Exemplo n.º 1
0
// ------------------------------------------------------------
// LinearPartitioner implementation
void LinearPartitioner::_do_partition (MeshBase& mesh,
                                       const unsigned int n)
{
  libmesh_assert_greater (n, 0);

  // Check for an easy return
  if (n == 1)
    {
      this->single_partition (mesh);
      return;
    }

  // Create a simple linear partitioning
  {
    START_LOG ("partition()", "LinearPartitioner");

    const dof_id_type n_active_elem = mesh.n_active_elem();
    const dof_id_type blksize       = n_active_elem/n;

    dof_id_type e = 0;

    MeshBase::element_iterator       elem_it  = mesh.active_elements_begin();
    const MeshBase::element_iterator elem_end = mesh.active_elements_end();

    for ( ; elem_it != elem_end; ++elem_it)
      {
        if ((e/blksize) < n)
          {
            Elem *elem = *elem_it;
            elem->processor_id() =
              libmesh_cast_int<processor_id_type>(e/blksize);
          }
        else
          {
            Elem *elem = *elem_it;
            elem->processor_id() = 0;
            elem = elem->parent();
          }

        e++;
      }

    STOP_LOG ("partition()", "LinearPartitioner");
  }
}
Exemplo n.º 2
0
void Partitioner::set_parent_processor_ids(MeshBase & mesh)
{
  // Ignore the parameter when !LIBMESH_ENABLE_AMR
  libmesh_ignore(mesh);

  LOG_SCOPE("set_parent_processor_ids()", "Partitioner");

#ifdef LIBMESH_ENABLE_AMR

  // If the mesh is serial we have access to all the elements,
  // in particular all the active ones.  We can therefore set
  // the parent processor ids indirecly through their children, and
  // set the subactive processor ids while examining their active
  // ancestors.
  // By convention a parent is assigned to the minimum processor
  // of all its children, and a subactive is assigned to the processor
  // of its active ancestor.
  if (mesh.is_serial())
    {
      // Loop over all the active elements in the mesh
      MeshBase::element_iterator       it  = mesh.active_elements_begin();
      const MeshBase::element_iterator end = mesh.active_elements_end();

      for ( ; it!=end; ++it)
        {
          Elem * child  = *it;

          // First set descendents

          std::vector<const Elem *> subactive_family;
          child->total_family_tree(subactive_family);
          for (unsigned int i = 0; i != subactive_family.size(); ++i)
            const_cast<Elem *>(subactive_family[i])->processor_id() = child->processor_id();

          // Then set ancestors

          Elem * parent = child->parent();

          while (parent)
            {
              // invalidate the parent id, otherwise the min below
              // will not work if the current parent id is less
              // than all the children!
              parent->invalidate_processor_id();

              for (unsigned int c=0; c<parent->n_children(); c++)
                {
                  child = parent->child_ptr(c);
                  libmesh_assert(child);
                  libmesh_assert(!child->is_remote());
                  libmesh_assert_not_equal_to (child->processor_id(), DofObject::invalid_processor_id);
                  parent->processor_id() = std::min(parent->processor_id(),
                                                    child->processor_id());
                }
              parent = parent->parent();
            }
        }
    }

  // When the mesh is parallel we cannot guarantee that parents have access to
  // all their children.
  else
    {
      // Setting subactive processor ids is easy: we can guarantee
      // that children have access to all their parents.

      // Loop over all the active elements in the mesh
      MeshBase::element_iterator       it  = mesh.active_elements_begin();
      const MeshBase::element_iterator end = mesh.active_elements_end();

      for ( ; it!=end; ++it)
        {
          Elem * child  = *it;

          std::vector<const Elem *> subactive_family;
          child->total_family_tree(subactive_family);
          for (unsigned int i = 0; i != subactive_family.size(); ++i)
            const_cast<Elem *>(subactive_family[i])->processor_id() = child->processor_id();
        }

      // When the mesh is parallel we cannot guarantee that parents have access to
      // all their children.

      // We will use a brute-force approach here.  Each processor finds its parent
      // elements and sets the parent pid to the minimum of its
      // semilocal descendants.
      // A global reduction is then performed to make sure the true minimum is found.
      // As noted, this is required because we cannot guarantee that a parent has
      // access to all its children on any single processor.
      libmesh_parallel_only(mesh.comm());
      libmesh_assert(MeshTools::n_elem(mesh.unpartitioned_elements_begin(),
                                       mesh.unpartitioned_elements_end()) == 0);

      const dof_id_type max_elem_id = mesh.max_elem_id();

      std::vector<processor_id_type>
        parent_processor_ids (std::min(communication_blocksize,
                                       max_elem_id));

      for (dof_id_type blk=0, last_elem_id=0; last_elem_id<max_elem_id; blk++)
        {
          last_elem_id =
            std::min(static_cast<dof_id_type>((blk+1)*communication_blocksize),
                     max_elem_id);
          const dof_id_type first_elem_id = blk*communication_blocksize;

          std::fill (parent_processor_ids.begin(),
                     parent_processor_ids.end(),
                     DofObject::invalid_processor_id);

          // first build up local contributions to parent_processor_ids
          MeshBase::element_iterator       not_it  = mesh.ancestor_elements_begin();
          const MeshBase::element_iterator not_end = mesh.ancestor_elements_end();

          bool have_parent_in_block = false;

          for ( ; not_it != not_end; ++not_it)
            {
              Elem * parent = *not_it;

              const dof_id_type parent_idx = parent->id();
              libmesh_assert_less (parent_idx, max_elem_id);

              if ((parent_idx >= first_elem_id) &&
                  (parent_idx <  last_elem_id))
                {
                  have_parent_in_block = true;
                  processor_id_type parent_pid = DofObject::invalid_processor_id;

                  std::vector<const Elem *> active_family;
                  parent->active_family_tree(active_family);
                  for (unsigned int i = 0; i != active_family.size(); ++i)
                    parent_pid = std::min (parent_pid, active_family[i]->processor_id());

                  const dof_id_type packed_idx = parent_idx - first_elem_id;
                  libmesh_assert_less (packed_idx, parent_processor_ids.size());

                  parent_processor_ids[packed_idx] = parent_pid;
                }
            }

          // then find the global minimum
          mesh.comm().min (parent_processor_ids);

          // and assign the ids, if we have a parent in this block.
          if (have_parent_in_block)
            for (not_it = mesh.ancestor_elements_begin();
                 not_it != not_end; ++not_it)
              {
                Elem * parent = *not_it;

                const dof_id_type parent_idx = parent->id();

                if ((parent_idx >= first_elem_id) &&
                    (parent_idx <  last_elem_id))
                  {
                    const dof_id_type packed_idx = parent_idx - first_elem_id;
                    libmesh_assert_less (packed_idx, parent_processor_ids.size());

                    const processor_id_type parent_pid =
                      parent_processor_ids[packed_idx];

                    libmesh_assert_not_equal_to (parent_pid, DofObject::invalid_processor_id);

                    parent->processor_id() = parent_pid;
                  }
              }
        }
    }

#endif // LIBMESH_ENABLE_AMR
}
void MeshRefinement::flag_elements_by_elem_fraction (const ErrorVector& error_per_cell,
						     const Real refine_frac,
						     const Real coarsen_frac,
						     const unsigned int max_l)
{
  parallel_only();

  // The function arguments are currently just there for
  // backwards_compatibility
  if (!_use_member_parameters)
  {
    // If the user used non-default parameters, lets warn
    // that they're deprecated
    if (refine_frac != 0.3 ||
	coarsen_frac != 0.0 ||
	max_l != libMesh::invalid_uint)
      libmesh_deprecated();

    _refine_fraction = refine_frac;
    _coarsen_fraction = coarsen_frac;
    _max_h_level = max_l;
  }

  // Check for valid fractions..
  // The fraction values must be in [0,1]
  libmesh_assert_greater_equal (_refine_fraction, 0);
  libmesh_assert_less_equal (_refine_fraction, 1);
  libmesh_assert_greater_equal (_coarsen_fraction, 0);
  libmesh_assert_less_equal (_coarsen_fraction, 1);

  // The number of active elements in the mesh
  const unsigned int n_active_elem  = _mesh.n_elem();

  // The number of elements to flag for coarsening
  const unsigned int n_elem_coarsen =
    static_cast<unsigned int>(_coarsen_fraction * n_active_elem);

  // The number of elements to flag for refinement
  const unsigned int n_elem_refine =
    static_cast<unsigned int>(_refine_fraction  * n_active_elem);



  // Clean up the refinement flags.  These could be left
  // over from previous refinement steps.
  this->clean_refinement_flags();


  // This vector stores the error and element number for all the
  // active elements.  It will be sorted and the top & bottom
  // elements will then be flagged for coarsening & refinement
  std::vector<float> sorted_error;

  sorted_error.reserve (n_active_elem);

  // Loop over the active elements and create the entry
  // in the sorted_error vector
  MeshBase::element_iterator       elem_it  = _mesh.active_local_elements_begin();
  const MeshBase::element_iterator elem_end = _mesh.active_local_elements_end();

  for (; elem_it != elem_end; ++elem_it)
    sorted_error.push_back (error_per_cell[(*elem_it)->id()]);

  CommWorld.allgather(sorted_error);

  // Now sort the sorted_error vector
  std::sort (sorted_error.begin(), sorted_error.end());

  // If we're coarsening by parents:
  // Create a sorted error vector with coarsenable parent elements
  // only, sorted by lowest errors first
  ErrorVector error_per_parent, sorted_parent_error;
  if (_coarsen_by_parents)
  {
    Real parent_error_min, parent_error_max;

    create_parent_error_vector(error_per_cell,
			       error_per_parent,
			       parent_error_min,
			       parent_error_max);

    sorted_parent_error = error_per_parent;
    std::sort (sorted_parent_error.begin(), sorted_parent_error.end());

    // All the other error values will be 0., so get rid of them.
    sorted_parent_error.erase (std::remove(sorted_parent_error.begin(),
					   sorted_parent_error.end(), 0.),
			       sorted_parent_error.end());
  }


  float top_error= 0., bottom_error = 0.;

  // Get the maximum error value corresponding to the
  // bottom n_elem_coarsen elements
  if (_coarsen_by_parents && n_elem_coarsen)
    {
      const unsigned int dim = _mesh.mesh_dimension();
      unsigned int twotodim = 1;
      for (unsigned int i=0; i!=dim; ++i)
        twotodim *= 2;

      unsigned int n_parent_coarsen = n_elem_coarsen / (twotodim - 1);

      if (n_parent_coarsen)
	bottom_error = sorted_parent_error[n_parent_coarsen - 1];
    }
  else if (n_elem_coarsen)
    {
      bottom_error = sorted_error[n_elem_coarsen - 1];
    }

  if (n_elem_refine)
    top_error = sorted_error[sorted_error.size() - n_elem_refine];

  // Finally, let's do the element flagging
  elem_it  = _mesh.active_elements_begin();
  for (; elem_it != elem_end; ++elem_it)
    {
      Elem* elem = *elem_it;
      Elem* parent = elem->parent();

      if (_coarsen_by_parents && parent && n_elem_coarsen &&
          error_per_parent[parent->id()] <= bottom_error)
        elem->set_refinement_flag(Elem::COARSEN);

      if (!_coarsen_by_parents && n_elem_coarsen &&
          error_per_cell[elem->id()] <= bottom_error)
        elem->set_refinement_flag(Elem::COARSEN);

      if (n_elem_refine &&
          elem->level() < _max_h_level &&
          error_per_cell[elem->id()] >= top_error)
        elem->set_refinement_flag(Elem::REFINE);
    }
}
//-----------------------------------------------------------------
// Mesh refinement methods
void MeshRefinement::flag_elements_by_error_fraction (const ErrorVector& error_per_cell,
						      const Real refine_frac,
						      const Real coarsen_frac,
						      const unsigned int max_l)
{
  parallel_only();

  // The function arguments are currently just there for
  // backwards_compatibility
  if (!_use_member_parameters)
  {
    // If the user used non-default parameters, lets warn
    // that they're deprecated
    if (refine_frac != 0.3 ||
	coarsen_frac != 0.0 ||
	max_l != libMesh::invalid_uint)
      libmesh_deprecated();

    _refine_fraction = refine_frac;
    _coarsen_fraction = coarsen_frac;
    _max_h_level = max_l;
  }

  // Check for valid fractions..
  // The fraction values must be in [0,1]
  libmesh_assert_greater_equal (_refine_fraction, 0);
  libmesh_assert_less_equal (_refine_fraction, 1);
  libmesh_assert_greater_equal (_coarsen_fraction, 0);
  libmesh_assert_less_equal (_coarsen_fraction, 1);

  // Clean up the refinement flags.  These could be left
  // over from previous refinement steps.
  this->clean_refinement_flags();

  // We're getting the minimum and maximum error values
  // for the ACTIVE elements
  Real error_min = 1.e30;
  Real error_max = 0.;

  // And, if necessary, for their parents
  Real parent_error_min = 1.e30;
  Real parent_error_max = 0.;

  // Prepare another error vector if we need to sum parent errors
  ErrorVector error_per_parent;
  if (_coarsen_by_parents)
  {
    create_parent_error_vector(error_per_cell,
			       error_per_parent,
			       parent_error_min,
			       parent_error_max);
  }

  // We need to loop over all active elements to find the minimum
  MeshBase::element_iterator       el_it  =
    _mesh.active_local_elements_begin();
  const MeshBase::element_iterator el_end =
    _mesh.active_local_elements_end();

  for (; el_it != el_end; ++el_it)
  {
    const unsigned int id  = (*el_it)->id();
    libmesh_assert_less (id, error_per_cell.size());

    error_max = std::max (error_max, error_per_cell[id]);
    error_min = std::min (error_min, error_per_cell[id]);
  }
  CommWorld.max(error_max);
  CommWorld.min(error_min);

  // Compute the cutoff values for coarsening and refinement
  const Real error_delta = (error_max - error_min);
  const Real parent_error_delta = parent_error_max - parent_error_min;

  const Real refine_cutoff  = (1.- _refine_fraction)*error_max;
  const Real coarsen_cutoff = _coarsen_fraction*error_delta + error_min;
  const Real parent_cutoff = _coarsen_fraction*parent_error_delta + error_min;

//   // Print information about the error
//   libMesh::out << " Error Information:"                     << std::endl
// 	    << " ------------------"                     << std::endl
// 	    << "   min:              " << error_min      << std::endl
// 	    << "   max:              " << error_max      << std::endl
// 	    << "   delta:            " << error_delta    << std::endl
// 	    << "     refine_cutoff:  " << refine_cutoff  << std::endl
// 	    << "     coarsen_cutoff: " << coarsen_cutoff << std::endl;



  // Loop over the elements and flag them for coarsening or
  // refinement based on the element error

  MeshBase::element_iterator       e_it  =
    _mesh.active_elements_begin();
  const MeshBase::element_iterator e_end =
    _mesh.active_elements_end();
  for (; e_it != e_end; ++e_it)
  {
    Elem* elem             = *e_it;
    const unsigned int id  = elem->id();

    libmesh_assert_less (id, error_per_cell.size());

    const float elem_error = error_per_cell[id];

    if (_coarsen_by_parents)
    {
      Elem* parent           = elem->parent();
      if (parent)
      {
	const unsigned int parentid  = parent->id();
	if (error_per_parent[parentid] >= 0. &&
	    error_per_parent[parentid] <= parent_cutoff)
	  elem->set_refinement_flag(Elem::COARSEN);
      }
    }
    // Flag the element for coarsening if its error
    // is <= coarsen_fraction*delta + error_min
    else if (elem_error <= coarsen_cutoff)
    {
      elem->set_refinement_flag(Elem::COARSEN);
    }

    // Flag the element for refinement if its error
    // is >= refinement_cutoff.
    if (elem_error >= refine_cutoff)
      if (elem->level() < _max_h_level)
	elem->set_refinement_flag(Elem::REFINE);
  }
}
void MeshRefinement::flag_elements_by_error_tolerance (const ErrorVector& error_per_cell_in)
{
  parallel_only();

  libmesh_assert_greater (_coarsen_threshold, 0);

  // Check for valid fractions..
  // The fraction values must be in [0,1]
  libmesh_assert_greater_equal (_refine_fraction, 0);
  libmesh_assert_less_equal (_refine_fraction, 1);
  libmesh_assert_greater_equal (_coarsen_fraction, 0);
  libmesh_assert_less_equal (_coarsen_fraction, 1);

  // How much error per cell will we tolerate?
  const Real local_refinement_tolerance =
    _absolute_global_tolerance / std::sqrt(static_cast<Real>(_mesh.n_active_elem()));
  const Real local_coarsening_tolerance =
    local_refinement_tolerance * _coarsen_threshold;

  // Prepare another error vector if we need to sum parent errors
  ErrorVector error_per_parent;
  if (_coarsen_by_parents)
  {
    Real parent_error_min, parent_error_max;

    create_parent_error_vector(error_per_cell_in,
			       error_per_parent,
			       parent_error_min,
			       parent_error_max);
  }

  MeshBase::element_iterator       elem_it  = _mesh.active_elements_begin();
  const MeshBase::element_iterator elem_end = _mesh.active_elements_end();

  for (; elem_it != elem_end; ++elem_it)
  {
    Elem* elem = *elem_it;
    Elem* parent = elem->parent();
    const unsigned int elem_number = elem->id();
    const float        elem_error  = error_per_cell_in[elem_number];

    if (elem_error > local_refinement_tolerance &&
	elem->level() < _max_h_level)
      elem->set_refinement_flag(Elem::REFINE);

    if (!_coarsen_by_parents && elem_error <
	local_coarsening_tolerance)
      elem->set_refinement_flag(Elem::COARSEN);

    if (_coarsen_by_parents && parent)
    {
      float parent_error = error_per_parent[parent->id()];
      if (parent_error >= 0.)
      {
	const Real parent_coarsening_tolerance =
	  std::sqrt(parent->n_children() *
		    local_coarsening_tolerance *
		    local_coarsening_tolerance);
	if (parent_error < parent_coarsening_tolerance)
	  elem->set_refinement_flag(Elem::COARSEN);
      }
    }
  }
}
Exemplo n.º 6
0
bool UnstructuredMesh::contract ()
{
  LOG_SCOPE ("contract()", "Mesh");

  // Flag indicating if this call actually changes the mesh
  bool mesh_changed = false;

  element_iterator in        = elements_begin();
  const element_iterator end = elements_end();

#ifdef DEBUG
  for ( ; in != end; ++in)
    if (*in != libmesh_nullptr)
      {
        Elem * el = *in;
        libmesh_assert(el->active() || el->subactive() || el->ancestor());
      }
  in = elements_begin();
#endif

  // Loop over the elements.
  for ( ; in != end; ++in)
    if (*in != libmesh_nullptr)
      {
        Elem * el = *in;

        // Delete all the subactive ones
        if (el->subactive())
          {
            // No level-0 element should be subactive.
            // Note that we CAN'T test elem->level(), as that
            // touches elem->parent()->dim(), and elem->parent()
            // might have already been deleted!
            libmesh_assert(el->parent());

            // Delete the element
            // This just sets a pointer to NULL, and doesn't
            // invalidate any iterators
            this->delete_elem(el);

            // the mesh has certainly changed
            mesh_changed = true;
          }
        else
          {
            // Compress all the active ones
            if (el->active())
              el->contract();
            else
              libmesh_assert (el->ancestor());
          }
      }

  // Strip any newly-created NULL voids out of the element array
  this->renumber_nodes_and_elements();

  // FIXME: Need to understand why deleting subactive children
  // invalidates the point locator.  For now we will clear it explicitly
  this->clear_point_locator();

  return mesh_changed;
}
Exemplo n.º 7
0
void unpack(std::vector<largest_id_type>::const_iterator in,
            Elem** out,
            MeshBase* mesh)
{
#ifndef NDEBUG
  const std::vector<largest_id_type>::const_iterator original_in = in;

  const largest_id_type incoming_header = *in++;
  libmesh_assert_equal_to (incoming_header, elem_magic_header);
#endif

  // int 0: level
  const unsigned int level =
    static_cast<unsigned int>(*in++);

#ifdef LIBMESH_ENABLE_AMR
  // int 1: p level
  const unsigned int p_level =
    static_cast<unsigned int>(*in++);

  // int 2: refinement flag
  const int rflag = *in++;
  libmesh_assert_greater_equal (rflag, 0);
  libmesh_assert_less (rflag, Elem::INVALID_REFINEMENTSTATE);
  const Elem::RefinementState refinement_flag =
    static_cast<Elem::RefinementState>(rflag);

  // int 3: p refinement flag
  const int pflag = *in++;
  libmesh_assert_greater_equal (pflag, 0);
  libmesh_assert_less (pflag, Elem::INVALID_REFINEMENTSTATE);
  const Elem::RefinementState p_refinement_flag =
    static_cast<Elem::RefinementState>(pflag);
#else
  in += 3;
#endif // LIBMESH_ENABLE_AMR

  // int 4: element type
  const int typeint = *in++;
  libmesh_assert_greater_equal (typeint, 0);
  libmesh_assert_less (typeint, INVALID_ELEM);
  const ElemType type =
    static_cast<ElemType>(typeint);

  const unsigned int n_nodes =
    Elem::type_to_n_nodes_map[type];

  // int 5: processor id
  const processor_id_type processor_id =
    static_cast<processor_id_type>(*in++);
  libmesh_assert (processor_id < mesh->n_processors() ||
                  processor_id == DofObject::invalid_processor_id);

  // int 6: subdomain id
  const subdomain_id_type subdomain_id =
    static_cast<subdomain_id_type>(*in++);

  // int 7: dof object id
  const dof_id_type id =
    static_cast<dof_id_type>(*in++);
  libmesh_assert_not_equal_to (id, DofObject::invalid_id);

#ifdef LIBMESH_ENABLE_UNIQUE_ID
  // int 8: dof object unique id
  const unique_id_type unique_id =
    static_cast<unique_id_type>(*in++);
#endif

#ifdef LIBMESH_ENABLE_AMR
  // int 9: parent dof object id
  const dof_id_type parent_id =
    static_cast<dof_id_type>(*in++);
  libmesh_assert (level == 0 || parent_id != DofObject::invalid_id);
  libmesh_assert (level != 0 || parent_id == DofObject::invalid_id);

  // int 10: local child id
  const unsigned int which_child_am_i =
    static_cast<unsigned int>(*in++);
#else
  in += 2;
#endif // LIBMESH_ENABLE_AMR

  // Make sure we don't miscount above when adding the "magic" header
  // plus the real data header
  libmesh_assert_equal_to (in - original_in, header_size + 1);

  Elem *elem = mesh->query_elem(id);

  // if we already have this element, make sure its
  // properties match, and update any missing neighbor
  // links, but then go on
  if (elem)
    {
      libmesh_assert_equal_to (elem->level(), level);
      libmesh_assert_equal_to (elem->id(), id);
//#ifdef LIBMESH_ENABLE_UNIQUE_ID
      // No check for unqiue id sanity
//#endif
      libmesh_assert_equal_to (elem->processor_id(), processor_id);
      libmesh_assert_equal_to (elem->subdomain_id(), subdomain_id);
      libmesh_assert_equal_to (elem->type(), type);
      libmesh_assert_equal_to (elem->n_nodes(), n_nodes);

#ifndef NDEBUG
      // All our nodes should be correct
      for (unsigned int i=0; i != n_nodes; ++i)
        libmesh_assert(elem->node(i) ==
                       static_cast<dof_id_type>(*in++));
#else
      in += n_nodes;
#endif

#ifdef LIBMESH_ENABLE_AMR
      libmesh_assert_equal_to (elem->p_level(), p_level);
      libmesh_assert_equal_to (elem->refinement_flag(), refinement_flag);
      libmesh_assert_equal_to (elem->p_refinement_flag(), p_refinement_flag);

      libmesh_assert (!level || elem->parent() != NULL);
      libmesh_assert (!level || elem->parent()->id() == parent_id);
      libmesh_assert (!level || elem->parent()->child(which_child_am_i) == elem);
#endif

      // Our neighbor links should be "close to" correct - we may have
      // to update them, but we can check for some inconsistencies.
      for (unsigned int n=0; n != elem->n_neighbors(); ++n)
        {
          const dof_id_type neighbor_id =
            static_cast<dof_id_type>(*in++);

	  // If the sending processor sees a domain boundary here,
	  // we'd better agree.
          if (neighbor_id == DofObject::invalid_id)
            {
              libmesh_assert (!(elem->neighbor(n)));
              continue;
            }

	  // If the sending processor has a remote_elem neighbor here,
	  // then all we know is that we'd better *not* have a domain
	  // boundary.
          if (neighbor_id == remote_elem->id())
            {
              libmesh_assert(elem->neighbor(n));
              continue;
            }

          Elem *neigh = mesh->query_elem(neighbor_id);

          // The sending processor sees a neighbor here, so if we
          // don't have that neighboring element, then we'd better
          // have a remote_elem signifying that fact.
          if (!neigh)
            {
              libmesh_assert_equal_to (elem->neighbor(n), remote_elem);
              continue;
            }

          // The sending processor has a neighbor here, and we have
          // that element, but that does *NOT* mean we're already
	  // linking to it.  Perhaps we initially received both elem
	  // and neigh from processors on which their mutual link was
	  // remote?
          libmesh_assert(elem->neighbor(n) == neigh ||
			 elem->neighbor(n) == remote_elem);

	  // If the link was originally remote, we should update it,
	  // and make sure the appropriate parts of its family link
	  // back to us.
	  if (elem->neighbor(n) == remote_elem)
            {
              elem->set_neighbor(n, neigh);

              elem->make_links_to_me_local(n);
	    }
	}

      // FIXME: We should add some debug mode tests to ensure that the
      // encoded indexing and boundary conditions are consistent.
    }
  else
    {
      // We don't already have the element, so we need to create it.

      // Find the parent if necessary
      Elem *parent = NULL;
#ifdef LIBMESH_ENABLE_AMR
      // Find a child element's parent
      if (level > 0)
        {
	  // Note that we must be very careful to construct the send
	  // connectivity so that parents are encountered before
	  // children.  If we get here and can't find the parent that
	  // is a fatal error.
          parent = mesh->elem(parent_id);
        }
      // Or assert that the sending processor sees no parent
      else
        libmesh_assert_equal_to (parent_id, static_cast<dof_id_type>(-1));
#else
      // No non-level-0 elements without AMR
      libmesh_assert_equal_to (level, 0);
#endif

      elem = Elem::build(type,parent).release();
      libmesh_assert (elem);

#ifdef LIBMESH_ENABLE_AMR
      if (level != 0)
        {
          // Since this is a newly created element, the parent must
          // have previously thought of this child as a remote element.
          libmesh_assert_equal_to (parent->child(which_child_am_i), remote_elem);

          parent->add_child(elem, which_child_am_i);
        }

      // Assign the refinement flags and levels
      elem->set_p_level(p_level);
      elem->set_refinement_flag(refinement_flag);
      elem->set_p_refinement_flag(p_refinement_flag);
      libmesh_assert_equal_to (elem->level(), level);

      // If this element definitely should have children, assign
      // remote_elem to all of them for now, for consistency.  Later
      // unpacked elements may overwrite that.
      if (!elem->active())
        for (unsigned int c=0; c != elem->n_children(); ++c)
          elem->add_child(const_cast<RemoteElem*>(remote_elem), c);

#endif // LIBMESH_ENABLE_AMR

      // Assign the IDs
      elem->subdomain_id()  = subdomain_id;
      elem->processor_id()  = processor_id;
      elem->set_id()        = id;
#ifdef LIBMESH_ENABLE_UNIQUE_ID
      elem->set_unique_id() = unique_id;
#endif

      // Assign the connectivity
      libmesh_assert_equal_to (elem->n_nodes(), n_nodes);

      for (unsigned int n=0; n != n_nodes; n++)
        elem->set_node(n) =
          mesh->node_ptr
	    (static_cast<dof_id_type>(*in++));

      for (unsigned int n=0; n<elem->n_neighbors(); n++)
        {
          const dof_id_type neighbor_id =
            static_cast<dof_id_type>(*in++);

          if (neighbor_id == DofObject::invalid_id)
	    continue;

          // We may be unpacking an element that was a ghost element on the
          // sender, in which case the element's neighbors may not all be
          // known by the packed element.  We'll have to set such
          // neighbors to remote_elem ourselves and wait for a later
          // packed element to give us better information.
          if (neighbor_id == remote_elem->id())
            {
              elem->set_neighbor(n, const_cast<RemoteElem*>(remote_elem));
	      continue;
	    }

          // If we don't have the neighbor element, then it's a
          // remote_elem until we get it.
          Elem *neigh = mesh->query_elem(neighbor_id);
          if (!neigh)
            {
              elem->set_neighbor(n, const_cast<RemoteElem*>(remote_elem));
	      continue;
	    }

          // If we have the neighbor element, then link to it, and
          // make sure the appropriate parts of its family link back
          // to us.
          elem->set_neighbor(n, neigh);

          elem->make_links_to_me_local(n);
        }

      elem->unpack_indexing(in);
    }

  in += elem->packed_indexing_size();

  // If this is a coarse element,
  // add any element side boundary condition ids
  if (level == 0)
    for (unsigned int s = 0; s != elem->n_sides(); ++s)
      {
        const int num_bcs = *in++;
        libmesh_assert_greater_equal (num_bcs, 0);

        for(int bc_it=0; bc_it < num_bcs; bc_it++)
          mesh->boundary_info->add_side (elem, s, *in++);
      }

  // Return the new element
  *out = elem;
}
bool MeshRefinement::eliminate_unrefined_patches ()
{
  // This function must be run on all processors at once
  parallel_only();

  bool flags_changed = false;

  MeshBase::element_iterator       elem_it  = _mesh.active_elements_begin();
  const MeshBase::element_iterator elem_end = _mesh.active_elements_end();

  for (; elem_it != elem_end; ++elem_it)
    {
      Elem* elem = *elem_it;
      // First assume that we'll have to flag this element for both h
      // and p refinement, then change our minds if we see any
      // neighbors that are as coarse or coarser than us.
      bool h_flag_me = true,
           p_flag_me = true;


      // Skip the element if it is already fully flagged for refinement
      if (elem->p_refinement_flag() == Elem::REFINE)
	p_flag_me = false;
      if (elem->refinement_flag() == Elem::REFINE)
        {
          h_flag_me = false;
          if (!p_flag_me)
            continue;
        }
      // Test the parent if that is already flagged for coarsening
      else if (elem->refinement_flag() == Elem::COARSEN)
        {
          libmesh_assert(elem->parent());
	  elem = elem->parent();
          // FIXME - this doesn't seem right - RHS
          if (elem->refinement_flag() != Elem::COARSEN_INACTIVE)
            continue;
          p_flag_me = false;
        }

      const unsigned int my_level = elem->level();
      int my_p_adjustment = 0;
      if (elem->p_refinement_flag() == Elem::REFINE)
        my_p_adjustment = 1;
      else if (elem->p_refinement_flag() == Elem::COARSEN)
        {
          libmesh_assert_greater (elem->p_level(), 0);
          my_p_adjustment = -1;
        }
      const unsigned int my_new_p_level = elem->p_level() +
                                          my_p_adjustment;

      // Check all the element neighbors
      for (unsigned int n=0; n<elem->n_neighbors(); n++)
        {
          const Elem *neighbor = elem->neighbor(n);
	  // Quit if the element is on a local boundary
	  if (neighbor == NULL || neighbor == remote_elem)
            {
              h_flag_me = false;
              p_flag_me = false;
              break;
            }
          // if the neighbor will be equally or less refined than
	  // we are, then we will not become an unrefined island.
          // So if we are still considering h refinement:
          if (h_flag_me &&
            // If our neighbor is already at a lower level,
            // it can't end up at a higher level even if it
            // is flagged for refinement once
             ((neighbor->level() < my_level) ||
            // If our neighbor is at the same level but isn't
            // flagged for refinement, it won't end up at a
            // higher level
             ((neighbor->active()) &&
              (neighbor->refinement_flag() != Elem::REFINE)) ||
            // If our neighbor is currently more refined but is
            // a parent flagged for coarsening, it will end up
            // at the same level.
             (neighbor->refinement_flag() == Elem::COARSEN_INACTIVE)))
            {
              // We've proven we won't become an unrefined island,
              // so don't h refine to avoid that.
	      h_flag_me = false;

              // If we've also proven we don't need to p refine,
              // we don't need to check more neighbors
              if (!p_flag_me)
                break;
            }
	  if (p_flag_me)
            {
	      // if active neighbors will have a p level
	      // equal to or lower than ours, then we do not need to p
              // refine ourselves.
              if (neighbor->active())
                {
                  int p_adjustment = 0;
                  if (neighbor->p_refinement_flag() == Elem::REFINE)
                    p_adjustment = 1;
                  else if (neighbor->p_refinement_flag() == Elem::COARSEN)
                    {
                      libmesh_assert_greater (neighbor->p_level(), 0);
                      p_adjustment = -1;
                    }
                  if (my_new_p_level >= neighbor->p_level() + p_adjustment)
                    {
                      p_flag_me = false;
                      if (!h_flag_me)
                        break;
                    }
                }
              // If we have inactive neighbors, we need to
              // test all their active descendants which neighbor us
              else if (neighbor->ancestor())
                {
                  if (neighbor->min_new_p_level_by_neighbor(elem,
                      my_new_p_level + 2) <= my_new_p_level)
                    {
                      p_flag_me = false;
                      if (!h_flag_me)
                        break;
                    }
                }
            }
        }

      if (h_flag_me)
	{
	  // Parents that would create islands should no longer
          // coarsen
          if (elem->refinement_flag() == Elem::COARSEN_INACTIVE)
            {
              for (unsigned int c=0; c<elem->n_children(); c++)
                {
                  libmesh_assert_equal_to (elem->child(c)->refinement_flag(),
                                          Elem::COARSEN);
                  elem->child(c)->set_refinement_flag(Elem::DO_NOTHING);
                }
              elem->set_refinement_flag(Elem::INACTIVE);
            }
          else
	    elem->set_refinement_flag(Elem::REFINE);
	  flags_changed = true;
	}
      if (p_flag_me)
	{
          if (elem->p_refinement_flag() == Elem::COARSEN)
	    elem->set_p_refinement_flag(Elem::DO_NOTHING);
          else
	    elem->set_p_refinement_flag(Elem::REFINE);
	  flags_changed = true;
	}
    }

  // If flags changed on any processor then they changed globally
  CommWorld.max(flags_changed);

  return flags_changed;
}
Exemplo n.º 9
0
Elem *
Packing<Elem *>::unpack (std::vector<largest_id_type>::const_iterator in,
                         MeshBase * mesh)
{
#ifndef NDEBUG
  const std::vector<largest_id_type>::const_iterator original_in = in;

  const largest_id_type incoming_header = *in++;
  libmesh_assert_equal_to (incoming_header, elem_magic_header);
#endif

  // int 0: level
  const unsigned int level =
    cast_int<unsigned int>(*in++);

#ifdef LIBMESH_ENABLE_AMR
  // int 1: p level
  const unsigned int p_level =
    cast_int<unsigned int>(*in++);

  // int 2: refinement flag and encoded has_children
  const int rflag = cast_int<int>(*in++);
  const int invalid_rflag =
    cast_int<int>(Elem::INVALID_REFINEMENTSTATE);
  libmesh_assert_greater_equal (rflag, 0);

  libmesh_assert_less (rflag, invalid_rflag*2+1);

  const bool has_children = (rflag > invalid_rflag);

  const Elem::RefinementState refinement_flag = has_children ?
    cast_int<Elem::RefinementState>(rflag - invalid_rflag - 1) :
    cast_int<Elem::RefinementState>(rflag);

  // int 3: p refinement flag
  const int pflag = cast_int<int>(*in++);
  libmesh_assert_greater_equal (pflag, 0);
  libmesh_assert_less (pflag, Elem::INVALID_REFINEMENTSTATE);
  const Elem::RefinementState p_refinement_flag =
    cast_int<Elem::RefinementState>(pflag);
#else
  in += 3;
#endif // LIBMESH_ENABLE_AMR

  // int 4: element type
  const int typeint = cast_int<int>(*in++);
  libmesh_assert_greater_equal (typeint, 0);
  libmesh_assert_less (typeint, INVALID_ELEM);
  const ElemType type =
    cast_int<ElemType>(typeint);

  const unsigned int n_nodes =
    Elem::type_to_n_nodes_map[type];

  // int 5: processor id
  const processor_id_type processor_id =
    cast_int<processor_id_type>(*in++);
  libmesh_assert (processor_id < mesh->n_processors() ||
                  processor_id == DofObject::invalid_processor_id);

  // int 6: subdomain id
  const subdomain_id_type subdomain_id =
    cast_int<subdomain_id_type>(*in++);

  // int 7: dof object id
  const dof_id_type id =
    cast_int<dof_id_type>(*in++);
  libmesh_assert_not_equal_to (id, DofObject::invalid_id);

#ifdef LIBMESH_ENABLE_UNIQUE_ID
  // int 8: dof object unique id
  const unique_id_type unique_id =
    cast_int<unique_id_type>(*in++);
#endif

#ifdef LIBMESH_ENABLE_AMR
  // int 9: parent dof object id.
  // Note: If level==0, then (*in) == invalid_id.  In
  // this case, the equality check in cast_int<unsigned>(*in) will
  // never succeed.  Therefore, we should only attempt the more
  // rigorous cast verification in cases where level != 0.
  const dof_id_type parent_id =
    (level == 0)
    ? static_cast<dof_id_type>(*in++)
    : cast_int<dof_id_type>(*in++);
  libmesh_assert (level == 0 || parent_id != DofObject::invalid_id);
  libmesh_assert (level != 0 || parent_id == DofObject::invalid_id);

  // int 10: local child id
  // Note: If level==0, then which_child_am_i is not valid, so don't
  // do the more rigorous cast verification.
  const unsigned int which_child_am_i =
    (level == 0)
    ? static_cast<unsigned int>(*in++)
    : cast_int<unsigned int>(*in++);
#else
  in += 2;
#endif // LIBMESH_ENABLE_AMR

  const dof_id_type interior_parent_id =
    static_cast<dof_id_type>(*in++);

  // Make sure we don't miscount above when adding the "magic" header
  // plus the real data header
  libmesh_assert_equal_to (in - original_in, header_size + 1);

  Elem * elem = mesh->query_elem_ptr(id);

  // if we already have this element, make sure its
  // properties match, and update any missing neighbor
  // links, but then go on
  if (elem)
    {
      libmesh_assert_equal_to (elem->level(), level);
      libmesh_assert_equal_to (elem->id(), id);
      //#ifdef LIBMESH_ENABLE_UNIQUE_ID
      // No check for unique id sanity
      //#endif
      libmesh_assert_equal_to (elem->processor_id(), processor_id);
      libmesh_assert_equal_to (elem->subdomain_id(), subdomain_id);
      libmesh_assert_equal_to (elem->type(), type);
      libmesh_assert_equal_to (elem->n_nodes(), n_nodes);

#ifndef NDEBUG
      // All our nodes should be correct
      for (unsigned int i=0; i != n_nodes; ++i)
        libmesh_assert(elem->node_id(i) ==
                       cast_int<dof_id_type>(*in++));
#else
      in += n_nodes;
#endif

#ifdef LIBMESH_ENABLE_AMR
      libmesh_assert_equal_to (elem->refinement_flag(), refinement_flag);
      libmesh_assert_equal_to (elem->has_children(), has_children);

#ifdef DEBUG
      if (elem->active())
        {
          libmesh_assert_equal_to (elem->p_level(), p_level);
          libmesh_assert_equal_to (elem->p_refinement_flag(), p_refinement_flag);
        }
#endif

      libmesh_assert (!level || elem->parent() != libmesh_nullptr);
      libmesh_assert (!level || elem->parent()->id() == parent_id);
      libmesh_assert (!level || elem->parent()->child_ptr(which_child_am_i) == elem);
#endif
      // Our interior_parent link should be "close to" correct - we
      // may have to update it, but we can check for some
      // inconsistencies.
      {
        // If the sending processor sees no interior_parent here, we'd
        // better agree.
        if (interior_parent_id == DofObject::invalid_id)
          {
            if (elem->dim() < LIBMESH_DIM)
              libmesh_assert (!(elem->interior_parent()));
          }

        // If the sending processor has a remote_elem interior_parent,
        // then all we know is that we'd better have *some*
        // interior_parent
        else if (interior_parent_id == remote_elem->id())
          {
            libmesh_assert(elem->interior_parent());
          }
        else
          {
            Elem * ip = mesh->query_elem_ptr(interior_parent_id);

            // The sending processor sees an interior parent here, so
            // if we don't have that interior element, then we'd
            // better have a remote_elem signifying that fact.
            if (!ip)
              libmesh_assert_equal_to (elem->interior_parent(), remote_elem);
            else
              {
                // The sending processor has an interior_parent here,
                // and we have that element, but that does *NOT* mean
                // we're already linking to it.  Perhaps we initially
                // received elem from a processor on which the
                // interior_parent link was remote?
                libmesh_assert(elem->interior_parent() == ip ||
                               elem->interior_parent() == remote_elem);

                // If the link was originally remote, update it
                if (elem->interior_parent() == remote_elem)
                  {
                    elem->set_interior_parent(ip);
                  }
              }
          }
      }

      // Our neighbor links should be "close to" correct - we may have
      // to update a remote_elem link, and we can check for possible
      // inconsistencies along the way.
      //
      // For subactive elements, we don't bother keeping neighbor
      // links in good shape, so there's nothing we need to set or can
      // safely assert here.
      if (!elem->subactive())
        for (auto n : elem->side_index_range())
          {
            const dof_id_type neighbor_id =
              cast_int<dof_id_type>(*in++);

            // If the sending processor sees a domain boundary here,
            // we'd better agree.
            if (neighbor_id == DofObject::invalid_id)
              {
                libmesh_assert (!(elem->neighbor_ptr(n)));
                continue;
              }

            // If the sending processor has a remote_elem neighbor here,
            // then all we know is that we'd better *not* have a domain
            // boundary.
            if (neighbor_id == remote_elem->id())
              {
                libmesh_assert(elem->neighbor_ptr(n));
                continue;
              }

            Elem * neigh = mesh->query_elem_ptr(neighbor_id);

            // The sending processor sees a neighbor here, so if we
            // don't have that neighboring element, then we'd better
            // have a remote_elem signifying that fact.
            if (!neigh)
              {
                libmesh_assert_equal_to (elem->neighbor_ptr(n), remote_elem);
                continue;
              }

            // The sending processor has a neighbor here, and we have
            // that element, but that does *NOT* mean we're already
            // linking to it.  Perhaps we initially received both elem
            // and neigh from processors on which their mutual link was
            // remote?
            libmesh_assert(elem->neighbor_ptr(n) == neigh ||
                           elem->neighbor_ptr(n) == remote_elem);

            // If the link was originally remote, we should update it,
            // and make sure the appropriate parts of its family link
            // back to us.
            if (elem->neighbor_ptr(n) == remote_elem)
              {
                elem->set_neighbor(n, neigh);

                elem->make_links_to_me_local(n);
              }
          }

      // Our p level and refinement flags should be "close to" correct
      // if we're not an active element - we might have a p level
      // increased or decreased by changes in remote_elem children.
      //
      // But if we have remote_elem children, then we shouldn't be
      // doing a projection on this inactive element on this
      // processor, so we won't need correct p settings.  Couldn't
      // hurt to update, though.
#ifdef LIBMESH_ENABLE_AMR
      if (elem->processor_id() != mesh->processor_id())
        {
          elem->hack_p_level(p_level);
          elem->set_p_refinement_flag(p_refinement_flag);
        }
#endif // LIBMESH_ENABLE_AMR

      // FIXME: We should add some debug mode tests to ensure that the
      // encoded indexing and boundary conditions are consistent.
    }
  else
    {
      // We don't already have the element, so we need to create it.

      // Find the parent if necessary
      Elem * parent = libmesh_nullptr;
#ifdef LIBMESH_ENABLE_AMR
      // Find a child element's parent
      if (level > 0)
        {
          // Note that we must be very careful to construct the send
          // connectivity so that parents are encountered before
          // children.  If we get here and can't find the parent that
          // is a fatal error.
          parent = mesh->elem_ptr(parent_id);
        }
      // Or assert that the sending processor sees no parent
      else
        libmesh_assert_equal_to (parent_id, DofObject::invalid_id);
#else
      // No non-level-0 elements without AMR
      libmesh_assert_equal_to (level, 0);
#endif

      elem = Elem::build(type,parent).release();
      libmesh_assert (elem);

#ifdef LIBMESH_ENABLE_AMR
      if (level != 0)
        {
          // Since this is a newly created element, the parent must
          // have previously thought of this child as a remote element.
          libmesh_assert_equal_to (parent->child_ptr(which_child_am_i), remote_elem);

          parent->add_child(elem, which_child_am_i);
        }

      // Assign the refinement flags and levels
      elem->set_p_level(p_level);
      elem->set_refinement_flag(refinement_flag);
      elem->set_p_refinement_flag(p_refinement_flag);
      libmesh_assert_equal_to (elem->level(), level);

      // If this element should have children, assign remote_elem to
      // all of them for now, for consistency.  Later unpacked
      // elements may overwrite that.
      if (has_children)
        {
          const unsigned int nc = elem->n_children();
          for (unsigned int c=0; c != nc; ++c)
            elem->add_child(const_cast<RemoteElem *>(remote_elem), c);
        }

#endif // LIBMESH_ENABLE_AMR

      // Assign the IDs
      elem->subdomain_id()  = subdomain_id;
      elem->processor_id()  = processor_id;
      elem->set_id()        = id;
#ifdef LIBMESH_ENABLE_UNIQUE_ID
      elem->set_unique_id() = unique_id;
#endif

      // Assign the connectivity
      libmesh_assert_equal_to (elem->n_nodes(), n_nodes);

      for (unsigned int n=0; n != n_nodes; n++)
        elem->set_node(n) =
          mesh->node_ptr
          (cast_int<dof_id_type>(*in++));

      // Set interior_parent if found
      {
        // We may be unpacking an element that was a ghost element on the
        // sender, in which case the element's interior_parent may not be
        // known by the packed element.  We'll have to set such
        // interior_parents to remote_elem ourselves and wait for a
        // later packed element to give us better information.
        if (interior_parent_id == remote_elem->id())
          {
            elem->set_interior_parent
              (const_cast<RemoteElem *>(remote_elem));
          }
        else if (interior_parent_id != DofObject::invalid_id)
          {
            // If we don't have the interior parent element, then it's
            // a remote_elem until we get it.
            Elem * ip = mesh->query_elem_ptr(interior_parent_id);
            if (!ip )
              elem->set_interior_parent
                (const_cast<RemoteElem *>(remote_elem));
            else
              elem->set_interior_parent(ip);
          }
      }

      for (auto n : elem->side_index_range())
        {
          const dof_id_type neighbor_id =
            cast_int<dof_id_type>(*in++);

          if (neighbor_id == DofObject::invalid_id)
            continue;

          // We may be unpacking an element that was a ghost element on the
          // sender, in which case the element's neighbors may not all be
          // known by the packed element.  We'll have to set such
          // neighbors to remote_elem ourselves and wait for a later
          // packed element to give us better information.
          if (neighbor_id == remote_elem->id())
            {
              elem->set_neighbor(n, const_cast<RemoteElem *>(remote_elem));
              continue;
            }

          // If we don't have the neighbor element, then it's a
          // remote_elem until we get it.
          Elem * neigh = mesh->query_elem_ptr(neighbor_id);
          if (!neigh)
            {
              elem->set_neighbor(n, const_cast<RemoteElem *>(remote_elem));
              continue;
            }

          // If we have the neighbor element, then link to it, and
          // make sure the appropriate parts of its family link back
          // to us.
          elem->set_neighbor(n, neigh);

          elem->make_links_to_me_local(n);
        }

      elem->unpack_indexing(in);
    }

  in += elem->packed_indexing_size();

  // If this is a coarse element,
  // add any element side or edge boundary condition ids
  if (level == 0)
    {
      for (auto s : elem->side_index_range())
        {
          const boundary_id_type num_bcs =
            cast_int<boundary_id_type>(*in++);

          for (boundary_id_type bc_it=0; bc_it < num_bcs; bc_it++)
            mesh->get_boundary_info().add_side
              (elem, s, cast_int<boundary_id_type>(*in++));
        }

      for (auto e : elem->edge_index_range())
        {
          const boundary_id_type num_bcs =
            cast_int<boundary_id_type>(*in++);

          for (boundary_id_type bc_it=0; bc_it < num_bcs; bc_it++)
            mesh->get_boundary_info().add_edge
              (elem, e, cast_int<boundary_id_type>(*in++));
        }

      for (unsigned short sf=0; sf != 2; ++sf)
        {
          const boundary_id_type num_bcs =
            cast_int<boundary_id_type>(*in++);

          for (boundary_id_type bc_it=0; bc_it < num_bcs; bc_it++)
            mesh->get_boundary_info().add_shellface
              (elem, sf, cast_int<boundary_id_type>(*in++));
        }
    }

  // Return the new element
  return elem;
}