libMesh::PatchRecoveryErrorEstimator Class Reference

#include <patch_recovery_error_estimator.h>

Inheritance diagram for libMesh::PatchRecoveryErrorEstimator:

[legend]

List of all members.

Classes
class	EstimateError
Public Types
typedef std::map< std::pair < const System *, unsigned int > , ErrorVector * >	ErrorMap
Public Member Functions
	PatchRecoveryErrorEstimator ()
	~PatchRecoveryErrorEstimator ()
virtual void	estimate_error (const System &system, ErrorVector &error_per_cell, const NumericVector< Number > *solution_vector=NULL, bool estimate_parent_error=false)
void	set_patch_reuse (bool)
virtual void	estimate_errors (const EquationSystems &equation_systems, ErrorVector &error_per_cell, const std::map< const System *, SystemNorm > &error_norms, const std::map< const System *, const NumericVector< Number > * > *solution_vectors=NULL, bool estimate_parent_error=false)
virtual void	estimate_errors (const EquationSystems &equation_systems, ErrorMap &errors_per_cell, const std::map< const System *, const NumericVector< Number > * > *solution_vectors=NULL, bool estimate_parent_error=false)
Public Attributes
unsigned int	target_patch_size
Patch::PMF	patch_growth_strategy
SystemNorm	error_norm
Protected Member Functions
void	reduce_error (std::vector< float > &error_per_cell) const
Static Protected Member Functions
static std::vector< Real >	specpoly (const unsigned int dim, const Order order, const Point p, const unsigned int matsize)
Protected Attributes
bool	patch_reuse
Friends
class	EstimateError

---

Detailed Description

This class implements the Patch Recovery error indicator.

Author:

Varis Carey, Benjamin S. Kirk, 2004.

Definition at line 47 of file patch_recovery_error_estimator.h.

---

Member Typedef Documentation

typedef std::map<std::pair<const System*, unsigned int>, ErrorVector*> libMesh::ErrorEstimator::ErrorMap [inherited]

When calculating many error vectors at once, we need a data structure to hold them all

Definition at line 107 of file error_estimator.h.

---

Constructor & Destructor Documentation

libMesh::PatchRecoveryErrorEstimator::PatchRecoveryErrorEstimator

(

)

[inline]

Constructor. Defaults to H1 seminorm. All Hilbert norms and seminorms should be supported now. W1,p and W2,p norms would be natural to support if any contributors make the effort.

Definition at line 56 of file patch_recovery_error_estimator.h.

References libMesh::ErrorEstimator::error_norm, and libMeshEnums::H1_SEMINORM.

                                :
    target_patch_size(20),
    patch_growth_strategy(&Patch::add_local_face_neighbors),
    patch_reuse(true)
      { error_norm = H1_SEMINORM; }

libMesh::PatchRecoveryErrorEstimator::~PatchRecoveryErrorEstimator

(

)

[inline]

Destructor.

Definition at line 65 of file patch_recovery_error_estimator.h.

{}

---

Member Function Documentation

void libMesh::PatchRecoveryErrorEstimator::estimate_error	(	const System &	system,
		ErrorVector &	error_per_cell,
		const NumericVector< Number > *	solution_vector = NULL,
		bool	estimate_parent_error = false
	)			[virtual]

This function uses the Patch Recovery error estimate to estimate the error on each cell. The estimated error is output in the vector error_per_cell

Implements libMesh::ErrorEstimator.

Reimplemented in libMesh::WeightedPatchRecoveryErrorEstimator.

Definition at line 129 of file patch_recovery_error_estimator.C.

References libMesh::MeshBase::active_local_elements_begin(), libMesh::MeshBase::active_local_elements_end(), EstimateError, libMesh::AutoPtr< Tp >::get(), libMesh::System::get_mesh(), libMesh::MeshBase::max_elem_id(), mesh, libMesh::Threads::parallel_for(), libMesh::ErrorEstimator::reduce_error(), libMesh::System::solution, and libMesh::NumericVector< T >::swap().

{
  START_LOG("estimate_error()", "PatchRecoveryErrorEstimator");

  // The current mesh
  const MeshBase& mesh = system.get_mesh();

  // Resize the error_per_cell vector to be
  // the number of elements, initialize it to 0.
  error_per_cell.resize (mesh.max_elem_id());
  std::fill (error_per_cell.begin(), error_per_cell.end(), 0.);

  // Prepare current_local_solution to localize a non-standard
  // solution vector if necessary
  if (solution_vector && solution_vector != system.solution.get())
    {
      NumericVector<Number>* newsol =
        const_cast<NumericVector<Number>*>(solution_vector);
      System &sys = const_cast<System&>(system);
      newsol->swap(*sys.solution);
      sys.update();
    }

  //------------------------------------------------------------
  // Iterate over all the active elements in the mesh
  // that live on this processor.
  Threads::parallel_for (ConstElemRange(mesh.active_local_elements_begin(),
                                        mesh.active_local_elements_end(),
                                        200),
                         EstimateError(system,
                                       *this,
                                       error_per_cell)
                         );

  // Each processor has now computed the error contributions
  // for its local elements, and error_per_cell contains 0 for all the
  // non-local elements.  Summing the vector will provide the true
  // value for each element, local or remote
  this->reduce_error(error_per_cell);

  // If we used a non-standard solution before, now is the time to fix
  // the current_local_solution
  if (solution_vector && solution_vector != system.solution.get())
    {
      NumericVector<Number>* newsol =
        const_cast<NumericVector<Number>*>(solution_vector);
      System &sys = const_cast<System&>(system);
      newsol->swap(*sys.solution);
      sys.update();
    }

  STOP_LOG("estimate_error()", "PatchRecoveryErrorEstimator");
}

void libMesh::ErrorEstimator::estimate_errors	(	const EquationSystems &	equation_systems,
		ErrorMap &	errors_per_cell,
		const std::map< const System *, const NumericVector< Number > * > *	solution_vectors = NULL,
		bool	estimate_parent_error = false
	)			[virtual, inherited]

This virtual function can be redefined in derived classes, but by default it calls estimate_error repeatedly to calculate the requested error vectors.

Currently this function ignores the error_norm.weight() values because it calculates each variable's error individually, unscaled.

The user selects which errors get computed by filling a map with error vectors: If errors_per_cell[&system][v] exists, it will be filled with the error values in variable v of system

FIXME: This is a default implementation - derived classes should reimplement it for efficiency.

Reimplemented in libMesh::UniformRefinementEstimator.

Definition at line 93 of file error_estimator.C.

References libMesh::ErrorEstimator::error_norm, libMesh::ErrorEstimator::estimate_error(), libMesh::EquationSystems::get_system(), libMesh::EquationSystems::n_systems(), libMesh::System::n_vars(), n_vars, and libMesh::SystemNorm::type().

{
  SystemNorm old_error_norm = this->error_norm;

  // Find the requested error values from each system
  for (unsigned int s = 0; s != equation_systems.n_systems(); ++s)
    {
      const System &sys = equation_systems.get_system(s);

      unsigned int n_vars = sys.n_vars();

      for (unsigned int v = 0; v != n_vars; ++v)
        {
          // Only fill in ErrorVectors the user asks for
          if (errors_per_cell.find(std::make_pair(&sys, v)) ==
              errors_per_cell.end())
            continue;

          // Calculate error in only one variable
          std::vector<Real> weights(n_vars, 0.0);
          weights[v] = 1.0;
          this->error_norm =
            SystemNorm(std::vector<FEMNormType>(n_vars, old_error_norm.type(v)),
                       weights);

          const NumericVector<Number>* solution_vector = NULL;
          if (solution_vectors &&
              solution_vectors->find(&sys) != solution_vectors->end())
            solution_vector = solution_vectors->find(&sys)->second;

          this->estimate_error
            (sys, *errors_per_cell[std::make_pair(&sys, v)],
             solution_vector, estimate_parent_error);
        }
    }

  // Restore our old state before returning
  this->error_norm = old_error_norm;
}

void libMesh::ErrorEstimator::estimate_errors	(	const EquationSystems &	equation_systems,
		ErrorVector &	error_per_cell,
		const std::map< const System *, SystemNorm > &	error_norms,
		const std::map< const System *, const NumericVector< Number > * > *	solution_vectors = NULL,
		bool	estimate_parent_error = false
	)			[virtual, inherited]

This virtual function can be redefined in derived classes, but by default computes the sum of the error_per_cell for each system in the equation_systems.

Currently this function ignores the error_norm member variable, and uses the function argument error_norms instead.

This function is named estimate_errors instead of estimate_error because otherwise C++ can get confused.

Reimplemented in libMesh::UniformRefinementEstimator.

Definition at line 47 of file error_estimator.C.

References libMesh::ErrorEstimator::error_norm, libMesh::ErrorEstimator::estimate_error(), libMesh::EquationSystems::get_system(), and libMesh::EquationSystems::n_systems().

{
  SystemNorm old_error_norm = this->error_norm;

  // Sum the error values from each system
  for (unsigned int s = 0; s != equation_systems.n_systems(); ++s)
    {
      ErrorVector system_error_per_cell;
      const System &sys = equation_systems.get_system(s);
      if (error_norms.find(&sys) == error_norms.end())
        this->error_norm = old_error_norm;
      else
        this->error_norm = error_norms.find(&sys)->second;

      const NumericVector<Number>* solution_vector = NULL;
      if (solution_vectors &&
          solution_vectors->find(&sys) != solution_vectors->end())
        solution_vector = solution_vectors->find(&sys)->second;

      this->estimate_error(sys, system_error_per_cell,
                           solution_vector, estimate_parent_error);

      if (s)
        {
          libmesh_assert_equal_to (error_per_cell.size(), system_error_per_cell.size());
          for (unsigned int i=0; i != error_per_cell.size(); ++i)
            error_per_cell[i] += system_error_per_cell[i];
        }
      else
        error_per_cell = system_error_per_cell;
    }

  // Restore our old state before returning
  this->error_norm = old_error_norm;
}

void libMesh::ErrorEstimator::reduce_error

(

std::vector< float > &

error_per_cell

)

const [protected, inherited]

This method takes the local error contributions in error_per_cell from each processor and combines them to get the global error vector.

Referenced by libMesh::WeightedPatchRecoveryErrorEstimator::estimate_error(), estimate_error(), and libMesh::JumpErrorEstimator::estimate_error().

void libMesh::PatchRecoveryErrorEstimator::set_patch_reuse

(

bool

patch_reuse_flag

)

Definition at line 47 of file patch_recovery_error_estimator.C.

References patch_reuse.

  {
    patch_reuse = patch_reuse_flag;
  }

std::vector< Real > libMesh::PatchRecoveryErrorEstimator::specpoly	(	const unsigned int	dim,
		const Order	order,
		const Point	p,
		const unsigned int	matsize
	)			[static, protected]

Returns the spectral polynomial basis function values at a point x,y,z

Definition at line 54 of file patch_recovery_error_estimator.C.

References libMesh::Real.

Referenced by libMesh::WeightedPatchRecoveryErrorEstimator::EstimateError::operator()(), and libMesh::PatchRecoveryErrorEstimator::EstimateError::operator()().

{
  std::vector<Real> psi;
  psi.reserve(matsize);
  Real x = p(0), y=0., z=0.;
  unsigned int npows = order+1;
  std::vector<Real> xpow(npows,1.), ypow, zpow;
  for (unsigned int i=1; i != npows; ++i)
    xpow[i] = xpow[i-1] * x;
  if (dim > 1)
    {
      y = p(1);
      ypow.resize(npows,1.);
      for (unsigned int i=1; i != npows; ++i)
        ypow[i] = ypow[i-1] * y;
    }
  if (dim > 2)
    {
      z = p(2);
      zpow.resize(npows,1.);
      for (unsigned int i=1; i != npows; ++i)
        zpow[i] = zpow[i-1] * z;
    }

  // builds psi vector of form 1 x y z x^2 xy xz y^2 yz z^2 etc..
  // I haven't added 1D support here
  for (unsigned int poly_deg=0; poly_deg <= static_cast<unsigned int>(order) ; poly_deg++)
    { // loop over all polynomials of total degreee = poly_deg

      switch (dim)
        {
          // 3D spectral polynomial basis functions
        case 3:
          {
            for (int xexp=poly_deg; xexp >= 0; xexp--) // use an int for xexp since we -- it
              for (int yexp=poly_deg-xexp; yexp >= 0; yexp--)
                {
                  int zexp = poly_deg - xexp - yexp;
                  psi.push_back(xpow[xexp]*ypow[yexp]*zpow[zexp]);
                }
            break;
          }

          // 2D spectral polynomial basis functions
        case 2:
          {
            for (int xexp=poly_deg; xexp >= 0; xexp--) // use an int for xexp since we -- it
              {
                int yexp = poly_deg - xexp;
                psi.push_back(xpow[xexp]*ypow[yexp]);
              }
            break;
          }

          // 1D spectral polynomial basis functions
        case 1:
          {
            int xexp = poly_deg;
            psi.push_back(xpow[xexp]);
            break;
          }

        default:
          libmesh_error();
        }
    }

  return psi;
}

---

Friends And Related Function Documentation

friend class EstimateError [friend]

Reimplemented in libMesh::WeightedPatchRecoveryErrorEstimator.

Definition at line 139 of file patch_recovery_error_estimator.h.

Referenced by estimate_error().

---

Member Data Documentation

SystemNorm libMesh::ErrorEstimator::error_norm [inherited]

When estimating the error in a single system, the error_norm is used to control the scaling and norm choice for each variable. Not all estimators will support all norm choices. The default scaling is for all variables to be weighted equally. The default norm choice depends on the error estimator.

Part of this functionality was supported via component_scale and sobolev_order in older libMesh versions, and a small part was supported via component_mask in even older versions. Hopefully the encapsulation here will allow us to avoid changing this API again.

Definition at line 139 of file error_estimator.h.

Referenced by libMesh::AdjointRefinementEstimator::AdjointRefinementEstimator(), libMesh::KellyErrorEstimator::boundary_side_integration(), libMesh::DiscontinuityMeasure::boundary_side_integration(), libMesh::DiscontinuityMeasure::DiscontinuityMeasure(), libMesh::JumpErrorEstimator::estimate_error(), libMesh::AdjointResidualErrorEstimator::estimate_error(), libMesh::ErrorEstimator::estimate_errors(), libMesh::ExactErrorEstimator::ExactErrorEstimator(), libMesh::ExactErrorEstimator::find_squared_element_error(), libMesh::KellyErrorEstimator::internal_side_integration(), libMesh::LaplacianErrorEstimator::internal_side_integration(), libMesh::DiscontinuityMeasure::internal_side_integration(), libMesh::KellyErrorEstimator::KellyErrorEstimator(), libMesh::LaplacianErrorEstimator::LaplacianErrorEstimator(), libMesh::WeightedPatchRecoveryErrorEstimator::EstimateError::operator()(), libMesh::PatchRecoveryErrorEstimator::EstimateError::operator()(), PatchRecoveryErrorEstimator(), and libMesh::UniformRefinementEstimator::UniformRefinementEstimator().

Patch::PMF libMesh::PatchRecoveryErrorEstimator::patch_growth_strategy

The PatchErrorEstimator will use this pointer to a Patch member function when growing patches. The default strategy used is Patch::add_local_face_neighbors. Patch::add_local_point_neighbors may be more reliable but slower.

Definition at line 91 of file patch_recovery_error_estimator.h.

Referenced by libMesh::WeightedPatchRecoveryErrorEstimator::EstimateError::operator()(), and libMesh::PatchRecoveryErrorEstimator::EstimateError::operator()().

bool libMesh::PatchRecoveryErrorEstimator::patch_reuse [protected]

Definition at line 106 of file patch_recovery_error_estimator.h.

Referenced by libMesh::WeightedPatchRecoveryErrorEstimator::EstimateError::operator()(), libMesh::PatchRecoveryErrorEstimator::EstimateError::operator()(), and set_patch_reuse().

unsigned int libMesh::PatchRecoveryErrorEstimator::target_patch_size

The PatchErrorEstimator will build patches of at least this many elements to perform estimates

Definition at line 83 of file patch_recovery_error_estimator.h.

Referenced by libMesh::WeightedPatchRecoveryErrorEstimator::EstimateError::operator()(), and libMesh::PatchRecoveryErrorEstimator::EstimateError::operator()().

---

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

• patch_recovery_error_estimator.h
• patch_recovery_error_estimator.C