TOLERANCE, and libMesh::System::update().

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

• tests/systems/heterogeneous_nonlinear_constraint_test.C