hierarchGeomDecomp.H

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License
    This file is part of OpenFOAM.
 
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Class
    Foam::hierarchGeomDecomp
 
Description
    Does hierarchical decomposition of points. Works by first sorting the
    points in x direction into equal sized bins, then in y direction and
    finally in z direction.
 
    Uses single array to hold decomposition which is indexed as if it is a
    3 dimensional array:
 
        finalDecomp[i,j,k] is indexed as
 
        i*n[0]*n[1] + j*n[1] + k
 
    E.g. if we're sorting 'xyz': the first sort (over the x-component)
    determines in which x-domain the point goes. Then for each of the x-domains
    the points are sorted in y direction and each individual x-domain gets
    split into three y-domains. And similar for the z-direction.
 
    Since the domains are of equal size the maximum difference in size is
    n[0]*n[1] (or n[1]*n[2]?) (small anyway)
 
 
SourceFiles
    hierarchGeomDecomp.C
 
\*---------------------------------------------------------------------------*/
 
#ifndef hierarchGeomDecomp_H
#define hierarchGeomDecomp_H
 
#include "geomDecomp.H"
#include "FixedList.H"
#include "direction.H"
 
namespace Foam
{
 
/*---------------------------------------------------------------------------*\
                     Class hierarchGeomDecomp Declaration
\*---------------------------------------------------------------------------*/
 
class hierarchGeomDecomp
:
    public geomDecomp
{
    // Private Data
 
        //- Decomposition order in terms of components.
        FixedList<direction, 3> decompOrder_;
 
 
    // Private Member Functions
 
        //- Convert ordering string ("xyz") into list of components.
        void setDecompOrder();
 
        //- Evaluates the weighted sizes for each sorted point.
        static void calculateSortedWeightedSizes
        (
            const labelList& current,
            const labelList& indices,
            const scalarField& weights,
            const label globalCurrentSize,
 
            scalarField& sortedWeightedSizes
        );
 
        //- Find index of t in list in between indices left and right
        static label findLower
        (
            const List<scalar>&,
            const scalar t,
            const label left,
            const label right
        );
 
        //- Find midValue (at local index mid) such that the number of
        //  elements between mid and leftIndex are (globally summed) the
        //  wantedSize. Binary search.
        static void findBinary
        (
            const label sizeTol,        // size difference considered acceptable
            const List<scalar>&,
            const label leftIndex,      // index of previous value
            const scalar leftValue,     // value at leftIndex
            const scalar maxValue,      // global max of values
            const scalar wantedSize,    // wanted size
            label& mid,                 // index where size of bin is wantedSize
            scalar& midValue            // value at mid
        );
 
        //- Find midValue (at local index mid) such that the number of
        //  elements between mid and leftIndex are (globally summed) the
        //  wantedSize. Binary search.
        static void findBinary
        (
            const label sizeTol,        // size difference considered acceptable
            const List<scalar>& sortedWeightedSizes,
            const List<scalar>&,
            const label leftIndex,      // index of previous value
            const scalar leftValue,     // value at leftIndex
            const scalar maxValue,      // global max of values
            const scalar wantedSize,    // wanted size
            label& mid,                 // index where size of bin is wantedSize
            scalar& midValue            // value at mid
        );
 
        //- Recursively sort in x,y,z (or rather acc. to decompOrder_)
        void sortComponent
        (
            const label sizeTol,
            const pointField&,
            const labelList& slice,         // slice of points to decompose
            const direction componentIndex, // index in decompOrder_
            const label prevMult,           // multiplication factor
            labelList& finalDecomp          // overall decomposition
        );
 
        //- Recursively sort in x,y,z (or rather acc. to decompOrder_)
        //- Using weighted points.
        void sortComponent
        (
            const label sizeTol,
            const scalarField& weights,
            const pointField&,
            const labelList& slice,         // slice of points to decompose
            const direction componentIndex, // index in decompOrder_
            const label prevMult,           // multiplication factor
            labelList& finalDecomp          // overall decomposition
        );
 
 
public:
 
    //- Runtime type information
    TypeName("hierarchical");
 
 
    // Constructors
 
        //- Construct given the decomposition dictionary
        hierarchGeomDecomp(const dictionary& decompositionDict);
 
        //- Disallow default bitwise copy construction
        hierarchGeomDecomp(const hierarchGeomDecomp&) = delete;
 
 
    //- Destructor
    virtual ~hierarchGeomDecomp()
    {}
 
 
    // Member Functions
 
        //- Return for every coordinate the wanted processor number.
        virtual labelList decompose
        (
            const pointField&,
            const scalarField& weights
        );
 
        //- Without weights. Code for weighted decomposition is a bit complex
        //  so kept separate for now.
        virtual labelList decompose(const pointField&);
 
 
        //- Return for every coordinate the wanted processor number. Use the
        //  mesh connectivity (if needed)
        virtual labelList decompose
        (
            const polyMesh& mesh,
            const pointField& cc,
            const scalarField& cWeights
        )
        {
            return decompose(cc, cWeights);
        }
 
        //- Without weights. Code for weighted decomposition is a bit complex
        //  so kept separate for now.
        virtual labelList decompose(const polyMesh& mesh, const pointField& cc)
        {
            return decompose(cc);
        }
 
        //- Return for every coordinate the wanted processor number. Explicitly
        //  provided connectivity - does not use mesh_.
        //  The connectivity is equal to mesh.cellCells() except for
        //  - in parallel the cell numbers are global cell numbers (starting
        //    from 0 at processor0 and then incrementing all through the
        //    processors)
        //  - the connections are across coupled patches
        virtual labelList decompose
        (
            const labelListList& globalCellCells,
            const pointField& cc,
            const scalarField& cWeights
        )
        {
            return decompose(cc, cWeights);
        }
 
        virtual labelList decompose
        (
            const labelListList& globalCellCells,
            const pointField& cc
        )
        {
            return decompose(cc);
        }
 
 
    // Member Operators
 
        //- Disallow default bitwise assignment
        void operator=(const hierarchGeomDecomp&) = delete;
};
 
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
} // End namespace Foam
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
#endif
 
// ************************************************************************* //