Index Cheatsheet

For the following (default / template configuration):

• an MD30 domain
• cell size 2.5 (i.e. linked cell size and macroscopic cell size)
• outermost-overlap-layer="2"
• innermost-overlap-layer="3"

you will yield this structure:

0	1	2	3	4	5	6	7	8	9	10	11	12	13
GL	M	VEL	VEL	MD2M	MD2M	MD2M	MD2M	MD2M	MD2M	VEL	VEL	M	GL

where the upper row contains the global index of the macroscopic cell (in one of the spatial dimensions, i.e. one of the components of a vector index), and the lower row contains the type of the cell:

• GL = ghost layer, i.e. macroscopic cell outside the MD domain
• M = mass transfer, cell where USHER is active, if enabled
• VEL = velocity transfer cell, macro -> MD
• MD2M = 'MD -> Macro' domain = i.e. filtering domain = 'inner' MD domain

Lookup for shorthands/types

Alias	Idx_T_ID	IndexTrait::vector	IndexTrait::local	IndexTrait::md2macro	IndexTrait::noGhost	Used in
IdxSGAH	I00
IdxVGAH, BaseIndex	I01	X
IdxSLAH	I02		X			MamicoLammpsMDSolverInterface
IdxVLAH	I03	X	X
IdxSGIH	I04			X
IdxVGIH	I05	X		X
IdxSLIH	I06		X	X
IdxVLIH	I07	X	X	X
IdxSGAO	I08				X
IdxVGAO	I09	X			X
IdxSLAO	I10		X		X	CouplingCellService
IdxVLAO	I11	X	X		X	MDSolverInterface
IdxSGIO	I12			X	X
IdxVGIO	I13	X		X	X	NLM
IdxSLIO	I14		X	X	X	FilterInterface
IdxVLIO	I15	X	X	X	X	NLM

Indexing refactoring cheatsheet

Legacy		New System
indexConversion.getThisRank()	= >	IDXS.getRank()
indexConversion.getLocalNumberCouplingCells()	= >	I11::numberCellsInDomain
indexConversion.getGlobalNumberCouplingCells()	= >	I09::numberCellsInDomain
TransferStrategy::getLocalNumberCouplingCells()	= >	I02::linearNumberCellsInDomain
indexConversion.getCouplingCellSize()	= >	IDXS.getCouplingCellSize()
_indexConversion->getRanksForCouplingCell()	= >	IDXS.getRanksForGlobalIndex(idx)
_indexConversion->getUniqueRankForCouplingCell(idx)	= >	IDXS.getUniqueRankForCouplingCell(idx)
_indexConversion->getGlobalMDDomainOffset()	= >	IDXS.getGlobalMDDomainOffset()
_indexConversion->getGlobalMDDomainSize()	= >	IDXS.getGlobalMDDomainSize()

Legacy

const tarch::la::Vector<3, unsigned int> globalIndex(indexConversion.getGlobalVectorCellIndex(_buf.globalCellIndices4RecvBuffer[i]));
tarch::la::Vector<3, double> cellMidPoint(domainOffset - 0.5 * macroscopicCellSize);
for (unsigned int d = 0; d < 3; d++) {
   cellMidPoint[d] = cellMidPoint[d] + ((double)globalIndex[d]) * macroscopicCellSize[d];
}

New System

auto midPoint = _buf.globalCellIndices4RecvBuffer[i].getCellMidPoint();

---

Legacy

const tarch::la::Vector<3, unsigned int> cells(indexConversion.getGlobalNumberMacroscopicCells() + tarch::la::Vector<3, unsigned int>(2));
const unsigned int num = cells[0] * cells[1] * cells[2];
unsigned int numCellsSent = 0;
for (unsigned int i = 0; i < num; i++) {
  if (couetteSolverInterface.sendMacroscopicQuantityToMDSolver(indexConversion.getGlobalVectorCellIndex(i))) {
    std::vector<unsigned int> ranks = couetteSolverInterface.getSourceRanks(indexConversion.getGlobalVectorCellIndex(i));
    bool containsThisRank = false;
    for (unsigned int k = 0; k < ranks.size(); k++) {
      containsThisRank = containsThisRank || (ranks[k] == (unsigned int)_rank);
    }
    if (containsThisRank) {
      numCellsSent++;
    }
  }
}

New System

for (auto idx : I00())
  if (!I12::contains(idx))
    if (tarch::utils::contains(msi.getSourceRanks(idx), (unsigned int)_rank))
      numCellsSent++;

---

Legacy

some_function(const unsigned int index) {
  const tarch::la::Vector<dim, unsigned int> globalIndex(
    coupling::transferstrategies::TransferStrategy<LinkedCell, dim>::_indexConversion.convertLocalToGlobalVectorCellIndex(
      coupling::transferstrategies::TransferStrategy<LinkedCell, dim>::_indexConversion.getLocalVectorCellIndex(index)));
  const tarch::la::Vector<dim, unsigned int> globalNumberCells(
    coupling::transferstrategies::TransferStrategy<LinkedCell, dim>::_indexConversion.getGlobalNumberMacroscopicCells());

  const tarch::la::Vector<dim, double> meshsize(coupling::transferstrategies::TransferStrategy<LinkedCell,dim>
    ::_indexConversion.getMacroscopicCellSize());

  if(globalIndex[0] == globalNumberCells[0]) do_sth();
}

New System

some_function(I01 index) {
  const tarch::la::Vector<dim, double> meshsize(IDXS.getCouplingCellSize());

  if(index.get()[0] == I09::numberCellsInDomain[0]) do_sth();
}

---

Legacy

const tarch::la::Vector<3, unsigned int> start(0);
const tarch::la::Vector<3, unsigned int> end =
  start + coupling::initRange<dim>(indexConversion.getLocalNumberCouplingCells() + tarch::la::Vector<dim, unsigned int>(2));
tarch::la::Vector<3, unsigned int> loop(0);

for (loop[2] = start[2]; loop[2] < end[2]; loop[2]++) {
  for (loop[1] = start[1]; loop[1] < end[1]; loop[1]++) {
    for (loop[0] = start[0]; loop[0] < end[0]; loop[0]++) {
      // determine global vector cell index of this cell
      tarch::la::Vector<dim, unsigned int> globalVectorIndex = coupling::initDimVector<dim>(loop);
      globalVectorIndex = indexConversion.convertLocalToGlobalVectorCellIndex(globalVectorIndex);

      // call allocateReceiveBuffers for this cell
      coupling::sendrecv::SendReceiveBuffer<CouplingCell, dim>::allocateReceiveBuffers(dataExchange, globalVectorIndex);
    }
  }
}

New System

for (auto idx : I02())
  coupling::sendrecv::SendReceiveBuffer<CouplingCell, dim>::allocateReceiveBuffers(dataExchange, idx);