MueLu_LineDetectionFactory_def.hpp

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#ifndef MUELU_LINEDETECTIONFACTORY_DEF_HPP
#define MUELU_LINEDETECTIONFACTORY_DEF_HPP

#include <Xpetra_Matrix.hpp>
//#include <Xpetra_MatrixFactory.hpp>

#include "MueLu_LineDetectionFactory_decl.hpp"

#include "MueLu_FactoryManager.hpp"
#include "MueLu_Level.hpp"
#include "MueLu_MasterList.hpp"
#include "MueLu_Monitor.hpp"

namespace MueLu {

  template <class Scalar, class LocalOrdinal, class GlobalOrdinal, class Node>
  RCP<const ParameterList> LineDetectionFactory<Scalar, LocalOrdinal, GlobalOrdinal, Node>::GetValidParameterList() const {
    RCP<ParameterList> validParamList = rcp(new ParameterList());

#define SET_VALID_ENTRY(name) validParamList->setEntry(name, MasterList::getEntry(name))
    SET_VALID_ENTRY("linedetection: orientation");
    SET_VALID_ENTRY("linedetection: num layers");
#undef  SET_VALID_ENTRY

    validParamList->set< RCP<const FactoryBase> >("A",               Teuchos::null, "Generating factory of the matrix A");
    validParamList->set< RCP<const FactoryBase> >("Coordinates",     Teuchos::null, "Generating factory for coorindates");

    return validParamList;
  }

  template <class Scalar, class LocalOrdinal, class GlobalOrdinal, class Node>
  void LineDetectionFactory<Scalar, LocalOrdinal, GlobalOrdinal, Node>::DeclareInput(Level& currentLevel) const {
    Input(currentLevel, "A");

    // The factory needs the information about the number of z-layers. While this information is
    // provided by the user for the finest level, the factory itself is responsible to provide the
    // corresponding information on the coarser levels. Since a factory cannot be dependent on itself
    // we use the NoFactory class as generator class, but remove the UserData keep flag, such that
    // "NumZLayers" is part of the request/release mechanism.
    // Please note, that this prevents us from having several (independent) CoarsePFactory instances!
    // TODO: allow factory to dependent on self-generated data for TwoLevelFactories -> introduce ExpertRequest/Release in Level
    currentLevel.DeclareInput("NumZLayers", NoFactory::get(), this);
    currentLevel.RemoveKeepFlag("NumZLayers", NoFactory::get(), MueLu::UserData);
  }

  template <class Scalar, class LocalOrdinal, class GlobalOrdinal, class Node>
  void LineDetectionFactory<Scalar, LocalOrdinal, GlobalOrdinal, Node>::Build(Level& currentLevel) const {
    FactoryMonitor m(*this, "Line detection (Ray style)", currentLevel);

    LO               NumZDir = 0;
    RCP<MultiVector> fineCoords;
    ArrayRCP<Scalar> x, y, z;
    Scalar           *xptr = NULL, *yptr = NULL, *zptr = NULL;

    // obtain general variables
    RCP<Matrix> A         = Get< RCP<Matrix> >      (currentLevel, "A");
    LO BlkSize            = A->GetFixedBlockSize();
    RCP<const Map> rowMap = A->getRowMap();
    LO Ndofs              = rowMap->getNodeNumElements();
    LO Nnodes             = Ndofs/BlkSize;

    // collect information provided by user
    const ParameterList& pL = GetParameterList();
    const std::string lineOrientation = pL.get<std::string>("linedetection: orientation");

    // interpret "line orientation" parameter provided by the user on the finest level
    if(currentLevel.GetLevelID() == 0) {
      if(lineOrientation=="vertical")
        Zorientation_ = VERTICAL;
      else if (lineOrientation=="horizontal")
        Zorientation_ = HORIZONTAL;
      else if (lineOrientation=="coordinates")
        Zorientation_ = GRID_SUPPLIED;
      else
        TEUCHOS_TEST_FOR_EXCEPTION(false, Exceptions::RuntimeError, "LineDetectionFactory: The parameter 'semicoarsen: line orientation' must be either 'vertical', 'horizontal' or 'coordinates'.");
    }

    //TEUCHOS_TEST_FOR_EXCEPTION(Zorientation_!=VERTICAL, Exceptions::RuntimeError, "LineDetectionFactory: The 'horizontal' or 'coordinates' have not been tested!!!. Please remove this exception check and carefully test these modes!");

    // obtain number of z layers (variable over levels)
    // This information is user-provided on the finest level and transferred to the coarser
    // levels by the SemiCoarsenPFactor using the internal "NumZLayers" variable.
    if(currentLevel.GetLevelID() == 0) {
      if(currentLevel.IsAvailable("NumZLayers", NoFactory::get())) {
        NumZDir = currentLevel.Get<LO>("NumZLayers", NoFactory::get()); //obtain info
        GetOStream(Runtime1) << "Number of layers for line detection: " << NumZDir << " (information from Level(0))" << std::endl;
      } else {
        // check whether user provides information or it can be reconstructed from coordinates
        NumZDir = pL.get<LO>("linedetection: num layers");
        if(NumZDir == -1) {
          bool CoordsAvail = currentLevel.IsAvailable("Coordinates");

          if (CoordsAvail == true) {
            // try to reconstruct the number of layers from coordinates
            fineCoords = Get< RCP<MultiVector> > (currentLevel, "Coordinates");
            TEUCHOS_TEST_FOR_EXCEPTION(fineCoords->getNumVectors() != 3, Exceptions::RuntimeError, "Three coordinates arrays must be supplied if line detection orientation not given.");
            x = fineCoords->getDataNonConst(0);
            y = fineCoords->getDataNonConst(1);
            z = fineCoords->getDataNonConst(2);
            xptr = x.getRawPtr();
            yptr = y.getRawPtr();
            zptr = z.getRawPtr();

            LO NumCoords = Ndofs/BlkSize;

            /* sort coordinates so that we can order things according to lines */
            Teuchos::ArrayRCP<LO> TOrigLoc= Teuchos::arcp<LO>(NumCoords);   LO* OrigLoc= TOrigLoc.getRawPtr();
            Teuchos::ArrayRCP<SC> Txtemp  = Teuchos::arcp<SC>(NumCoords);   SC* xtemp  = Txtemp.getRawPtr();
            Teuchos::ArrayRCP<SC> Tytemp  = Teuchos::arcp<SC>(NumCoords);   SC* ytemp  = Tytemp.getRawPtr();
            Teuchos::ArrayRCP<SC> Tztemp  = Teuchos::arcp<SC>(NumCoords);   SC* ztemp  = Tztemp.getRawPtr();

            // sort coordinates in {x,y,z}vals (returned in {x,y,z}temp) so that we can order things according to lines
            // switch x and y coordinates for semi-coarsening...
            sort_coordinates(NumCoords, OrigLoc, xptr, yptr, zptr, xtemp, ytemp, ztemp, true);

            /* go through each vertical line and populate blockIndices so all   */
            /* dofs within a PDE within a vertical line correspond to one block.*/
            LO NumBlocks = 0;
            LO NumNodesPerVertLine = 0;
            LO index = 0;

            while ( index < NumCoords ) {
              SC xfirst = xtemp[index]; SC yfirst = ytemp[index];
              LO next = index+1;
              while ( (next != NumCoords) && (xtemp[next] == xfirst) &&
                      (ytemp[next] == yfirst))
                next++;
              if (NumBlocks == 0) {
                NumNodesPerVertLine = next-index;
              }
              // the number of vertical lines must be the same on all processors
              // TAW: Sep 14 2015: or zero as we allow "empty" processors
              //TEUCHOS_TEST_FOR_EXCEPTION(next-index != NumNodesPerVertLine,Exceptions::RuntimeError, "Error code only works for constant block size now!!!\n");
              NumBlocks++;
              index = next;
            }

            NumZDir = NumNodesPerVertLine;
            GetOStream(Runtime1) << "Number of layers for line detection: " << NumZDir << " (information reconstructed from provided node coordinates)" << std::endl;
          } else {
            TEUCHOS_TEST_FOR_EXCEPTION(false, Exceptions::RuntimeError, "LineDetectionFactory: BuildP: User has to provide valid number of layers (e.g. using the 'line detection: num layers' parameter).");
          }
        } else {
          GetOStream(Runtime1) << "Number of layers for line detection: " << NumZDir << " (information provided by user through 'line detection: num layers')" << std::endl;
        }
      } // end else (user provides information or can be reconstructed) on finest level
    } else {
      // coarse level information
      // TODO get rid of NoFactory here and use SemiCoarsenPFactory as source of NumZLayers instead.
      if(currentLevel.IsAvailable("NumZLayers", NoFactory::get())) {
        NumZDir = currentLevel.Get<LO>("NumZLayers", NoFactory::get()); //obtain info
        GetOStream(Runtime1) << "Number of layers for line detection: " << NumZDir << std::endl;
      } else {
        TEUCHOS_TEST_FOR_EXCEPTION(false, Exceptions::RuntimeError, "LineDetectionFactory: BuildP: No NumZLayers variable found. This cannot be.");
      }
    }

    // plausibility check and further variable collection
    if (Zorientation_ == GRID_SUPPLIED) { // On finest level, fetch user-provided coordinates if available...
      bool CoordsAvail = currentLevel.IsAvailable("Coordinates");

      if (CoordsAvail == false) {
        if (currentLevel.GetLevelID() == 0)
          throw Exceptions::RuntimeError("Coordinates must be supplied if line detection orientation not given.");
        else
          throw Exceptions::RuntimeError("Coordinates not generated by previous invocation of LineDetectionFactory's BuildP() method.");
      }
      fineCoords = Get< RCP<MultiVector> > (currentLevel, "Coordinates");
      TEUCHOS_TEST_FOR_EXCEPTION(fineCoords->getNumVectors() != 3, Exceptions::RuntimeError, "Three coordinates arrays must be supplied if line detection orientation not given.");
      x = fineCoords->getDataNonConst(0);
      y = fineCoords->getDataNonConst(1);
      z = fineCoords->getDataNonConst(2);
      xptr = x.getRawPtr();
      yptr = y.getRawPtr();
      zptr = z.getRawPtr();
    }

    // perform line detection
    if (NumZDir > 0) {
      LO   *LayerId, *VertLineId;
      Teuchos::ArrayRCP<LO>     TLayerId   = Teuchos::arcp<LO>(Nnodes);  LayerId       = TLayerId.getRawPtr();
      Teuchos::ArrayRCP<LO>     TVertLineId= Teuchos::arcp<LO>(Nnodes);  VertLineId    = TVertLineId.getRawPtr();

      NumZDir = ML_compute_line_info(LayerId, VertLineId, Ndofs, BlkSize,
                                     Zorientation_, NumZDir,xptr,yptr,zptr, *(rowMap->getComm()));
      //it is NumZDir=NCLayers*NVertLines*DofsPerNode;

      // store output data on current level
      // The line detection data is used by the SemiCoarsenPFactory and the line smoothers in Ifpack/Ifpack2
      Set(currentLevel, "CoarseNumZLayers", NumZDir);
      Set(currentLevel, "LineDetection_Layers", TLayerId);
      Set(currentLevel, "LineDetection_VertLineIds", TVertLineId);
    } else {
      Teuchos::ArrayRCP<LO>     TLayerId       = Teuchos::arcp<LO>(0);
      Teuchos::ArrayRCP<LO>     TVertLineId    = Teuchos::arcp<LO>(0);
      Teuchos::ArrayRCP<LO>     TVertLineIdSmoo= Teuchos::arcp<LO>(0);

      // store output data on current level
      // The line detection data is used by the SemiCoarsenPFactory and the line smoothers in Ifpack/Ifpack2
      Set(currentLevel, "CoarseNumZLayers", NumZDir);
      Set(currentLevel, "LineDetection_Layers", TLayerId);
      Set(currentLevel, "LineDetection_VertLineIds", TVertLineId);
    }

    // automatically switch to vertical mode on the coarser levels
    if(Zorientation_ != VERTICAL)
      Zorientation_ = VERTICAL;
  }

  template <class Scalar,class LocalOrdinal, class GlobalOrdinal, class Node>
  LocalOrdinal LineDetectionFactory<Scalar, LocalOrdinal, GlobalOrdinal, Node>::ML_compute_line_info(LocalOrdinal LayerId[], LocalOrdinal VertLineId[], LocalOrdinal Ndof, LocalOrdinal DofsPerNode, LocalOrdinal MeshNumbering, LocalOrdinal NumNodesPerVertLine, Scalar *xvals, Scalar *yvals, Scalar *zvals, const Teuchos::Comm<int>& /* comm */) const {

    LO    Nnodes, NVertLines, MyNode;
    LO    NumCoords, next; //, subindex, subnext;
    SC xfirst, yfirst;
    SC *xtemp, *ytemp, *ztemp;
    LO    *OrigLoc;
    LO    i,j,count;
    LO    RetVal;

    RetVal = 0;
    if ((MeshNumbering != VERTICAL) && (MeshNumbering != HORIZONTAL)) {
      if ( (xvals == NULL) || (yvals == NULL) || (zvals == NULL)) RetVal = -1;
    }
    else {
      if  (NumNodesPerVertLine == -1)                     RetVal = -4;
      if ( ((Ndof/DofsPerNode)%NumNodesPerVertLine) != 0) RetVal = -3;
    }
    if ( (Ndof%DofsPerNode) != 0) RetVal = -2;

    TEUCHOS_TEST_FOR_EXCEPTION(RetVal == -1, Exceptions::RuntimeError, "Not semicoarsening as no mesh numbering information or coordinates are given\n");
    TEUCHOS_TEST_FOR_EXCEPTION(RetVal == -4, Exceptions::RuntimeError, "Not semicoarsening as the number of z nodes is not given.\n");
    TEUCHOS_TEST_FOR_EXCEPTION(RetVal == -3, Exceptions::RuntimeError, "Not semicoarsening as the total number of nodes is not evenly divisible by the number of z direction nodes .\n");
    TEUCHOS_TEST_FOR_EXCEPTION(RetVal == -2, Exceptions::RuntimeError, "Not semicoarsening as something is off with the number of degrees-of-freedom per node.\n");

    Nnodes = Ndof/DofsPerNode;
    for (MyNode = 0; MyNode < Nnodes;  MyNode++) VertLineId[MyNode]    = -1;
    for (MyNode = 0; MyNode < Nnodes;  MyNode++) LayerId[MyNode]       = -1;

    if (MeshNumbering == VERTICAL) {
      for (MyNode = 0; MyNode < Nnodes; MyNode++) {
        LayerId[MyNode]= MyNode%NumNodesPerVertLine;
        VertLineId[MyNode]= (MyNode- LayerId[MyNode])/NumNodesPerVertLine;
      }
    }
    else if (MeshNumbering == HORIZONTAL) {
      NVertLines = Nnodes/NumNodesPerVertLine;
      for (MyNode = 0; MyNode < Nnodes; MyNode++) {
        VertLineId[MyNode]    = MyNode%NVertLines;
        LayerId[MyNode]   = (MyNode- VertLineId[MyNode])/NVertLines;
      }
    }
    else {
      // coordinates mode: we distinguish between vertical line numbering for semi-coarsening and line smoothing
      NumCoords = Ndof/DofsPerNode;

      // reserve temporary memory
      Teuchos::ArrayRCP<LO> TOrigLoc= Teuchos::arcp<LO>(NumCoords);       OrigLoc= TOrigLoc.getRawPtr();
      Teuchos::ArrayRCP<SC> Txtemp  = Teuchos::arcp<SC>(NumCoords);       xtemp  = Txtemp.getRawPtr();
      Teuchos::ArrayRCP<SC> Tytemp  = Teuchos::arcp<SC>(NumCoords);       ytemp  = Tytemp.getRawPtr();
      Teuchos::ArrayRCP<SC> Tztemp  = Teuchos::arcp<SC>(NumCoords);       ztemp  = Tztemp.getRawPtr();

      // build vertical line info for semi-coarsening

      // sort coordinates in {x,y,z}vals (returned in {x,y,z}temp) so that we can order things according to lines
      // switch x and y coordinates for semi-coarsening...
      sort_coordinates(NumCoords, OrigLoc, xvals, yvals, zvals, xtemp, ytemp, ztemp, /*true*/ true);

      LO NumBlocks = 0;
      LO index = 0;

      while ( index < NumCoords ) {
        xfirst = xtemp[index];  yfirst = ytemp[index];
        next = index+1;
        while ( (next != NumCoords) && (xtemp[next] == xfirst) &&
                (ytemp[next] == yfirst))
          next++;
        if (NumBlocks == 0) {
          NumNodesPerVertLine = next-index;
        }
        // The number of vertical lines must be the same on all processors
        // TAW: Sep 14, 2015: or zero as we allow for empty processors.
        //TEUCHOS_TEST_FOR_EXCEPTION(next-index != NumNodesPerVertLine,Exceptions::RuntimeError, "Error code only works for constant block size now!!!\n");
        count = 0;
        for (j= index; j < next; j++) {
          VertLineId[OrigLoc[j]] = NumBlocks;
          LayerId[OrigLoc[j]] = count++;
        }
        NumBlocks++;
        index = next;
      }
    }

    /* check that everyone was assigned */

    for (i = 0; i < Nnodes;  i++) {
      if (VertLineId[i] == -1) {
        GetOStream(Warnings1) << "Warning: did not assign " << i << " to a vertical line?????\n" << std::endl;
      }
      if (LayerId[i] == -1) {
        GetOStream(Warnings1) << "Warning: did not assign " << i << " to a Layer?????\n" << std::endl;
      }
    }

    // TAW: Sep 14 2015: relax plausibility checks as we allow for empty processors
    //MueLu_maxAll(&comm, NumNodesPerVertLine, i);
    //if (NumNodesPerVertLine == -1)  NumNodesPerVertLine = i;
    //TEUCHOS_TEST_FOR_EXCEPTION(NumNodesPerVertLine != i,Exceptions::RuntimeError, "Different processors have different z direction line lengths?\n");

    return NumNodesPerVertLine;
  }

  /* Private member function to sort coordinates in arrays. This is an expert routine. Do not use or change.*/
  template <class Scalar,class LocalOrdinal, class GlobalOrdinal, class Node>
  void LineDetectionFactory<Scalar, LocalOrdinal, GlobalOrdinal, Node>::sort_coordinates(LO numCoords, LO* OrigLoc, Scalar* xvals, Scalar* yvals, Scalar* zvals, Scalar* xtemp, Scalar* ytemp, Scalar* ztemp, bool flipXY) const {

    if( flipXY == false ) { // for line-smoothing
      for (LO i = 0; i < numCoords; i++) xtemp[i]= xvals[i];
    } else { // for semi-coarsening
      for (LO i = 0; i < numCoords; i++) xtemp[i]= yvals[i];
    }
    for (LO i = 0; i < numCoords; i++) OrigLoc[i]= i;

    ML_az_dsort2(xtemp,numCoords,OrigLoc);
    if( flipXY == false ) { // for line-smoothing
      for (LO i = 0; i < numCoords; i++) ytemp[i]= yvals[OrigLoc[i]];
    } else {
      for (LO i = 0; i < numCoords; i++) ytemp[i]= xvals[OrigLoc[i]];
    }

    LO index = 0;

    while ( index < numCoords ) {
      SC xfirst = xtemp[index];
      LO next   = index+1;
      while ( (next != numCoords) && (xtemp[next] == xfirst))
        next++;
      ML_az_dsort2(&(ytemp[index]),next-index,&(OrigLoc[index]));
      for (LO i = index; i < next; i++) ztemp[i]= zvals[OrigLoc[i]];
      /* One final sort so that the ztemps are in order */
      LO subindex = index;
      while (subindex != next) {
        SC yfirst = ytemp[subindex];
        LO subnext = subindex+1;
        while ( (subnext != next) && (ytemp[subnext] == yfirst)) subnext++;
        ML_az_dsort2(&(ztemp[subindex]),subnext-subindex,&(OrigLoc[subindex]));
        subindex = subnext;
      }
      index = next;
    }

  }

  /* Sort coordinates and additional array accordingly (if provided). This is an expert routine borrowed from ML. Do not change.*/
  template <class Scalar,class LocalOrdinal, class GlobalOrdinal, class Node>
  void LineDetectionFactory<Scalar, LocalOrdinal, GlobalOrdinal, Node>::ML_az_dsort2(Scalar dlist[], LocalOrdinal N, LocalOrdinal list2[]) const {
    LO l, r, j, i, flag;
    LO RR2;
    SC       dRR, dK;

    // note: we use that routine for sorting coordinates only. No complex coordinates are assumed...
    typedef Teuchos::ScalarTraits<SC> STS;

    if (N <= 1) return;

    l    = N / 2 + 1;
    r    = N - 1;
    l    = l - 1;
    dRR  = dlist[l - 1];
    dK   = dlist[l - 1];

    if (list2 != NULL) {
      RR2 = list2[l - 1];
      while (r != 0) {
        j = l;
        flag = 1;

        while (flag == 1) {
          i = j;
          j = j + j;

          if (j > r + 1)
            flag = 0;
          else {
            if (j < r + 1)
              if (STS::real(dlist[j]) > STS::real(dlist[j - 1])) j = j + 1;

            if (STS::real(dlist[j - 1]) > STS::real(dK)) {
              dlist[ i - 1] = dlist[ j - 1];
              list2[i - 1] = list2[j - 1];
            }
            else {
              flag = 0;
            }
          }
        }
        dlist[ i - 1] = dRR;
        list2[i - 1] = RR2;

        if (l == 1) {
          dRR  = dlist [r];
          RR2 = list2[r];
          dK = dlist[r];
          dlist[r ] = dlist[0];
          list2[r] = list2[0];
          r = r - 1;
        }
        else {
          l   = l - 1;
          dRR  = dlist[ l - 1];
          RR2 = list2[l - 1];
          dK   = dlist[l - 1];
        }
      }
      dlist[ 0] = dRR;
      list2[0] = RR2;
    }
    else {
      while (r != 0) {
        j = l;
        flag = 1;
        while (flag == 1) {
          i = j;
          j = j + j;
          if (j > r + 1)
            flag = 0;
          else {
            if (j < r + 1)
              if (STS::real(dlist[j]) > STS::real(dlist[j - 1])) j = j + 1;
            if (STS::real(dlist[j - 1]) > STS::real(dK)) {
              dlist[ i - 1] = dlist[ j - 1];
            }
            else {
              flag = 0;
            }
          }
        }
        dlist[ i - 1] = dRR;
        if (l == 1) {
          dRR  = dlist [r];
          dK = dlist[r];
          dlist[r ] = dlist[0];
          r = r - 1;
        }
        else {
          l   = l - 1;
          dRR  = dlist[ l - 1];
          dK   = dlist[l - 1];
        }
      }
      dlist[ 0] = dRR;
    }

  }
} //namespace MueLu

#endif // MUELU_LINEDETECTIONFACTORY_DEF_HPP