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vector_tools_integrate_difference.templates.h
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vector_tools_integrate_difference.templates.h
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// ---------------------------------------------------------------------
//
// Copyright (C) 1998 - 2021 by the deal.II authors
//
// This file is part of the deal.II library.
//
// The deal.II library is free software; you can use it, redistribute
// it, and/or modify it under the terms of the GNU Lesser General
// Public License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
// The full text of the license can be found in the file LICENSE.md at
// the top level directory of deal.II.
//
// ---------------------------------------------------------------------
#ifndef dealii_vector_tools_integrate_difference_templates_h
#define dealii_vector_tools_integrate_difference_templates_h
#include <deal.II/hp/fe_values.h>
#include <deal.II/lac/block_vector.h>
#include <deal.II/lac/la_parallel_block_vector.h>
#include <deal.II/lac/la_parallel_vector.h>
#include <deal.II/lac/la_vector.h>
#include <deal.II/lac/petsc_block_vector.h>
#include <deal.II/lac/petsc_vector.h>
#include <deal.II/lac/trilinos_parallel_block_vector.h>
#include <deal.II/lac/trilinos_vector.h>
#include <deal.II/numerics/vector_tools_integrate_difference.h>
DEAL_II_NAMESPACE_OPEN
namespace VectorTools
{
namespace internal
{
template <int dim, int spacedim, typename Number>
struct IDScratchData
{
IDScratchData(const dealii::hp::MappingCollection<dim, spacedim> &mapping,
const dealii::hp::FECollection<dim, spacedim> & fe,
const dealii::hp::QCollection<dim> & q,
const UpdateFlags update_flags);
IDScratchData(const IDScratchData &data);
void
resize_vectors(const unsigned int n_q_points,
const unsigned int n_components);
std::vector<Vector<Number>> function_values;
std::vector<std::vector<Tensor<1, spacedim, Number>>> function_grads;
std::vector<double> weight_values;
std::vector<Vector<double>> weight_vectors;
std::vector<Vector<Number>> psi_values;
std::vector<std::vector<Tensor<1, spacedim, Number>>> psi_grads;
std::vector<Number> psi_scalar;
std::vector<Number> tmp_values;
std::vector<Vector<Number>> tmp_vector_values;
std::vector<Tensor<1, spacedim, Number>> tmp_gradients;
std::vector<std::vector<Tensor<1, spacedim, Number>>>
tmp_vector_gradients;
dealii::hp::FEValues<dim, spacedim> x_fe_values;
};
template <int dim, int spacedim, typename Number>
IDScratchData<dim, spacedim, Number>::IDScratchData(
const dealii::hp::MappingCollection<dim, spacedim> &mapping,
const dealii::hp::FECollection<dim, spacedim> & fe,
const dealii::hp::QCollection<dim> & q,
const UpdateFlags update_flags)
: x_fe_values(mapping, fe, q, update_flags)
{}
template <int dim, int spacedim, typename Number>
IDScratchData<dim, spacedim, Number>::IDScratchData(
const IDScratchData &data)
: x_fe_values(data.x_fe_values.get_mapping_collection(),
data.x_fe_values.get_fe_collection(),
data.x_fe_values.get_quadrature_collection(),
data.x_fe_values.get_update_flags())
{}
template <int dim, int spacedim, typename Number>
void
IDScratchData<dim, spacedim, Number>::resize_vectors(
const unsigned int n_q_points,
const unsigned int n_components)
{
function_values.resize(n_q_points, Vector<Number>(n_components));
function_grads.resize(
n_q_points, std::vector<Tensor<1, spacedim, Number>>(n_components));
weight_values.resize(n_q_points);
weight_vectors.resize(n_q_points, Vector<double>(n_components));
psi_values.resize(n_q_points, Vector<Number>(n_components));
psi_grads.resize(n_q_points,
std::vector<Tensor<1, spacedim, Number>>(n_components));
psi_scalar.resize(n_q_points);
tmp_values.resize(n_q_points);
tmp_vector_values.resize(n_q_points, Vector<Number>(n_components));
tmp_gradients.resize(n_q_points);
tmp_vector_gradients.resize(
n_q_points, std::vector<Tensor<1, spacedim, Number>>(n_components));
}
namespace internal
{
template <typename number>
double
mean_to_double(const number &mean_value)
{
return mean_value;
}
template <typename number>
double
mean_to_double(const std::complex<number> &mean_value)
{
// we need to return double as a norm, but mean value is a complex
// number. Panic and return real-part while warning the user that
// they shall never do that.
Assert(
false,
ExcMessage(
"Mean value norm is not implemented for complex-valued vectors"));
return mean_value.real();
}
} // namespace internal
// avoid compiling inner function for many vector types when we always
// really do the same thing by putting the main work into this helper
// function
template <int dim, int spacedim, typename Number>
double
integrate_difference_inner(const Function<spacedim, Number> &exact_solution,
const NormType & norm,
const Function<spacedim> * weight,
const UpdateFlags update_flags,
const double exponent,
const unsigned int n_components,
IDScratchData<dim, spacedim, Number> &data)
{
const bool fe_is_system = (n_components != 1);
const dealii::FEValues<dim, spacedim> &fe_values =
data.x_fe_values.get_present_fe_values();
const unsigned int n_q_points = fe_values.n_quadrature_points;
if (weight != nullptr)
{
if (weight->n_components > 1)
weight->vector_value_list(fe_values.get_quadrature_points(),
data.weight_vectors);
else
{
weight->value_list(fe_values.get_quadrature_points(),
data.weight_values);
for (unsigned int k = 0; k < n_q_points; ++k)
data.weight_vectors[k] = data.weight_values[k];
}
}
else
{
for (unsigned int k = 0; k < n_q_points; ++k)
data.weight_vectors[k] = 1.;
}
if (update_flags & update_values)
{
// first compute the exact solution (vectors) at the quadrature
// points. try to do this as efficient as possible by avoiding a
// second virtual function call in case the function really has only
// one component
//
// TODO: we have to work a bit here because the Function<dim,double>
// interface of the argument denoting the exact function only
// provides us with double/Tensor<1,dim> values, rather than
// with the correct data type. so evaluate into a temp
// object, then copy around
if (fe_is_system)
{
exact_solution.vector_value_list(
fe_values.get_quadrature_points(), data.tmp_vector_values);
for (unsigned int i = 0; i < n_q_points; ++i)
data.psi_values[i] = data.tmp_vector_values[i];
}
else
{
exact_solution.value_list(fe_values.get_quadrature_points(),
data.tmp_values);
for (unsigned int i = 0; i < n_q_points; ++i)
data.psi_values[i](0) = data.tmp_values[i];
}
// then subtract finite element fe_function
for (unsigned int q = 0; q < n_q_points; ++q)
for (unsigned int i = 0; i < data.psi_values[q].size(); ++i)
data.psi_values[q][i] -= data.function_values[q][i];
}
// Do the same for gradients, if required
if (update_flags & update_gradients)
{
// try to be a little clever to avoid recursive virtual function
// calls when calling gradient_list for functions that are really
// scalar functions
if (fe_is_system)
{
exact_solution.vector_gradient_list(
fe_values.get_quadrature_points(), data.tmp_vector_gradients);
for (unsigned int i = 0; i < n_q_points; ++i)
for (unsigned int comp = 0; comp < data.psi_grads[i].size();
++comp)
data.psi_grads[i][comp] = data.tmp_vector_gradients[i][comp];
}
else
{
exact_solution.gradient_list(fe_values.get_quadrature_points(),
data.tmp_gradients);
for (unsigned int i = 0; i < n_q_points; ++i)
data.psi_grads[i][0] = data.tmp_gradients[i];
}
// then subtract finite element function_grads. We need to be
// careful in the codimension one case, since there we only have
// tangential gradients in the finite element function, not the full
// gradient. This is taken care of, by subtracting the normal
// component of the gradient from the exact function.
if (update_flags & update_normal_vectors)
for (unsigned int k = 0; k < n_components; ++k)
for (unsigned int q = 0; q < n_q_points; ++q)
{
// compute (f.n) n
const typename ProductType<Number, double>::type f_dot_n =
data.psi_grads[q][k] * fe_values.normal_vector(q);
const Tensor<1, spacedim, Number> f_dot_n_times_n =
f_dot_n * fe_values.normal_vector(q);
data.psi_grads[q][k] -=
(data.function_grads[q][k] + f_dot_n_times_n);
}
else
for (unsigned int k = 0; k < n_components; ++k)
for (unsigned int q = 0; q < n_q_points; ++q)
for (unsigned int d = 0; d < spacedim; ++d)
data.psi_grads[q][k][d] -= data.function_grads[q][k][d];
}
double diff = 0;
Number diff_mean = 0;
// First work on function values:
switch (norm)
{
case mean:
// Compute values in quadrature points and integrate
for (unsigned int q = 0; q < n_q_points; ++q)
{
Number sum = 0;
for (unsigned int k = 0; k < n_components; ++k)
if (data.weight_vectors[q](k) != 0)
sum += data.psi_values[q](k) * data.weight_vectors[q](k);
diff_mean += sum * fe_values.JxW(q);
}
break;
case Lp_norm:
case L1_norm:
case W1p_norm:
// Compute values in quadrature points and integrate
for (unsigned int q = 0; q < n_q_points; ++q)
{
double sum = 0;
for (unsigned int k = 0; k < n_components; ++k)
if (data.weight_vectors[q](k) != 0)
sum += std::pow(static_cast<double>(
numbers::NumberTraits<Number>::abs_square(
data.psi_values[q](k))),
exponent / 2.) *
data.weight_vectors[q](k);
diff += sum * fe_values.JxW(q);
}
// Compute the root only if no derivative values are added later
if (!(update_flags & update_gradients))
diff = std::pow(diff, 1. / exponent);
break;
case L2_norm:
case H1_norm:
// Compute values in quadrature points and integrate
for (unsigned int q = 0; q < n_q_points; ++q)
{
double sum = 0;
for (unsigned int k = 0; k < n_components; ++k)
if (data.weight_vectors[q](k) != 0)
sum += numbers::NumberTraits<Number>::abs_square(
data.psi_values[q](k)) *
data.weight_vectors[q](k);
diff += sum * fe_values.JxW(q);
}
// Compute the root only, if no derivative values are added later
if (norm == L2_norm)
diff = std::sqrt(diff);
break;
case Linfty_norm:
case W1infty_norm:
for (unsigned int q = 0; q < n_q_points; ++q)
for (unsigned int k = 0; k < n_components; ++k)
if (data.weight_vectors[q](k) != 0)
diff = std::max(diff,
double(std::abs(data.psi_values[q](k) *
data.weight_vectors[q](k))));
break;
case H1_seminorm:
case Hdiv_seminorm:
case W1p_seminorm:
case W1infty_seminorm:
// function values are not used for these norms
break;
default:
Assert(false, ExcNotImplemented());
break;
}
// Now compute terms depending on derivatives:
switch (norm)
{
case W1p_seminorm:
case W1p_norm:
for (unsigned int q = 0; q < n_q_points; ++q)
{
double sum = 0;
for (unsigned int k = 0; k < n_components; ++k)
if (data.weight_vectors[q](k) != 0)
sum += std::pow(data.psi_grads[q][k].norm_square(),
exponent / 2.) *
data.weight_vectors[q](k);
diff += sum * fe_values.JxW(q);
}
diff = std::pow(diff, 1. / exponent);
break;
case H1_seminorm:
case H1_norm:
for (unsigned int q = 0; q < n_q_points; ++q)
{
double sum = 0;
for (unsigned int k = 0; k < n_components; ++k)
if (data.weight_vectors[q](k) != 0)
sum += data.psi_grads[q][k].norm_square() *
data.weight_vectors[q](k);
diff += sum * fe_values.JxW(q);
}
diff = std::sqrt(diff);
break;
case Hdiv_seminorm:
for (unsigned int q = 0; q < n_q_points; ++q)
{
unsigned int idx = 0;
if (weight != nullptr)
for (; idx < n_components; ++idx)
if (data.weight_vectors[0](idx) > 0)
break;
Assert(
n_components >= idx + dim,
ExcMessage(
"You can only ask for the Hdiv norm for a finite element "
"with at least 'dim' components. In that case, this function "
"will find the index of the first non-zero weight and take "
"the divergence of the 'dim' components that follow it."));
Number sum = 0;
// take the trace of the derivatives scaled by the weight and
// square it
for (unsigned int k = idx; k < idx + dim; ++k)
if (data.weight_vectors[q](k) != 0)
sum += data.psi_grads[q][k][k - idx] *
std::sqrt(data.weight_vectors[q](k));
diff += numbers::NumberTraits<Number>::abs_square(sum) *
fe_values.JxW(q);
}
diff = std::sqrt(diff);
break;
case W1infty_seminorm:
case W1infty_norm:
{
double t = 0;
for (unsigned int q = 0; q < n_q_points; ++q)
for (unsigned int k = 0; k < n_components; ++k)
if (data.weight_vectors[q](k) != 0)
for (unsigned int d = 0; d < dim; ++d)
t = std::max(t,
double(std::abs(data.psi_grads[q][k][d]) *
data.weight_vectors[q](k)));
// then add seminorm to norm if that had previously been
// computed
diff += t;
}
break;
default:
break;
}
if (norm == mean)
diff = internal::mean_to_double(diff_mean);
// append result of this cell to the end of the vector
AssertIsFinite(diff);
return diff;
}
template <int dim, int spacedim, class InVector, class OutVector>
static void
do_integrate_difference(
const dealii::hp::MappingCollection<dim, spacedim> & mapping,
const DoFHandler<dim, spacedim> & dof,
const InVector & fe_function,
const Function<spacedim, typename InVector::value_type> &exact_solution,
OutVector & difference,
const dealii::hp::QCollection<dim> & q,
const NormType & norm,
const Function<spacedim> * weight,
const double exponent_1)
{
using Number = typename InVector::value_type;
// we mark the "exponent" parameter to this function "const" since it is
// strictly incoming, but we need to set it to something different later
// on, if necessary, so have a read-write version of it:
double exponent = exponent_1;
const unsigned int n_components = dof.get_fe(0).n_components();
Assert(exact_solution.n_components == n_components,
ExcDimensionMismatch(exact_solution.n_components, n_components));
if (weight != nullptr)
{
Assert((weight->n_components == 1) ||
(weight->n_components == n_components),
ExcDimensionMismatch(weight->n_components, n_components));
}
difference.reinit(dof.get_triangulation().n_active_cells());
switch (norm)
{
case L2_norm:
case H1_seminorm:
case H1_norm:
case Hdiv_seminorm:
exponent = 2.;
break;
case L1_norm:
exponent = 1.;
break;
default:
break;
}
UpdateFlags update_flags =
UpdateFlags(update_quadrature_points | update_JxW_values);
switch (norm)
{
case H1_seminorm:
case Hdiv_seminorm:
case W1p_seminorm:
case W1infty_seminorm:
update_flags |= UpdateFlags(update_gradients);
if (spacedim == dim + 1)
update_flags |= UpdateFlags(update_normal_vectors);
break;
case H1_norm:
case W1p_norm:
case W1infty_norm:
update_flags |= UpdateFlags(update_gradients);
if (spacedim == dim + 1)
update_flags |= UpdateFlags(update_normal_vectors);
DEAL_II_FALLTHROUGH;
default:
update_flags |= UpdateFlags(update_values);
break;
}
const dealii::hp::FECollection<dim, spacedim> &fe_collection =
dof.get_fe_collection();
IDScratchData<dim, spacedim, Number> data(mapping,
fe_collection,
q,
update_flags);
// loop over all cells
for (const auto &cell : dof.active_cell_iterators())
if (cell->is_locally_owned())
{
// initialize for this cell
data.x_fe_values.reinit(cell);
const dealii::FEValues<dim, spacedim> &fe_values =
data.x_fe_values.get_present_fe_values();
const unsigned int n_q_points = fe_values.n_quadrature_points;
data.resize_vectors(n_q_points, n_components);
if (update_flags & update_values)
fe_values.get_function_values(fe_function, data.function_values);
if (update_flags & update_gradients)
fe_values.get_function_gradients(fe_function,
data.function_grads);
difference(cell->active_cell_index()) =
integrate_difference_inner<dim, spacedim, Number>(exact_solution,
norm,
weight,
update_flags,
exponent,
n_components,
data);
}
else
// the cell is a ghost cell or is artificial. write a zero into the
// corresponding value of the returned vector
difference(cell->active_cell_index()) = 0;
}
} // namespace internal
template <int dim, class InVector, class OutVector, int spacedim>
void
integrate_difference(
const Mapping<dim, spacedim> & mapping,
const DoFHandler<dim, spacedim> & dof,
const InVector & fe_function,
const Function<spacedim, typename InVector::value_type> &exact_solution,
OutVector & difference,
const Quadrature<dim> & q,
const NormType & norm,
const Function<spacedim> * weight,
const double exponent)
{
internal::do_integrate_difference(hp::MappingCollection<dim, spacedim>(
mapping),
dof,
fe_function,
exact_solution,
difference,
hp::QCollection<dim>(q),
norm,
weight,
exponent);
}
template <int dim, class InVector, class OutVector, int spacedim>
void
integrate_difference(
const DoFHandler<dim, spacedim> & dof,
const InVector & fe_function,
const Function<spacedim, typename InVector::value_type> &exact_solution,
OutVector & difference,
const Quadrature<dim> & q,
const NormType & norm,
const Function<spacedim> * weight,
const double exponent)
{
internal::do_integrate_difference(
hp::StaticMappingQ1<dim, spacedim>::mapping_collection,
dof,
fe_function,
exact_solution,
difference,
hp::QCollection<dim>(q),
norm,
weight,
exponent);
}
template <int dim, class InVector, class OutVector, int spacedim>
void
integrate_difference(
const dealii::hp::MappingCollection<dim, spacedim> & mapping,
const dealii::DoFHandler<dim, spacedim> & dof,
const InVector & fe_function,
const Function<spacedim, typename InVector::value_type> &exact_solution,
OutVector & difference,
const dealii::hp::QCollection<dim> & q,
const NormType & norm,
const Function<spacedim> * weight,
const double exponent)
{
internal::do_integrate_difference(hp::MappingCollection<dim, spacedim>(
mapping),
dof,
fe_function,
exact_solution,
difference,
q,
norm,
weight,
exponent);
}
template <int dim, class InVector, class OutVector, int spacedim>
void
integrate_difference(
const dealii::DoFHandler<dim, spacedim> & dof,
const InVector & fe_function,
const Function<spacedim, typename InVector::value_type> &exact_solution,
OutVector & difference,
const dealii::hp::QCollection<dim> & q,
const NormType & norm,
const Function<spacedim> * weight,
const double exponent)
{
internal::do_integrate_difference(
hp::StaticMappingQ1<dim, spacedim>::mapping_collection,
dof,
fe_function,
exact_solution,
difference,
q,
norm,
weight,
exponent);
}
template <int dim, int spacedim, class InVector>
double
compute_global_error(const Triangulation<dim, spacedim> &tria,
const InVector & cellwise_error,
const NormType & norm,
const double exponent)
{
Assert(cellwise_error.size() == tria.n_active_cells(),
ExcMessage("input vector cell_error has invalid size!"));
#ifdef DEBUG
{
// check that off-processor entries are zero. Otherwise we will compute
// wrong results below!
typename InVector::size_type i = 0;
typename Triangulation<dim, spacedim>::active_cell_iterator it =
tria.begin_active();
for (; i < cellwise_error.size(); ++i, ++it)
if (!it->is_locally_owned())
Assert(
std::fabs(cellwise_error[i]) < 1e-20,
ExcMessage(
"cellwise_error of cells that are not locally owned need to be zero!"));
}
#endif
const MPI_Comm comm = tria.get_communicator();
switch (norm)
{
case L2_norm:
case H1_seminorm:
case H1_norm:
case Hdiv_seminorm:
{
const double local = cellwise_error.l2_norm();
return std::sqrt(Utilities::MPI::sum(local * local, comm));
}
case L1_norm:
{
const double local = cellwise_error.l1_norm();
return Utilities::MPI::sum(local, comm);
}
case Linfty_norm:
case W1infty_seminorm:
{
const double local = cellwise_error.linfty_norm();
return Utilities::MPI::max(local, comm);
}
case W1infty_norm:
{
AssertThrow(false,
ExcMessage(
"compute_global_error() is impossible for "
"the W1infty_norm. See the documentation for "
"NormType::W1infty_norm for more information."));
return std::numeric_limits<double>::infinity();
}
case mean:
{
// Note: mean is defined as int_\Omega f = sum_K \int_K f, so we
// need the sum of the cellwise errors not the Euclidean mean
// value that is returned by Vector<>::mean_value().
const double local =
cellwise_error.mean_value() * cellwise_error.size();
return Utilities::MPI::sum(local, comm);
}
case Lp_norm:
case W1p_norm:
case W1p_seminorm:
{
double local = 0;
typename InVector::size_type i;
typename Triangulation<dim, spacedim>::active_cell_iterator it =
tria.begin_active();
for (i = 0; i < cellwise_error.size(); ++i, ++it)
if (it->is_locally_owned())
local += std::pow(cellwise_error[i], exponent);
return std::pow(Utilities::MPI::sum(local, comm), 1. / exponent);
}
default:
AssertThrow(false, ExcNotImplemented());
break;
}
return 0.0;
}
} // namespace VectorTools
DEAL_II_NAMESPACE_CLOSE
#endif // dealii_vector_tools_integrate_difference_templates_h