void
MultiAppProjectionTransfer::toMultiApp()
{
Moose::out << "Projecting solution" << std::endl;
for (unsigned int app = 0; app < _multi_app->numGlobalApps(); app++)
{
if (_multi_app->hasLocalApp(app))
{
MPI_Comm swapped = Moose::swapLibMeshComm(_multi_app->comm());
projectSolution(*_multi_app->appProblem(app), app);
Moose::swapLibMeshComm(swapped);
}
}
}
void
MultiAppProjectionTransfer::fromMultiApp()
{
Moose::out << "Projecting solution" << std::endl;
projectSolution(*_multi_app->problem(), 0);
}
void
MultiAppProjectionTransfer::execute()
{
_console << "Beginning projection transfer " << name() << std::endl;
getAppInfo();
////////////////////
// We are going to project the solutions by solving some linear systems. In
// order to assemble the systems, we need to evaluate the "from" domain
// solutions at quadrature points in the "to" domain. Some parallel
// communication is necessary because each processor doesn't necessarily have
// all the "from" information it needs to set its "to" values. We don't want
// to use a bunch of big all-to-all broadcasts, so we'll use bounding boxes to
// figure out which processors have the information we need and only
// communicate with those processors.
//
// Each processor will
// 1. Check its local quadrature points in the "to" domains to see which
// "from" domains they might be in.
// 2. Send quadrature points to the processors with "from" domains that might
// contain those points.
// 3. Recieve quadrature points from other processors, evaluate its mesh
// functions at those points, and send the values back to the proper
// processor
// 4. Recieve mesh function evaluations from all relevant processors and
// decide which one to use at every quadrature point (the lowest global app
// index always wins)
// 5. And use the mesh function evaluations to assemble and solve an L2
// projection system on its local elements.
////////////////////
////////////////////
// For every combination of global "from" problem and local "to" problem, find
// which "from" bounding boxes overlap with which "to" elements. Keep track
// of which processors own bounding boxes that overlap with which elements.
// Build vectors of quadrature points to send to other processors for mesh
// function evaluations.
////////////////////
// Get the bounding boxes for the "from" domains.
std::vector<MeshTools::BoundingBox> bboxes = getFromBoundingBoxes();
// Figure out how many "from" domains each processor owns.
std::vector<unsigned int> froms_per_proc = getFromsPerProc();
std::vector<std::vector<Point> > outgoing_qps(n_processors());
std::vector<std::map<std::pair<unsigned int, unsigned int>, unsigned int> > element_index_map(n_processors());
// element_index_map[i_to, element_id] = index
// outgoing_qps[index] is the first quadrature point in element
if (! _qps_cached)
{
for (unsigned int i_to = 0; i_to < _to_problems.size(); i_to++)
{
MeshBase & to_mesh = _to_meshes[i_to]->getMesh();
LinearImplicitSystem & system = * _proj_sys[i_to];
FEType fe_type = system.variable_type(0);
std::unique_ptr<FEBase> fe(FEBase::build(to_mesh.mesh_dimension(), fe_type));
QGauss qrule(to_mesh.mesh_dimension(), fe_type.default_quadrature_order());
fe->attach_quadrature_rule(&qrule);
const std::vector<Point> & xyz = fe->get_xyz();
MeshBase::const_element_iterator el = to_mesh.local_elements_begin();
const MeshBase::const_element_iterator end_el = to_mesh.local_elements_end();
unsigned int from0 = 0;
for (processor_id_type i_proc = 0;
i_proc < n_processors();
from0 += froms_per_proc[i_proc], i_proc++)
{
for (el = to_mesh.local_elements_begin(); el != end_el; el++)
{
const Elem* elem = *el;
fe->reinit (elem);
bool qp_hit = false;
for (unsigned int i_from = 0;
i_from < froms_per_proc[i_proc] && ! qp_hit; i_from++)
{
for (unsigned int qp = 0;
qp < qrule.n_points() && ! qp_hit; qp ++)
{
Point qpt = xyz[qp];
if (bboxes[from0 + i_from].contains_point(qpt + _to_positions[i_to]))
qp_hit = true;
}
}
if (qp_hit)
{
// The selected processor's bounding box contains at least one
// quadrature point from this element. Send all qps from this element
// and remember where they are in the array using the map.
std::pair<unsigned int, unsigned int> key(i_to, elem->id());
element_index_map[i_proc][key] = outgoing_qps[i_proc].size();
for (unsigned int qp = 0; qp < qrule.n_points(); qp ++)
{
Point qpt = xyz[qp];
outgoing_qps[i_proc].push_back(qpt + _to_positions[i_to]);
}
}
}
}
}
if (_fixed_meshes)
_cached_index_map = element_index_map;
}
else
{
element_index_map = _cached_index_map;
}
////////////////////
// Request quadrature point evaluations from other processors and handle
// requests sent to this processor.
////////////////////
// Non-blocking send quadrature points to other processors.
std::vector<Parallel::Request> send_qps(n_processors());
if (! _qps_cached)
for (processor_id_type i_proc = 0; i_proc < n_processors(); i_proc++)
if (i_proc != processor_id())
_communicator.send(i_proc, outgoing_qps[i_proc], send_qps[i_proc]);
// Get the local bounding boxes.
std::vector<MeshTools::BoundingBox> local_bboxes(froms_per_proc[processor_id()]);
{
// Find the index to the first of this processor's local bounding boxes.
unsigned int local_start = 0;
for (processor_id_type i_proc = 0;
i_proc < n_processors() && i_proc != processor_id();
i_proc++)
local_start += froms_per_proc[i_proc];
// Extract the local bounding boxes.
for (unsigned int i_from = 0; i_from < froms_per_proc[processor_id()]; i_from++)
local_bboxes[i_from] = bboxes[local_start + i_from];
}
// Setup the local mesh functions.
std::vector<MeshFunction *> local_meshfuns(froms_per_proc[processor_id()], NULL);
for (unsigned int i_from = 0; i_from < _from_problems.size(); i_from++)
{
FEProblemBase & from_problem = *_from_problems[i_from];
MooseVariable & from_var = from_problem.getVariable(0, _from_var_name);
System & from_sys = from_var.sys().system();
unsigned int from_var_num = from_sys.variable_number(from_var.name());
MeshFunction * from_func = new MeshFunction(from_problem.es(),
*from_sys.current_local_solution, from_sys.get_dof_map(), from_var_num);
from_func->init(Trees::ELEMENTS);
from_func->enable_out_of_mesh_mode(OutOfMeshValue);
local_meshfuns[i_from] = from_func;
}
// Recieve quadrature points from other processors, evaluate mesh frunctions
// at those points, and send the values back.
std::vector<Parallel::Request> send_evals(n_processors());
std::vector<Parallel::Request> send_ids(n_processors());
std::vector<std::vector<Real> > outgoing_evals(n_processors());
std::vector<std::vector<unsigned int> > outgoing_ids(n_processors());
std::vector<std::vector<Real> > incoming_evals(n_processors());
std::vector<std::vector<unsigned int> > incoming_app_ids(n_processors());
for (processor_id_type i_proc = 0; i_proc < n_processors(); i_proc++)
{
// Use the cached qps if they're available.
std::vector<Point> incoming_qps;
if (! _qps_cached)
{
if (i_proc == processor_id())
incoming_qps = outgoing_qps[i_proc];
else
_communicator.receive(i_proc, incoming_qps);
// Cache these qps for later if _fixed_meshes
if (_fixed_meshes)
_cached_qps[i_proc] = incoming_qps;
}
else
{
incoming_qps = _cached_qps[i_proc];
}
outgoing_evals[i_proc].resize(incoming_qps.size(), OutOfMeshValue);
if (_direction == FROM_MULTIAPP)
outgoing_ids[i_proc].resize(incoming_qps.size(), libMesh::invalid_uint);
for (unsigned int qp = 0; qp < incoming_qps.size(); qp++)
{
Point qpt = incoming_qps[qp];
// Loop until we've found the lowest-ranked app that actually contains
// the quadrature point.
for (unsigned int i_from = 0; i_from < _from_problems.size(); i_from++)
{
if (local_bboxes[i_from].contains_point(qpt))
{
outgoing_evals[i_proc][qp] = (* local_meshfuns[i_from])(qpt - _from_positions[i_from]);
if (_direction == FROM_MULTIAPP)
outgoing_ids[i_proc][qp] = _local2global_map[i_from];
}
}
}
if (i_proc == processor_id())
{
incoming_evals[i_proc] = outgoing_evals[i_proc];
if (_direction == FROM_MULTIAPP)
incoming_app_ids[i_proc] = outgoing_ids[i_proc];
}
else
{
_communicator.send(i_proc, outgoing_evals[i_proc], send_evals[i_proc]);
if (_direction == FROM_MULTIAPP)
_communicator.send(i_proc, outgoing_ids[i_proc], send_ids[i_proc]);
}
}
////////////////////
// Gather all of the qp evaluations and pick out the best ones for each qp.
////////////////////
for (processor_id_type i_proc = 0; i_proc < n_processors(); i_proc++)
{
if (i_proc == processor_id())
continue;
_communicator.receive(i_proc, incoming_evals[i_proc]);
if (_direction == FROM_MULTIAPP)
_communicator.receive(i_proc, incoming_app_ids[i_proc]);
}
std::vector<std::vector<Real> > final_evals(_to_problems.size());
std::vector<std::map<unsigned int, unsigned int> > trimmed_element_maps(_to_problems.size());
for (unsigned int i_to = 0; i_to < _to_problems.size(); i_to++)
{
MeshBase & to_mesh = _to_meshes[i_to]->getMesh();
LinearImplicitSystem & system = * _proj_sys[i_to];
FEType fe_type = system.variable_type(0);
std::unique_ptr<FEBase> fe(FEBase::build(to_mesh.mesh_dimension(), fe_type));
QGauss qrule(to_mesh.mesh_dimension(), fe_type.default_quadrature_order());
fe->attach_quadrature_rule(&qrule);
const std::vector<Point> & xyz = fe->get_xyz();
MeshBase::const_element_iterator el = to_mesh.local_elements_begin();
const MeshBase::const_element_iterator end_el = to_mesh.local_elements_end();
for (el = to_mesh.active_local_elements_begin(); el != end_el; el++)
{
const Elem* elem = *el;
fe->reinit (elem);
bool element_is_evaled = false;
std::vector<Real> evals(qrule.n_points(), 0.);
for (unsigned int qp = 0; qp < qrule.n_points(); qp++)
{
Point qpt = xyz[qp];
unsigned int lowest_app_rank = libMesh::invalid_uint;
for (unsigned int i_proc = 0; i_proc < n_processors(); i_proc++)
{
// Ignore the selected processor if the element wasn't found in it's
// bounding box.
std::map<std::pair<unsigned int, unsigned int>, unsigned int> & map = element_index_map[i_proc];
std::pair<unsigned int, unsigned int> key(i_to, elem->id());
if (map.find(key) == map.end())
continue;
unsigned int qp0 = map[key];
// Ignore the selected processor if it's app has a higher rank than the
// previously found lowest app rank.
if (_direction == FROM_MULTIAPP)
if (incoming_app_ids[i_proc][qp0 + qp] >= lowest_app_rank)
continue;
// Ignore the selected processor if the qp was actually outside the
// processor's subapp's mesh.
if (incoming_evals[i_proc][qp0 + qp] == OutOfMeshValue)
continue;
// This is the best meshfunction evaluation so far, save it.
element_is_evaled = true;
evals[qp] = incoming_evals[i_proc][qp0 + qp];
}
}
// If we found good evaluations for any of the qps in this element, save
// those evaluations for later.
if (element_is_evaled)
{
trimmed_element_maps[i_to][elem->id()] = final_evals[i_to].size();
for (unsigned int qp = 0; qp < qrule.n_points(); qp++)
final_evals[i_to].push_back(evals[qp]);
}
}
}
////////////////////
// We now have just one or zero mesh function values at all of our local
// quadrature points. Stash those values (and a map linking them to element
// ids) in the equation systems parameters and project the solution.
////////////////////
for (unsigned int i_to = 0; i_to < _to_problems.size(); i_to++)
{
_to_es[i_to]->parameters.set<std::vector<Real>*>("final_evals") = & final_evals[i_to];
_to_es[i_to]->parameters.set<std::map<unsigned int, unsigned int>*>("element_map") = & trimmed_element_maps[i_to];
projectSolution(i_to);
_to_es[i_to]->parameters.set<std::vector<Real>*>("final_evals") = NULL;
_to_es[i_to]->parameters.set<std::map<unsigned int, unsigned int>*>("element_map") = NULL;
}
for (unsigned int i = 0; i < _from_problems.size(); i++)
delete local_meshfuns[i];
// Make sure all our sends succeeded.
for (processor_id_type i_proc = 0; i_proc < n_processors(); i_proc++)
{
if (i_proc == processor_id())
continue;
if (! _qps_cached)
send_qps[i_proc].wait();
send_evals[i_proc].wait();
if (_direction == FROM_MULTIAPP)
send_ids[i_proc].wait();
}
if (_fixed_meshes)
_qps_cached = true;
_console << "Finished projection transfer " << name() << std::endl;
}
